WorldWideScience

Sample records for rocket engine exhaust

  1. Schlieren image velocimetry measurements in a rocket engine exhaust plume

    Science.gov (United States)

    Morales, Rudy; Peguero, Julio; Hargather, Michael

    2017-11-01

    Schlieren image velocimetry (SIV) measures velocity fields by tracking the motion of naturally-occurring turbulent flow features in a compressible flow. Here the technique is applied to measuring the exhaust velocity profile of a liquid rocket engine. The SIV measurements presented include discussion of visibility of structures, image pre-processing for structure visibility, and ability to process resulting images using commercial particle image velocimetry (PIV) codes. The small-scale liquid bipropellant rocket engine operates on nitrous oxide and ethanol as propellants. Predictions of the exhaust velocity are obtained through NASA CEA calculations and simple compressible flow relationships, which are compared against the measured SIV profiles. Analysis of shear layer turbulence along the exhaust plume edge is also presented.

  2. Investigation of Cooling Water Injection into Supersonic Rocket Engine Exhaust

    Science.gov (United States)

    Jones, Hansen; Jeansonne, Christopher; Menon, Shyam

    2017-11-01

    Water spray cooling of the exhaust plume from a rocket undergoing static testing is critical in preventing thermal wear of the test stand structure, and suppressing the acoustic noise signature. A scaled test facility has been developed that utilizes non-intrusive diagnostic techniques including Focusing Color Schlieren (FCS) and Phase Doppler Particle Anemometry (PDPA) to examine the interaction of a pressure-fed water jet with a supersonic flow of compressed air. FCS is used to visually assess the interaction of the water jet with the strong density gradients in the supersonic air flow. PDPA is used in conjunction to gain statistical information regarding water droplet size and velocity as the jet is broken up. Measurement results, along with numerical simulations and jet penetration models are used to explain the observed phenomena. Following the cold flow testing campaign a scaled hybrid rocket engine will be constructed to continue tests in a combusting flow environment similar to that generated by the rocket engines tested at NASA facilities. LaSPACE.

  3. High-speed schlieren imaging of rocket exhaust plumes

    Science.gov (United States)

    Coultas-McKenney, Caralyn; Winter, Kyle; Hargather, Michael

    2016-11-01

    Experiments are conducted to examine the exhaust of a variety of rocket engines. The rocket engines are mounted in a schlieren system to allow high-speed imaging of the engine exhaust during startup, steady state, and shutdown. A variety of rocket engines are explored including a research-scale liquid rocket engine, consumer/amateur solid rocket motors, and water bottle rockets. Comparisons of the exhaust characteristics, thrust and cost for this range of rockets is presented. The variety of nozzle designs, target functions, and propellant type provides unique variations in the schlieren imaging.

  4. Liquid Rocket Engine Testing

    Science.gov (United States)

    2016-10-21

    Briefing Charts 3. DATES COVERED (From - To) 17 October 2016 – 26 October 2016 4. TITLE AND SUBTITLE Liquid Rocket Engine Testing 5a. CONTRACT NUMBER...298 (Rev. 8-98) Prescribed by ANSI Std. 239.18 Liquid Rocket Engine Testing SFTE Symposium 21 October 2016 Jake Robertson, Capt USAF AFRL...Distribution Unlimited. PA Clearance 16493 Liquid Rocket Engine Testing • Engines and their components are extensively static-tested in development • This

  5. Study on the Effect of water Injection Momentum on the Cooling Effect of Rocket Engine Exhaust Plume

    Science.gov (United States)

    Yang, Kan; Qiang, Yanhui; Zhong, Chenghang; Yu, Shaozhen

    2017-10-01

    For the study of water injection momentum factors impact on flow field of the rocket engine tail flame, the numerical computation model of gas-liquid two phase flow in the coupling of high temperature and high speed gas flow and low temperature liquid water is established. The accuracy and reliability of the numerical model are verified by experiments. Based on the numerical model, the relationship between the flow rate and the cooling effect is analyzed by changing the water injection momentum of the water spray pipes. And the effective mathematical expression is obtained. What’s more, by changing the number of the water spray and using small flow water injection, the cooling effect is analyzed to check the application range of the mathematical expressions. The results show that: the impact and erosion of the gas flow field could be reduced greatly by water injection, and there are two parts in the gas flow field, which are the slow cooling area and the fast cooling area. In the fast cooling area, the influence of the water flow momentum and nozzle quantity on the cooling effect can be expressed by mathematical functions without causing bifurcation flow for the mainstream gas. The conclusion provides a theoretical reference for the engineering application.

  6. Liquid Rocket Engine Testing

    Science.gov (United States)

    Rahman, Shamim

    2005-01-01

    Comprehensive Liquid Rocket Engine testing is essential to risk reduction for Space Flight. Test capability represents significant national investments in expertise and infrastructure. Historical experience underpins current test capabilities. Test facilities continually seek proactive alignment with national space development goals and objectives including government and commercial sectors.

  7. Cryogenic rocket engine development at Delft aerospace rocket engineering

    NARCIS (Netherlands)

    Wink, J; Hermsen, R.; Huijsman, R; Akkermans, C.; Denies, L.; Barreiro, F.; Schutte, A.; Cervone, A.; Zandbergen, B.T.C.

    2016-01-01

    This paper describes the current developments regarding cryogenic rocket engine technology at Delft Aerospace Rocket Engineering (DARE). DARE is a student society based at Delft University of Technology with the goal of being the first student group in the world to launch a rocket into space. After

  8. Liquid Rocket Engine Testing Overview

    Science.gov (United States)

    Rahman, Shamim

    2005-01-01

    Contents include the following: Objectives and motivation for testing. Technology, Research and Development Test and Evaluation (RDT&E), evolutionary. Representative Liquid Rocket Engine (LRE) test compaigns. Apollo, shuttle, Expandable Launch Vehicles (ELV) propulsion. Overview of test facilities for liquid rocket engines. Boost, upper stage (sea-level and altitude). Statistics (historical) of Liquid Rocket Engine Testing. LOX/LH, LOX/RP, other development. Test project enablers: engineering tools, operations, processes, infrastructure.

  9. Nuclear Rocket Engine Reactor

    CERN Document Server

    Lanin, Anatoly

    2013-01-01

    The development of a nuclear rocket engine reactor (NRER ) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  10. Nuclear rocket engine reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lanin, Anatoly

    2013-07-01

    Covers a new technology of nuclear reactors and the related materials aspects. Integrates physics, materials science and engineering Serves as a basic book for nuclear engineers and nuclear physicists. The development of a nuclear rocket engine reactor (NRER) is presented in this book. The working capacity of an active zone NRER under mechanical and thermal load, intensive neutron fluxes, high energy generation (up to 30 MBT/l) in a working medium (hydrogen) at temperatures up to 3100 K is displayed. Design principles and bearing capacity of reactors area discussed on the basis of simulation experiments and test data of a prototype reactor. Property data of dense constructional, porous thermal insulating and fuel materials like carbide and uranium carbide compounds in the temperatures interval 300 - 3000 K are presented. Technological aspects of strength and thermal strength resistance of materials are considered. The design procedure of possible emergency processes in the NRER is developed and risks for their origination are evaluated. Prospects of the NRER development for pilotless space devices and piloted interplanetary ships are viewed.

  11. Evaluation of the Effect of Exhausts from Liquid and Solid Rockets on Ozone Layer

    Science.gov (United States)

    Yamagiwa, Yoshiki; Ishimaki, Tetsuya

    This paper reports the analytical results of the influences of solid rocket and liquid rocket exhausts on ozone layer. It is worried about that the exhausts from solid propellant rockets cause the ozone depletion in the ozone layer. Some researchers try to develop the analytical model of ozone depletion by rocket exhausts to understand its physical phenomena and to find the effective design of rocket to minimize its effect. However, these models do not include the exhausts from liquid rocket although there are many cases to use solid rocket boosters with a liquid rocket at the same time in practical situations. We constructed combined analytical model include the solid rocket exhausts and liquid rocket exhausts to analyze their effects. From the analytical results, we find that the exhausts from liquid rocket suppress the ozone depletion by solid rocket exhausts.

  12. Infrared Imagery of Solid Rocket Exhaust Plumes

    Science.gov (United States)

    Moran, Robert P.; Houston, Janice D.

    2011-01-01

    The Ares I Scale Model Acoustic Test program consisted of a series of 18 solid rocket motor static firings, simulating the liftoff conditions of the Ares I five-segment Reusable Solid Rocket Motor Vehicle. Primary test objectives included acquiring acoustic and pressure data which will be used to validate analytical models for the prediction of Ares 1 liftoff acoustics and ignition overpressure environments. The test article consisted of a 5% scale Ares I vehicle and launch tower mounted on the Mobile Launch Pad. The testing also incorporated several Water Sound Suppression Systems. Infrared imagery was employed during the solid rocket testing to support the validation or improvement of analytical models, and identify corollaries between rocket plume size or shape and the accompanying measured level of noise suppression obtained by water sound suppression systems.

  13. Effects of rocket exhaust products in the thermosphere and ionsphere

    International Nuclear Information System (INIS)

    Zinn, J.; Sutherland, C.D.

    1980-02-01

    This paper reviews the current state of understanding of the problem of ionospheric F-layer depletions produced by chemical effects of the exhaust gases from large rockets, with particular emphasis on the Heavy Lift Launch Vehicles (HLLV) proposed for use in the construction of solar power satellites. The currently planned HLLV flight profile calls for main second-stage propulsion confined to altitudes below 124 km, and a brief orbit circularization maneuver at apogee. The second stage engines deposit 9 x 10 31 H 2 O and H 2 molecules between 74 and 124 km. Model computations show that they diffuse gradually into the ionospheric F region, where they lead to weak but widespread and persistent depletions of ionization and continuous production of H atoms. The orbit circularization burn deposits 9 x 10 29 exhaust molecules at about 480-km altitude. These react rapidly with the F2 region 0 + ions, leading to a substantial (factor-of-three) reduction in plasma density, which extends over a 1000- by 2000-km region and persists for four to five hours. For purposes of computer model verification, a computation is included representing the Skylab I launch, for which observational data exist. The computations and data are compared, and the computer model is described

  14. Numerical Simulation of Ionospheric Electron Concentration Depletion by Rocket Exhaust

    International Nuclear Information System (INIS)

    Huang Yong; Shi Jiaming; Yuan Zhongcai

    2011-01-01

    In terms of the diffusive process of the gases injected from rocket exhaust into the ionosphere and the relevant chemical reactions between the gases and the composition of ionosphere, the modifications in ionosphere caused by the injected hydrogen and carbon dioxide gas from the rocket exhaust are investigated. The results show that the diffusive process of the injected gases at the ionospheric height is very fast, and the injected gases can lead to a local depletion of electron concentration in the F-region. Furthermore, the plasma 'hole' caused by carbon dioxide is larger, deeper and more durable than that by the hydrogen. (astrophysics and space plasma)

  15. Geomagnetic effects caused by rocket exhaust jets

    Directory of Open Access Journals (Sweden)

    Lipko Yu.V.

    2016-09-01

    Full Text Available In the space experiment Radar–Progress, we have made 33 series of measurements of geomagnetic variations during ignitions of engines of Progress cargo spacecraft in low Earth orbit. We used magneto-measuring complexes, installed at observatories of the Institute of Solar-Terrestrial Physics of Siberian Branch of the Russian Academy of Sciences, and magnetotelluric equipment of a mobile complex. We assumed that engine running can cause geomagnetic disturbances in field tubes crossed by the spacecraft. When analyzing experimental data, we took into account the following space weather factors: solar wind parameters, total daily mid-latitude geomagnetic activity index Kр, geomagnetic auroral electrojet index AE, global geomagnetic activity. The empirical data we obtained indicate that 18 of the 33 series showed geomagnetic variations with various periods.

  16. Unique nuclear thermal rocket engine

    International Nuclear Information System (INIS)

    Culver, D.W.; Rochow, R.

    1993-06-01

    In January, 1992, a new, advanced nuclear thermal rocket engine (NTRE) concept intended for manned missions to the moon and to Mars was introduced (Culver, 1992). This NTRE promises to be both shorter and lighter in weight than conventionally designed engines, because its forward flowing reactor is located within an expansion-deflection rocket nozzle. The concept has matured during the year, and this paper discusses a nearer term version that resolves four open issues identified in the initial concept: (1) the reactor design and cooling scheme simplification while retaining a high pressure power balance option; (2) elimination need for a new, uncooled nozzle throat material suitable for long life application; (3) a practical provision for reactor power control; and (4) use of near-term, long-life turbopumps

  17. Effects of Rocket Exhaust on Lunar Soil Reflectance Properties

    Science.gov (United States)

    Clegg, R. N.; Jolliff, B. L.; Robinson, M. S.; Hapke, B. W.; Plescia, J. B.

    2012-12-01

    The Apollo, Surveyor, and Luna spacecraft descent engine plumes affected the regolith at and surrounding their landing sites. Owing to the lack of rapid weathering processes on the Moon, surface alterations are still visible as photometric anomalies in Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images. These areas are interpreted as disturbance of the regolith by rocket exhaust during descent of the spacecraft, which we refer to as "blast zones" (BZs). The BZs consist of an area of lower reflectance (LR-BZ) compared to the surroundings that extends up to a few meters out from the landers, as well as a broader halo of higher reflectance (HR-BZ) that extends tens to hundreds of meters out from the landers. We use phase-ratio images for each landing site to determine the spatial extent of the disturbed regions and to quantify differences in reflectance and backscattering characteristics within the BZs compared to nearby undisturbed regolith. We also compare the reflectance changes and BZ dimensions at the Apollo sites with those at Luna and Surveyor sites. We seek to determine the effects of rocket exhaust in terms of erosion and particle redistribution, as well as the cause(s) of the reflectance variations, i.e., physical changes at the regolith surface. When approximated as an ellipse, the average Apollo BZ area is ~29,000 m2 (~175 ± 60 m by 200 ± 27 m) which is 10x larger than the average Luna BZ, and over 100x larger than the average Surveyor BZ. Moreover, BZ area scales roughly with lander mass (as a proxy for thrust). The LR-BZs are evident at the Apollo sites, especially where astronaut bioturbation has roughened the soil, leading to a 2-14% reduction in reflectance at ~30° phase. The LR-BZs at the Luna and Surveyor sites are less evident and may be mostly confined to the area below the landers. The average normalized reflectance in the HR-BZs for images with a 30° phase angle is 2-16% higher than in the undisturbed surrounding

  18. 40 CFR 1065.130 - Engine exhaust.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Engine exhaust. 1065.130 Section 1065... ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.130 Engine exhaust. (a) General. Use the exhaust system installed with the engine or one that represents a typical in-use configuration. This...

  19. Measuring Model Rocket Engine Thrust Curves

    Science.gov (United States)

    Penn, Kim; Slaton, William V.

    2010-01-01

    This paper describes a method and setup to quickly and easily measure a model rocket engine's thrust curve using a computer data logger and force probe. Horst describes using Vernier's LabPro and force probe to measure the rocket engine's thrust curve; however, the method of attaching the rocket to the force probe is not discussed. We show how a…

  20. Performances Study of a Hybrid Rocket Engine

    Directory of Open Access Journals (Sweden)

    Adrian-Nicolae BUTURACHE

    2018-06-01

    Full Text Available This paper presents a study which analyses the functioning and performances optimization of a hybrid rocket engine based on gaseous oxygen and polybutadiene polymer (HTPB. Calculations were performed with NASA CEA software in order to obtain the parameters resulted following the combustion process. Using these parameters, the main parameters of the hybrid rocket engine were optimized. Using the calculus previously stated, an experimental rocket engine producing 100 N of thrust was pre-dimensioned, followed by an optimization of the rocket engine as a function of several parameters. Having the geometry and the main parameters of the hybrid rocket engine combustion process, numerical simulations were performed in the CFX – ANSYS commercial software, which allowed visualizing the flow field and the jet expansion. Finally, the analytical calculus was validated through numerical simulations.

  1. A multilayer model to simulate rocket exhaust clouds

    Directory of Open Access Journals (Sweden)

    Davidson Martins Moreira

    2011-01-01

    Full Text Available This paper presents the MSDEF (Modelo Simulador da Dispersão de Efluentes de Foguetes, in Portuguese model, which represents the solution for time-dependent advection-diffusion equation applying the Laplace transform considering the Atmospheric Boundary Layer as a multilayer system. This solution allows a time evolution description of the concentration field emitted from a source during a release lasting time tr , and it takes into account deposition velocity, first-order chemical reaction, gravitational settling, precipitation scavenging, and plume rise effect. This solution is suitable for describing critical events relative to accidental release of toxic, flammable, or explosive substances. A qualitative evaluation of the model to simulate rocket exhaust clouds is showed.

  2. Nitrous Oxide/Paraffin Hybrid Rocket Engines

    Science.gov (United States)

    Zubrin, Robert; Snyder, Gary

    2010-01-01

    Nitrous oxide/paraffin (N2OP) hybrid rocket engines have been invented as alternatives to other rocket engines especially those that burn granular, rubbery solid fuels consisting largely of hydroxyl- terminated polybutadiene (HTPB). Originally intended for use in launching spacecraft, these engines would also be suitable for terrestrial use in rocket-assisted takeoff of small airplanes. The main novel features of these engines are (1) the use of reinforced paraffin as the fuel and (2) the use of nitrous oxide as the oxidizer. Hybrid (solid-fuel/fluid-oxidizer) rocket engines offer advantages of safety and simplicity over fluid-bipropellant (fluid-fuel/fluid-oxidizer) rocket en - gines, but the thrusts of HTPB-based hybrid rocket engines are limited by the low regression rates of the fuel grains. Paraffin used as a solid fuel has a regression rate about 4 times that of HTPB, but pure paraffin fuel grains soften when heated; hence, paraffin fuel grains can, potentially, slump during firing. In a hybrid engine of the present type, the paraffin is molded into a 3-volume-percent graphite sponge or similar carbon matrix, which supports the paraffin against slumping during firing. In addition, because the carbon matrix material burns along with the paraffin, engine performance is not appreciably degraded by use of the matrix.

  3. Yes--This is Rocket Science: MMCs for Liquid Rocket Engines

    National Research Council Canada - National Science Library

    Shelley, J

    2001-01-01

    The Air Force's Integrated High-Payoff Rocket Propulsion Technologies (IHPRPT) Program has established aggressive goals for both improved performance and reduced cost of rocket engines and components...

  4. MHD thrust vectoring of a rocket engine

    Science.gov (United States)

    Labaune, Julien; Packan, Denis; Tholin, Fabien; Chemartin, Laurent; Stillace, Thierry; Masson, Frederic

    2016-09-01

    In this work, the possibility to use MagnetoHydroDynamics (MHD) to vectorize the thrust of a solid propellant rocket engine exhaust is investigated. Using a magnetic field for vectoring offers a mass gain and a reusability advantage compared to standard gimbaled, elastomer-joint systems. Analytical and numerical models were used to evaluate the flow deviation with a 1 Tesla magnetic field inside the nozzle. The fluid flow in the resistive MHD approximation is calculated using the KRONOS code from ONERA, coupling the hypersonic CFD platform CEDRE and the electrical code SATURNE from EDF. A critical parameter of these simulations is the electrical conductivity, which was evaluated using a set of equilibrium calculations with 25 species. Two models were used: local thermodynamic equilibrium and frozen flow. In both cases, chlorine captures a large fraction of free electrons, limiting the electrical conductivity to a value inadequate for thrust vectoring applications. However, when using chlorine-free propergols with 1% in mass of alkali, an MHD thrust vectoring of several degrees was obtained.

  5. Rocket propulsion elements - An introduction to the engineering of rockets (6th revised and enlarged edition)

    Science.gov (United States)

    Sutton, George P.

    The subject of rocket propulsion is treated with emphasis on the basic technology, performance, and design rationale. Attention is given to definitions and fundamentals, nozzle theory and thermodynamic relations, heat transfer, flight performance, chemical rocket propellant performance analysis, and liquid propellant rocket engine fundamentals. The discussion also covers solid propellant rocket fundamentals, hybrid propellant rockets, thrust vector control, selection of rocket propulsion systems, electric propulsion, and rocket testing.

  6. Exhaust system of an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-04

    A catalytic converter system for internal combustion engines is described that includes a means to maintain the catalyst temperature within a predetermined range for the efficient reduction of nitrogen oxides in the exhaust gas. Upstream of the catalytic converter, the exhaust pipe is encased in a structure such that a space is provided for the flow of a coolant around the exhaust pipe in response to the sensed catalytic temperature. A coolant control valve is actuated in response to the temperature sensor.

  7. System for measuring engine exhaust constituents

    International Nuclear Information System (INIS)

    Carduner, K.R.; Colvin, A.D.; Leong, D.Y.W.

    1992-01-01

    This patent describes a system for measuring an automotive engine exhaust constituent. It comprises: a meter for determining the mass of air flowing through the engine and for generating an engine airflow signal corresponding to the airflow; sample handling apparatus; diluent adding means; processor means. This patent also describes a method for using an analyzer to determine the amount of lubricating oil consumed by an automotive engine. It comprises: determining the amount of sulfur dioxide within the room air being drawn into the engine; maintaining a constant total flow comprised of a constant fraction of the engine's exhaust gas and a diluent gas through the analyzer, while: determining the amount of sulfur dioxide contained within the engine's exhaust, determining the amount of sulfur dioxide contained within the engine's exhaust, while operating the engine on room air; determining an efficiency factor for the analyzer; and using the efficiency factor and the concentration of sulfur in the engine oil and the amounts of sulfur dioxide determined in steps a and d to determine the amount of lubrication oil leaving the engine through its exhaust

  8. Rocket Based Combined Cycle (RBCC) engine inlet

    Science.gov (United States)

    2004-01-01

    Pictured is a component of the Rocket Based Combined Cycle (RBCC) engine. This engine was designed to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsion systems and ultimately a Single Stage to Orbit (SSTO) air breathing propulsion system.

  9. Additive Manufacturing for Affordable Rocket Engines

    Science.gov (United States)

    West, Brian; Robertson, Elizabeth; Osborne, Robin; Calvert, Marty

    2016-01-01

    Additive manufacturing (also known as 3D printing) technology has the potential to drastically reduce costs and lead times associated with the development of complex liquid rocket engine systems. NASA is using 3D printing to manufacture rocket engine components including augmented spark igniters, injectors, turbopumps, and valves. NASA is advancing the process to certify these components for flight. Success Story: MSFC has been developing rocket 3D-printing technology using the Selective Laser Melting (SLM) process. Over the last several years, NASA has built and tested several injectors and combustion chambers. Recently, MSFC has 3D printed an augmented spark igniter for potential use the RS-25 engines that will be used on the Space Launch System. The new design is expected to reduce the cost of the igniter by a factor of four. MSFC has also 3D printed and tested a liquid hydrogen turbopump for potential use on an Upper Stage Engine. Additive manufacturing of the turbopump resulted in a 45% part count reduction. To understanding how the 3D printed parts perform and to certify them for flight, MSFC built a breadboard liquid rocket engine using additive manufactured components including injectors, turbomachinery, and valves. The liquid rocket engine was tested seven times in 2016 using liquid oxygen and liquid hydrogen. In addition to exposing the hardware to harsh environments, engineers learned to design for the new manufacturing technique, taking advantage of its capabilities and gaining awareness of its limitations. Benefit: The 3D-printing technology promises reduced cost and schedule for rocket engines. Cost is a function of complexity, and the most complicated features provide the largest opportunities for cost reductions. This is especially true where brazes or welds can be eliminated. The drastic reduction in part count achievable with 3D printing creates a waterfall effect that reduces the number of processes and drawings, decreases the amount of touch

  10. Design and Evaluation of a Turbojet Exhaust Simulator, Utilizing a Solid-Propellant Rocket Motor, for use in Free-Flight Aerodynamic Research Models

    Science.gov (United States)

    deMoraes, Carlos A.; Hagginbothom, William K., Jr.; Falanga, Ralph A.

    1954-01-01

    A method has been developed for modifying a rocket motor so that its exhaust characteristics simulate those of a turbojet engine. The analysis necessary to the design is presented along with tests from which the designs are evaluated. Simulation was found to be best if the exhaust characteristics to be duplicated were those of a turbojet engine at high altitudes and with the afterburner operative.

  11. Two phase exhaust for internal combustion engine

    Science.gov (United States)

    Vuk, Carl T [Denver, IA

    2011-11-29

    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  12. Development of nuclear rocket engine technology

    International Nuclear Information System (INIS)

    Gunn, S.V.

    1989-01-01

    Research sponsored by the Atomic Energy Commission, the USAF, and NASA (later on) in the area of nuclear rocket propulsion is discussed. It was found that a graphite reactor, loaded with highly concentrated Uranium 235, can be used to heat high pressure liquid hydrogen to temperatures of about 4500 R, and to expand the hydrogen through a high expansion ratio rocket nozzle assembly. The results of 20 reactor tests conducted at the Nevada Test Site between July 1959 and June 1969 are analyzed. On the basis of these results, the feasibility of solid graphite reactor/nuclear rocket engines is revealed. It is maintained that this technology will support future space propulsion requirements, using liquid hydrogen as the propellant, for thrust requirements ranging from 25,000 lbs to 250,000 lbs, with vacuum specific impulses of at least 850 sec and with full engine throttle capability. 12 refs

  13. Exhaust gas afterburner for internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Haertel, G

    1977-05-12

    The invention pertains to an exhaust gas afterburner for internal combustion engines, with an auxiliary fuel device arranged upstream from the afterburner proper and controlled by the rotational speed of the engine, which is additionally controlled by an oxygen or carbon monoxide sensor. The catalytic part of the afterburner, together with a rotochamber, is a separate unit.

  14. Hybrid rocket engine, theoretical model and experiment

    Science.gov (United States)

    Chelaru, Teodor-Viorel; Mingireanu, Florin

    2011-06-01

    The purpose of this paper is to build a theoretical model for the hybrid rocket engine/motor and to validate it using experimental results. The work approaches the main problems of the hybrid motor: the scalability, the stability/controllability of the operating parameters and the increasing of the solid fuel regression rate. At first, we focus on theoretical models for hybrid rocket motor and compare the results with already available experimental data from various research groups. A primary computation model is presented together with results from a numerical algorithm based on a computational model. We present theoretical predictions for several commercial hybrid rocket motors, having different scales and compare them with experimental measurements of those hybrid rocket motors. Next the paper focuses on tribrid rocket motor concept, which by supplementary liquid fuel injection can improve the thrust controllability. A complementary computation model is also presented to estimate regression rate increase of solid fuel doped with oxidizer. Finally, the stability of the hybrid rocket motor is investigated using Liapunov theory. Stability coefficients obtained are dependent on burning parameters while the stability and command matrixes are identified. The paper presents thoroughly the input data of the model, which ensures the reproducibility of the numerical results by independent researchers.

  15. AJ26 rocket engine testing news briefing

    Science.gov (United States)

    2010-01-01

    NASA's John C. Stennis Space Center Director Gene Goldman (center) stands in front of a 'pathfinder' rocket engine with Orbital Sciences Corp. President and Chief Operating Officer J.R. Thompson (left) and Aerojet President Scott Seymour during a Feb. 24 news briefing at the south Mississippi facility. The leaders appeared together to announce a partnership for testing Aerojet AJ26 rocket engines at Stennis. The engines will be used to power Orbital's Taurus II space vehicles to provide commercial cargo transportation missions to the International Space Station for NASA. During the event, the Stennis partnership with Orbital was cited as an example of the new direction of NASA to work with commercial interests for space travel and transport.

  16. Nuclear thermal rocket engine operation and control

    International Nuclear Information System (INIS)

    Gunn, S.V.; Savoie, M.T.; Hundal, R.

    1993-06-01

    The operation of a typical Rover/Nerva-derived nuclear thermal rocket (NTR) engine is characterized and the control requirements of the NTR are defined. A rationale for the selection of a candidate diverse redundant NTR engine control system is presented and the projected component operating requirements are related to the state of the art of candidate components and subsystems. The projected operational capabilities of the candidate system are delineated for the startup, full-thrust, shutdown, and decay heat removal phases of the engine operation. 9 refs

  17. Ionospheric effects of rocket exhaust products (HEAO-C, Skylab and SPS-HLLV)

    International Nuclear Information System (INIS)

    Zinn, J.; Sutherland, D.; Stone, S.N.; Duncan, L.M.; Behnke, R.

    1980-10-01

    This paper reviews the current state of our understanding of the problem of ionospheric F-layer depletions produced by chemical effects of the exhaust gases from large rockets, with particular emphasis on the Heavy Lift Launch Vehicles (HLLV) proposed for use in the construction of solar power satellites. The currently planned HLLV flight profile calls for main second-stage propulsion confined to altitudes below 124 km, and a brief orbit-circularization maneuver at apogee. The second-stage engines deposit 9 x 10 31 H 2 O and H 2 molecules between 56 and 124 km. Model computations show that they diffuse gradually into the ionospheric F region, where they lead to weak but widespread and persistent depletions of ionization and continuous production of H atoms. The orbit-circularization burn deposits 9 x 10 29 exhaust molecules at about 480-km altitude. These react rapidly with the F2 region 0 + ions, leading to a substantial (factor-of-three) reduction in plasma density, which extends over a 1000- by 2000-km region and persists for four to five hours. Also described are experimental airglow and incoherent-scatter radar measurements performed in conjunction with the 1979 launch of satellite HEAO-C, together with prelaunch and post-launch computations of the ionospheric effects. Several improvements in the model have been driven by the experimental observations. The computer model is described in some detail

  18. Aircraft Piston Engine Exhaust Emission Symposium

    Science.gov (United States)

    1976-01-01

    A 2-day symposium on the reduction of exhaust emissions from aircraft piston engines was held on September 14 and 15, 1976, at the Lewis Research Center in Cleveland, Ohio. Papers were presented by both government organizations and the general aviation industry on the status of government contracts, emission measurement problems, data reduction procedures, flight testing, and emission reduction techniques.

  19. Rocket Based Combined Cycle (RBCC) Engine

    Science.gov (United States)

    2004-01-01

    Pictured is an artist's concept of the Rocket Based Combined Cycle (RBCC) launch. The RBCC's overall objective is to provide a technology test bed to investigate critical technologies associated with opperational usage of these engines. The program will focus on near term technologies that can be leveraged to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsions systems and ultimately a Single Stage To Orbit (SSTO) air breathing propulsion system.

  20. Ignition and Flame Stabilization of a Strut-Jet RBCC Combustor with Small Rocket Exhaust

    Directory of Open Access Journals (Sweden)

    Jichao Hu

    2014-01-01

    Full Text Available A Rocket Based Combined Cycle combustor model is tested at a ground direct connected rig to investigate the flame holding characteristics with a small rocket exhaust using liquid kerosene. The total temperature and the Mach number of the vitiated air flow, at exit of the nozzle are 1505 K and 2.6, respectively. The rocket base is embedded in a fuel injecting strut and mounted in the center of the combustor. The wall of the combustor is flush, without any reward step or cavity, so the strut-jet is used to make sure of the flame stabilization of the second combustion. Mass flow rate of the kerosene and oxygen injected into the rocket is set to be a small value, below 10% of the total fuel when the equivalence ratio of the second combustion is 1. The experiment has generated two different kinds of rocket exhaust: fuel rich and pure oxygen. Experiment result has shown that, with a relative small total mass flow rate of the rocket, the fuel rich rocket plume is not suitable for ignition and flame stabilization, while an oxygen plume condition is suitable. Then the paper conducts a series of experiments to investigate the combustion characteristics under this oxygen pilot method and found that the flame stabilization characteristics are different at different combustion modes.

  1. 46 CFR 182.430 - Engine exhaust pipe installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Engine exhaust pipe installation. 182.430 Section 182... 100 GROSS TONS) MACHINERY INSTALLATION Specific Machinery Requirements § 182.430 Engine exhaust pipe... equipment might come in contact with an exhaust pipe. (b) Exhaust gas must not leak from the piping or any...

  2. 46 CFR 119.430 - Engine exhaust pipe installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Engine exhaust pipe installation. 119.430 Section 119... INSTALLATION Specific Machinery Requirements § 119.430 Engine exhaust pipe installation. (a) The design of all... an exhaust pipe. (b) Exhaust gas must not leak from the piping or any connections. The piping must be...

  3. Software for Collaborative Engineering of Launch Rockets

    Science.gov (United States)

    Stanley, Thomas Troy

    2003-01-01

    The Rocket Evaluation and Cost Integration for Propulsion and Engineering software enables collaborative computing with automated exchange of information in the design and analysis of launch rockets and other complex systems. RECIPE can interact with and incorporate a variety of programs, including legacy codes, that model aspects of a system from the perspectives of different technological disciplines (e.g., aerodynamics, structures, propulsion, trajectory, aeroheating, controls, and operations) and that are used by different engineers on different computers running different operating systems. RECIPE consists mainly of (1) ISCRM a file-transfer subprogram that makes it possible for legacy codes executed in their original operating systems on their original computers to exchange data and (2) CONES an easy-to-use filewrapper subprogram that enables the integration of legacy codes. RECIPE provides a tightly integrated conceptual framework that emphasizes connectivity among the programs used by the collaborators, linking these programs in a manner that provides some configuration control while facilitating collaborative engineering tradeoff studies, including design to cost studies. In comparison with prior collaborative-engineering schemes, one based on the use of RECIPE enables fewer engineers to do more in less time.

  4. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  5. Exhaust gas recirculation system for an internal combustion engine

    Science.gov (United States)

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  6. Axisymmetric Numerical Modeling of Pulse Detonation Rocket Engines

    Science.gov (United States)

    Morris, Christopher I.

    2005-01-01

    Pulse detonation rocket engines (PDREs) have generated research interest in recent years as a chemical propulsion system potentially offering improved performance and reduced complexity compared to conventional rocket engines. The detonative mode of combustion employed by these devices offers a thermodynamic advantage over the constant-pressure deflagrative combustion mode used in conventional rocket engines and gas turbines. However, while this theoretical advantage has spurred considerable interest in building PDRE devices, the unsteady blowdown process intrinsic to the PDRE has made realistic estimates of the actual propulsive performance problematic. The recent review article by Kailasanath highlights some of the progress that has been made in comparing the available experimental measurements with analytical and numerical models. In recent work by the author, a quasi-one-dimensional, finite rate chemistry CFD model was utilized to study the gasdynamics and performance characteristics of PDREs over a range of blowdown pressure ratios from 1-1000. Models of this type are computationally inexpensive, and enable first-order parametric studies of the effect of several nozzle and extension geometries on PDRE performance over a wide range of conditions. However, the quasi-one-dimensional approach is limited in that it cannot properly capture the multidimensional blast wave and flow expansion downstream of the PDRE, nor can it resolve nozzle flow separation if present. Moreover, the previous work was limited to single-pulse calculations. In this paper, an axisymmetric finite rate chemistry model is described and utilized to study these issues in greater detail. Example Mach number contour plots showing the multidimensional blast wave and nozzle exhaust plume are shown. The performance results are compared with the quasi-one-dimensional results from the previous paper. Both Euler and Navier-Stokes solutions are calculated in order to determine the effect of viscous

  7. Rocket Engine Innovations Advance Clean Energy

    Science.gov (United States)

    2012-01-01

    During launch countdown, at approximately T-7 seconds, the Space Shuttle Main Engines (SSMEs) roar to life. When the controllers indicate normal operation, the solid rocket boosters ignite and the shuttle blasts off. Initially, the SSMEs throttle down to reduce stress during the period of maximum dynamic pressure, but soon after, they throttle up to propel the orbiter to 17,500 miles per hour. In just under 9 minutes, the three SSMEs burn over 1.6 million pounds of propellant, and temperatures inside the main combustion chamber reach 6,000 F. To cool the engines, liquid hydrogen circulates through miles of tubing at -423 F. From 1981to 2011, the Space Shuttle fleet carried crew and cargo into orbit to perform a myriad of unprecedented tasks. After 30 years and 135 missions, the feat of engineering known as the SSME boasted a 100-percent flight success rate.

  8. Reusable Rocket Engine Turbopump Health Management System

    Science.gov (United States)

    Surko, Pamela

    1994-01-01

    A health monitoring expert system software architecture has been developed to support condition-based health monitoring of rocket engines. Its first application is in the diagnosis decisions relating to the health of the high pressure oxidizer turbopump (HPOTP) of Space Shuttle Main Engine (SSME). The post test diagnostic system runs off-line, using as input the data recorded from hundreds of sensors, each running typically at rates of 25, 50, or .1 Hz. The system is invoked after a test has been completed, and produces an analysis and an organized graphical presentation of the data with important effects highlighted. The overall expert system architecture has been developed and documented so that expert modules analyzing other line replaceable units may easily be added. The architecture emphasizes modularity, reusability, and open system interfaces so that it may be used to analyze other engines as well.

  9. Numerical investigations of hybrid rocket engines

    Science.gov (United States)

    Betelin, V. B.; Kushnirenko, A. G.; Smirnov, N. N.; Nikitin, V. F.; Tyurenkova, V. V.; Stamov, L. I.

    2018-03-01

    Paper presents the results of numerical studies of hybrid rocket engines operating cycle including unsteady-state transition stage. A mathematical model is developed accounting for the peculiarities of diffusion combustion of fuel in the flow of oxidant, which is composed of oxygen-nitrogen mixture. Three dimensional unsteady-state simulations of chemically reacting gas mixture above thermochemically destructing surface are performed. The results show that the diffusion combustion brings to strongly non-uniform fuel mass regression rate in the flow direction. Diffusive deceleration of chemical reaction brings to the decrease of fuel regression rate in the longitudinal direction.

  10. 46 CFR 119.425 - Engine exhaust cooling.

    Science.gov (United States)

    2010-10-01

    ..., all engine exhaust pipes must be water cooled. (1) Vertical dry exhaust pipes are permissible if installed in compliance with §§ 116.405(c) and 116.970 of this chapter. (2) Horizontal dry exhaust pipes are...) They are installed in compliance with §§ 116.405(c) and 116.970 of this chapter. (b) The exhaust pipe...

  11. Observation and simulation of the ionosphere disturbance waves triggered by rocket exhausts

    Science.gov (United States)

    Lin, Charles C. H.; Chen, Chia-Hung; Matsumura, Mitsuru; Lin, Jia-Ting; Kakinami, Yoshihiro

    2017-08-01

    Observations and theoretical modeling of the ionospheric disturbance waves generated by rocket launches are investigated. During the rocket passage, time rate change of total electron content (rTEC) enhancement with the V-shape shock wave signature is commonly observed, followed by acoustic wave disturbances and region of negative rTEC centered along the trajectory. Ten to fifteen min after the rocket passage, delayed disturbance waves appeared and propagated along direction normal to the V-shape wavefronts. These observation features appeared most prominently in the 2016 North Korea rocket launch showing a very distinct V-shape rTEC enhancement over enormous areas along the southeast flight trajectory despite that it was also appeared in the 2009 North Korea rocket launch with the eastward flight trajectory. Numerical simulations using the physical-based nonlinear and nonhydrostatic coupled model of neutral atmosphere and ionosphere reproduce promised results in qualitative agreement with the characteristics of ionospheric disturbance waves observed in the 2009 event by considering the released energy of the rocket exhaust as the disturbance source. Simulations reproduce the shock wave signature of electron density enhancement, acoustic wave disturbances, the electron density depletion due to the rocket-induced pressure bulge, and the delayed disturbance waves. The pressure bulge results in outward neutral wind flows carrying neutrals and plasma away from it and leading to electron density depletions. Simulations further show, for the first time, that the delayed disturbance waves are produced by the surface reflection of the earlier arrival acoustic wave disturbances.

  12. IR radiation characteristics of rocket exhaust plumes under varying motor operating conditions

    Directory of Open Access Journals (Sweden)

    Qinglin NIU

    2017-06-01

    Full Text Available The infrared (IR irradiance signature from rocket motor exhaust plumes is closely related to motor type, propellant composition, burn time, rocket geometry, chamber parameters and flight conditions. In this paper, an infrared signature analysis tool (IRSAT was developed to understand the spectral characteristics of exhaust plumes in detail. Through a finite volume technique, flow field properties were obtained through the solution of axisymmetric Navier-Stokes equations with the Reynolds-averaged approach. A refined 13-species, 30-reaction chemistry scheme was used for combustion effects and a k-ε-Rt turbulence model for entrainment effects. Using flowfield properties as input data, the spectrum was integrated with a line of sight (LOS method based on a single line group (SLG model with Curtis-Godson approximation. The model correctly predicted spectral distribution in the wavelengths of 1.50–5.50 μm and had good agreement for its location with imaging spectrometer data. The IRSAT was then applied to discuss the effects of three operating conditions on IR signatures: (a afterburning; (b chamber pressure from ignition to cutoff; and (c minor changes in the ratio of hydroxyl-terminated polybutadiene (HTPB binder to ammonium perchlorate (AP oxidizer in propellant. Results show that afterburning effects can increase the size and shape of radiance images with enhancement of radiation intensity up to 40%. Also, the total IR irradiance in different bands can be characterized by a non-dimensional chamber pressure trace in which the maximum discrepancy is less than 13% during ignition and engine cutoff. An increase of chamber pressure can lead to more distinct diamonds, whose distance intervals are extended, and the position of the first diamond moving backwards. In addition, an increase in HTPB/AP causes a significant jump in spectral intensity. The incremental rates of radiance intensity integrated in each band are linear with the increase of HTPB

  13. Developments in REDES: The Rocket Engine Design Expert System

    Science.gov (United States)

    Davidian, Kenneth O.

    1990-01-01

    The Rocket Engine Design Expert System (REDES) was developed at NASA-Lewis to collect, automate, and perpetuate the existing expertise of performing a comprehensive rocket engine analysis and design. Currently, REDES uses the rigorous JANNAF methodology to analyze the performance of the thrust chamber and perform computational studies of liquid rocket engine problems. The following computer codes were included in REDES: a gas properties program named GASP; a nozzle design program named RAO; a regenerative cooling channel performance evaluation code named RTE; and the JANNAF standard liquid rocket engine performance prediction code TDK (including performance evaluation modules ODE, ODK, TDE, TDK, and BLM). Computational analyses are being conducted by REDES to provide solutions to liquid rocket engine thrust chamber problems. REDES was built in the Knowledge Engineering Environment (KEE) expert system shell and runs on a Sun 4/110 computer.

  14. Optical measurements in rocket engine liquid sprays

    Science.gov (United States)

    Feikema, Douglas A.

    1994-01-01

    The performance of liquid propellant rocket engines is dependent upon many elements of the entire system. One of the most fundamental and most critical is the performance of the injector elements. Their characterization is an important part of the development of combustion devices. Optical measurements within these environments have proven to be invaluable tools in quantifying the physical environment of two phase flows. The effort reported herein involves the measurement of drop velocity, drop size, and most importantly mass flux using Phase-Doppler Particle Anemometry within a spray generated by a single swirl injector element operating in atmospheric pressure conditions. The mass flux has been determined and validated by mechanical patternation methods and by profile integration of the mass flux.

  15. Air flow quality analysis of modenas engine exhaust system

    Science.gov (United States)

    Shahriman A., B.; Mohamad Syafiq A., K.; Hashim, M. S. M.; Razlan, Zuradzman M.; Khairunizam W. A., N.; Hazry, D.; Afendi, Mohd; Daud, R.; Rahman, M. D. Tasyrif Abdul; Cheng, E. M.; Zaaba, S. K.

    2017-09-01

    The simulation process being conducted to determine the air flow effect between the original exhaust system and modified exhaust system. The simulations are conducted to investigate the flow distribution of exhaust gases that will affect the performance of the engine. The back flow pressure in the original exhaust system is predicted toward this simulation. The design modification to the exhaust port, exhaust pipe, and exhaust muffler has been done during this simulation to reduce the back flow effect. The new designs are introduced by enlarging the diameter of the exhaust port, enlarge the diameter of the exhaust pipe and created new design for the exhaust muffler. Based on the result obtained, there the pulsating flow form at the original exhaust port that will increase the velocity and resulting the back pressure occur. The result for new design of exhaust port, the velocity is lower at the valve guide in the exhaust port. New design muffler shows that the streamline of the exhaust flow move smoothly compare to the original muffler. It is proved by using the modification exhaust system, the back pressure are reduced and the engine performance can be improve.

  16. Using Lunar Module Shadows To Scale the Effects of Rocket Exhaust Plumes

    Science.gov (United States)

    2008-01-01

    Excavating granular materials beneath a vertical jet of gas involves several physical mechanisms. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. We performed a series of experiments and simulations (Figure 1) to provide a detailed view of the complex gas-soil interactions. Measurements taken from the Apollo lunar landing videos (Figure 2) and from photographs of the resulting terrain helped demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a fundamental level to support the ongoing design of higher fidelity numerical simulations and larger-scale experiments. These are needed to enable future lunar exploration wherein multiple hardware assets will be placed on the Moon within short distances of one another. The high-velocity spray of soil from the landing spacecraft must be accurately predicted and controlled or it could erode the surfaces of nearby hardware. This analysis indicated that the lunar dust is ejected at an angle of less than 3 degrees above the surface, the results of which can be mitigated by a modest berm of lunar soil. These results assume that future lunar landers will use a single engine. The analysis would need to be adjusted for a multiengine lander. Figure 3 is a detailed schematic of the Lunar Module camera calibration math model. In this chart, formulas relating the known quantities, such as sun angle and Lunar Module dimensions, to the unknown quantities are depicted. The camera angle PSI is determined by measurement of the imaged aspect ratio of a crater, where the crater is assumed to be circular. The final solution is the determination of the camera calibration factor, alpha. Figure 4 is a detailed schematic of the dust angle math model, which again relates known to unknown parameters. The known parameters now include the camera calibration factor and Lunar Module dimensions. The final computation is the ejected

  17. Exhaust gas recirculation apparatus for internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Shigemori, M; Eguchi, N

    1975-01-07

    An exhaust gas recirculation device to reduce nitrogen oxides emission from internal combustion engines is described. The recirculation is achieved by employing a tube connecting between the exhaust pipe and intake tube. A throttle valve is installed within the exhaust pipe between the muffler and recirculation tube, and regulated by exhaust gas temperature. Whenever the gas temperature is high, the valve closes and increases the gas flow to the intake tube. A temperature sensor is installed within the exhaust pipe and controls a solenoid or magnetic air valve linking to the throttle valve through a relay. The recirculation tube can be cooled by a fan to improve the engine power.

  18. Engine with exhaust gas recirculation system and variable geometry turbocharger

    Science.gov (United States)

    Keating, Edward J.

    2015-11-03

    An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.

  19. Three-Dimensional Numerical Analysis of LOX/Kerosene Engine Exhaust Plume Flow Field Characteristics

    Directory of Open Access Journals (Sweden)

    Hong-hua Cai

    2017-01-01

    Full Text Available Aiming at calculating and studying the flow field characteristics of engine exhaust plume and comparative analyzing the effects of different chemical reaction mechanisms on the engine exhaust plume flow field characteristics, a method considering fully the combustion state influence is put forward, which is applied to exhaust plume flow field calculation of multinozzle engine. On this basis, a three-dimensional numerical analysis of the effects of different chemical reaction mechanisms on LOX/kerosene engine exhaust plume flow field characteristics was carried out. It is found that multistep chemical reaction can accurately describe the combustion process in the LOX/kerosene engine, the average chamber pressure from the calculation is 4.63% greater than that of the test, and the average chamber temperature from the calculation is 3.34% greater than that from the thermodynamic calculation. The exhaust plumes of single nozzle and double nozzle calculated using the global chemical reaction are longer than those using the multistep chemical reaction; the highest temperature and the highest velocity on the plume axis calculated using the former are greater than that using the latter. The important influence of chemical reaction mechanism must be considered in the study of the fixing structure of double nozzle engine on the rocket body.

  20. Telemetry Boards Interpret Rocket, Airplane Engine Data

    Science.gov (United States)

    2009-01-01

    For all the data gathered by the space shuttle while in orbit, NASA engineers are just as concerned about the information it generates on the ground. From the moment the shuttle s wheels touch the runway to the break of its electrical umbilical cord at 0.4 seconds before its next launch, sensors feed streams of data about the status of the vehicle and its various systems to Kennedy Space Center s shuttle crews. Even while the shuttle orbiter is refitted in Kennedy s orbiter processing facility, engineers constantly monitor everything from power levels to the testing of the mechanical arm in the orbiter s payload bay. On the launch pad and up until liftoff, the Launch Control Center, attached to the large Vehicle Assembly Building, screens all of the shuttle s vital data. (Once the shuttle clears its launch tower, this responsibility shifts to Mission Control at Johnson Space Center, with Kennedy in a backup role.) Ground systems for satellite launches also generate significant amounts of data. At Cape Canaveral Air Force Station, across the Banana River from Kennedy s location on Merritt Island, Florida, NASA rockets carrying precious satellite payloads into space flood the Launch Vehicle Data Center with sensor information on temperature, speed, trajectory, and vibration. The remote measurement and transmission of systems data called telemetry is essential to ensuring the safe and successful launch of the Agency s space missions. When a launch is unsuccessful, as it was for this year s Orbiting Carbon Observatory satellite, telemetry data also provides valuable clues as to what went wrong and how to remedy any problems for future attempts. All of this information is streamed from sensors in the form of binary code: strings of ones and zeros. One small company has partnered with NASA to provide technology that renders raw telemetry data intelligible not only for Agency engineers, but also for those in the private sector.

  1. Combustion and Magnetohydrodynamic Processes in Advanced Pulse Detonation Rocket Engines

    Science.gov (United States)

    Cole, Lord Kahil

    A number of promising alternative rocket propulsion concepts have been developed over the past two decades that take advantage of unsteady combustion waves in order to produce thrust. These concepts include the Pulse Detonation Rocket Engine (PDRE), in which repetitive ignition, propagation, and reflection of detonations and shocks can create a high pressure chamber from which gases may be exhausted in a controlled manner. The Pulse Detonation Rocket Induced Magnetohydrodynamic Ejector (PDRIME) is a modification of the basic PDRE concept, developed by Cambier (1998), which has the potential for performance improvements based on magnetohydrodynamic (MHD) thrust augmentation. The PDRIME has the advantage of both low combustion chamber seeding pressure, per the PDRE concept, and efficient energy distribution in the system, per the rocket-induced MHD ejector (RIME) concept of Cole, et al. (1995). In the initial part of this thesis, we explore flow and performance characteristics of different configurations of the PDRIME, assuming quasi-one-dimensional transient flow and global representations of the effects of MHD phenomena on the gas dynamics. By utilizing high-order accurate solvers, we thus are able to investigate the fundamental physical processes associated with the PDRIME and PDRE concepts and identify potentially promising operating regimes. In the second part of this investigation, the detailed coupling of detonations and electric and magnetic fields are explored. First, a one-dimensional spark-ignited detonation with complex reaction kinetics is fully evaluated and the mechanisms for the different instabilities are analyzed. It is found that complex kinetics in addition to sufficient spatial resolution are required to be able to quantify high frequency as well as low frequency detonation instability modes. Armed with this quantitative understanding, we then examine the interaction of a propagating detonation and the applied MHD, both in one-dimensional and two

  2. Estimates of the radiation environment for a nuclear rocket engine

    International Nuclear Information System (INIS)

    Courtney, J.C.; Manohara, H.M.; Williams, M.L.

    1992-01-01

    Ambitious missions in deep space, such as manned expeditions to Mars, require nuclear propulsion if they are to be accomplished in a reasonable length of time. Current technology is adequate to support the use of nuclear fission as a source of energy for propulsion; however, problems associated with neutrons and gammas leaking from the rocket engine must be addressed. Before manned or unmanned space flights are attempted, an extensive ground test program on the rocket engine must be completed. This paper compares estimated radiation levels and nuclear heating rates in and around the rocket engine for both a ground test and space environments

  3. Lightweight Exhaust Manifold and Exhaust Pipe Ducting for Internal Combustion Engines

    Science.gov (United States)

    Northam, G. Burton (Inventor); Ransone, Philip O. (Inventor); Rivers, H. Kevin (Inventor)

    1999-01-01

    An improved exhaust system for an internal combustion gasoline-and/or diesel-fueled engine includes an engine exhaust manifold which has been fabricated from carbon- carbon composite materials in operative association with an exhaust pipe ducting which has been fabricated from carbon-carbon composite materials. When compared to conventional steel. cast iron. or ceramic-lined iron paris. the use of carbon-carbon composite exhaust-gas manifolds and exhaust pipe ducting reduces the overall weight of the engine. which allows for improved acceleration and fuel efficiency: permits operation at higher temperatures without a loss of strength: reduces the "through-the wall" heat loss, which increases engine cycle and turbocharger efficiency and ensures faster "light-off" of catalytic converters: and, with an optional thermal reactor, reduces emission of major pollutants, i.e. hydrocarbons and carbon monoxide.

  4. Propellant Flow Actuated Piezoelectric Rocket Engine Igniter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spark ignition of a bi-propellant rocket engine is a classic, proven, and generally reliable process. However, timing can be critical, and the control logic,...

  5. Distributed Rocket Engine Testing Health Monitoring System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The on-ground and Distributed Rocket Engine Testing Health Monitoring System (DiRETHMS) provides a system architecture and software tools for performing diagnostics...

  6. Distributed Rocket Engine Testing Health Monitoring System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Leveraging the Phase I achievements of the Distributed Rocket Engine Testing Health Monitoring System (DiRETHMS) including its software toolsets and system building...

  7. Advanced Vortex Hybrid Rocket Engine (AVHRE), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop a unique Advanced Vortex Hybrid Rocket Engine (AVHRE) to achieve a safe, highly-reliable, low-cost and uniquely versatile propulsion...

  8. Advanced Vortex Hybrid Rocket Engine (AVHRE), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Orbital Technologies Corporation (ORBITEC) proposes to develop a unique Advanced Vortex Hybrid Rocket Engine (AVHRE) to achieve a highly-reliable, low-cost and...

  9. Current status of rocket developments in universities -development of a small hybrid rocket with a swirling oxidizer flow type engine

    OpenAIRE

    Yuasa, Saburo; Kitagawa, Koki

    2005-01-01

    To develop an experimental small hybrid rocket with a swirling gaseous oxygen flow type engine, we made a flight model engine. Burning tests of the engine showed that a maximum thrust of 692 N and a specific impulse of 263 s (at sea level) were achieved. We designed a small hybrid rocket with this engine. The rocket measured 1.8 m in length and 15.4 kg in mass. To confirm the flight stability of the rocket, wind tunnel tests using a 112-scale model of the rocket and simulations of the flight ...

  10. The 4D-var Estimation of North Korean Rocket Exhaust Emissions Into the Ionosphere

    Science.gov (United States)

    Ssessanga, Nicholas; Kim, Yong Ha; Choi, Byungyu; Chung, Jong-Kyun

    2018-03-01

    We have developed a four-dimensional variation data assimilation technique (4D-var) and utilized it to reconstruct three-dimensional images of the ionospheric hole created during Kwangmyongsong-4 rocket launch. Kwangmyongsong-4 was launched southward from North Korea Sohae space center (124.7°E, 39.6°N) at 00:30 UT on 7 February 2016. The data assimilated were Global Positioning System total electron content from the South Korean Global Positioning System-receiver network. Due to lack of publicized information about Kwangmyongsong-4, the rocket was assumed to inherit its technology from previous launches (Taepodong-2). The created ionospheric hole was assumed to be made by neutral molecules, water (H2O) and hydrogen (H2), deposited in exhaust plumes. The dispersion model was developed based on advection and diffusion equation, and a simple asymmetric diffusion model assumed. From the analysis, using the adjoint technique, we estimated an ionospheric hole with the largest depletion existing around 6-7 min after launch and gradually recovering within 30 min. These results are in agreement with temporal total electron content analyses of the same event from previous studies. Furthermore, Kwangmyongsong-4 second stage exhaust emissions were estimated as 1.9 × 1026 s-1 of which 40% was H2 and the rest H2O.

  11. Development of Kabila rocket: A radioisotope heated thermionic plasma rocket engine

    Directory of Open Access Journals (Sweden)

    Kalomba Mboyi

    2015-04-01

    Full Text Available A new type of plasma rocket engine, the Kabila rocket, using a radioisotope heated thermionic heating chamber instead of a conventional combustion chamber or catalyst bed is introduced and it achieves specific impulses similar to the ones of conventional solid and bipropellant rockets. Curium-244 is chosen as a radioisotope heat source and a thermal reductive layer is also used to obtain precise thermionic emissions. The self-sufficiency principle is applied by simultaneously heating up the emitting material with the radioisotope decay heat and by powering the different valves of the plasma rocket engine with the same radioisotope decay heat using a radioisotope thermoelectric generator. This rocket engine is then benchmarked against a 1 N hydrazine thruster configuration operated on one of the Pleiades-HR-1 constellation spacecraft. A maximal specific impulse and power saving of respectively 529 s and 32% are achieved with helium as propellant. Its advantages are its power saving capability, high specific impulses and simultaneous ease of storage and restart. It can however be extremely voluminous and potentially hazardous. The Kabila rocket is found to bring great benefits to the existing spacecraft and further research should optimize its geometric characteristics and investigate the physical principals of its operation.

  12. Engineering thermal engine rocket adventurer for space nuclear application

    International Nuclear Information System (INIS)

    Nam, Seung H.; Suh, Kune Y.; Kang, Seong G.

    2008-01-01

    The conceptual design for the first-of-a-kind engineering of Thermal Engine Rocket Adventure (TERA) is described. TERA comprising the Battery Omnibus Reactor Integral System (BORIS) as the heat resource and the Space Propulsion Reactor Integral System (SPRIS) as the propulsion system, is one of the advanced Nuclear Thermal Rocket (NTR) engine utilizing hydrogen (H 2 ) propellant being developed at present time. BORIS in this application is an open cycle high temperature gas cooled reactor that has eighteen fuel elements for propulsion and one fuel element for electricity generation and propellant pumping. Each fuel element for propulsion has its own small nozzle. The nineteen fuel elements are arranged into hexagonal prism shape in the core and surrounded by outer Be reflector. The TERA maximum power is 1,000 MW th , specific impulse 1,000 s, thrust 250,000 N, and the total mass is 550 kg including the reactor, turbo pump and auxiliaries. Each fuel element comprises the fuel assembly, moderators, pressure tube and small nozzle. The TERA fuel assembly is fabricated of 93% enriched 1.5 mm (U, Zr, Nb)C wafers in 25.3% voided Square Lattice Honeycomb (SLHC). The H 2 propellant passes through these flow channels. This study is concerned with thermohydrodynamic analysis of the fuel element for propulsion with hypothetical axial power distribution because nuclear analysis of TERA has not been performed yet. As a result, when the power distribution of INSPI's M-SLHC is applied to the fuel assembly, the local heat concentration of fuel is more serious and the pressure of the initial inlet H 2 is higher than those of constant average power distribution applied. This means the fuel assembly geometry of 1.5 mm fuel wafers and 25.3% voided SLHC needs to be changed in order to reduce thermal and mechanical shocks. (author)

  13. Diesel engine exhaust particulate filter with intake throttling incineration control

    Energy Technology Data Exchange (ETDEWEB)

    Ludecke, O.; Rosebrock, T.

    1980-07-08

    A description is given of a diesel engine exhaust filter and particulate incineration system in combination with a diesel engine having a normally unthrottled air induction system for admitting combustion air to the engine and an exhaust system for carrying off spent combustion products exhausted from the engine, said filter and incineration system comprising: a combustion resistant filter disposed in the exhaust system and operative to collect and retain portions of the largely carbonaceous particulate matter contained in the engine exhaust products, said fiber being capable of withstanding without substantial damage internal temperatures sufficient to burn the collected particulate matter, a throttle in the indication system and operable to restrict air flow into the engine to reduce the admittance of excess combustion air and thereby increase engine exhaust gas temperature, and means to actuate said throttle periodically during engine operation to an air flow restricting burn mode capable of raising the particulates in said filter to their combustion temperature under certain engine operating conditions and to maintain said throttle mode for an interval adequate to burn retained particulates in the filter.

  14. Engine with pulse-suppressed dedicated exhaust gas recirculation

    Science.gov (United States)

    Keating, Edward J.; Baker, Rodney E.

    2016-06-07

    An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.

  15. Measurements of ion concentration in gasoline and diesel engine exhaust

    Science.gov (United States)

    Yu, Fangqun; Lanni, Thomas; Frank, Brian P.

    The nanoparticles formed in motor vehicle exhaust have received increasing attention due to their potential adverse health effects. It has been recently proposed that combustion-generated ions may play a critical role in the formation of these volatile nanoparticles. In this paper, we design an experiment to measure the total ion concentration in motor vehicle engine exhaust, and report some preliminary measurements in the exhaust of a gasoline engine (K-car) and a diesel engine (diesel generator). Under the experimental set-up reported in this study and for the specific engines used, the total ion concentration is ca. 3.3×10 6 cm -3 with almost all of the ions smaller than 3 nm in the gasoline engine exhaust, and is above 2.7×10 8 cm -3 with most of the ions larger than 3 nm in the diesel engine exhaust. This difference in the measured ion properties is interpreted as a result of the different residence times of exhaust inside the tailpipe/connecting pipe and the different concentrations of soot particles in the exhaust. The measured ion concentrations appear to be within the ranges predicted by a theoretical model describing the evolution of ions inside a pipe.

  16. Performance of a RBCC Engine in Rocket-Operation

    Science.gov (United States)

    Tomioka, Sadatake; Kubo, Takahiro; Noboru Sakuranaka; Tani, Koichiro

    Combination of a scramjet (supersonic combustion ramjet) flow-pass with embedded rocket engines (the combined system termed as Rocket-based Combined Cycle engine) are expected to be the most effective propulsion system for space launch vehicles. Either SSTO (Single Stage To Orbit) system or TSTO (Two Stage To Orbit) system with separation at high altitude needs final stage acceleration in space, so that the RBCC (Rocket Based Combined Cycle) engine should be operated as rocket engines. Performance of the scramjet combustor as the extension to the rocket nozzle, was experimentally evaluated by injecting inert gas at various pressure through the embedded rocket chamber while the whole sub-scaled model was placed in a low pressure chamber connected to an air-driven ejector system. The results showed that the thrust coefficient was about 1.2, the low value being found to mainly due to the friction force on the scramjet combustor wall, while blocking the scramjet flow pass’s opening to increase nozzle extension thrust surface, was found to have little effects on the thrust performance. The combustor was shortened to reduce the friction loss, however, degree of reduction was limited as friction decreased rapidly with distance from the onset of the scramjet combustor.

  17. Engineering task plan for five portable exhausters

    International Nuclear Information System (INIS)

    Rensink, G.E.

    1997-01-01

    Exhausters will be employed to ventilate certain single-shell tanks (SSTs) during salt well pumping campaigns. Active ventilation is necessary to reduce the potential flammable gas inventory (LANL 1996a) in the dome space that may accumulate during steady-state conditions or during/after postulated episodic gas release events. The tanks described in this plan support the activities required to fabricate and test three 500 cfm portable exhausters in the 200 W area shops, and to procure, design, fabricate and test two 1000 cfm units. Appropriate Notice of Construction (NOC) radiological and toxic air pollutant permits will be obtained for the portable exhausters. The portable exhauster design media to be employed to support this task was previously developed for the 241-A-101 exhauster. The same design as A101 will be fabricated with only minor improvements to the design based upon operator input/lessons learned. The safety authorization basis for this program effort will follow SAD 36 (LANL 1996b), and each tank will be reviewed against this SAD for changes or updates. The 1000 cfm units will be designed by the selected offsite contractor according to the specification requirements in KHC-S-O490. The offsite units have been specified to utilize as many of the same components as the 500 cfm units to ensure a more cost effective operation and maintenance through the reduction of spare parts and additional procedures

  18. A Historical Systems Study of Liquid Rocket Engine Throttling Capabilities

    Science.gov (United States)

    Betts, Erin M.; Frederick, Robert A., Jr.

    2010-01-01

    This is a comprehensive systems study to examine and evaluate throttling capabilities of liquid rocket engines. The focus of this study is on engine components, and how the interactions of these components are considered for throttling applications. First, an assessment of space mission requirements is performed to determine what applications require engine throttling. A background on liquid rocket engine throttling is provided, along with the basic equations that are used to predict performance. Three engines are discussed that have successfully demonstrated throttling. Next, the engine system is broken down into components to discuss special considerations that need to be made for engine throttling. This study focuses on liquid rocket engines that have demonstrated operational capability on American space launch vehicles, starting with the Apollo vehicle engines and ending with current technology demonstrations. Both deep throttling and shallow throttling engines are discussed. Boost and sustainer engines have demonstrated throttling from 17% to 100% thrust, while upper stage and lunar lander engines have demonstrated throttling in excess of 10% to 100% thrust. The key difficulty in throttling liquid rocket engines is maintaining an adequate pressure drop across the injector, which is necessary to provide propellant atomization and mixing. For the combustion chamber, cooling can be an issue at low thrust levels. For turbomachinery, the primary considerations are to avoid cavitation, stall, surge, and to consider bearing leakage flows, rotordynamics, and structural dynamics. For valves, it is necessary to design valves and actuators that can achieve accurate flow control at all thrust levels. It is also important to assess the amount of nozzle flow separation that can be tolerated at low thrust levels for ground testing.

  19. Use of Soft Computing Technologies For Rocket Engine Control

    Science.gov (United States)

    Trevino, Luis C.; Olcmen, Semih; Polites, Michael

    2003-01-01

    The problem to be addressed in this paper is to explore how the use of Soft Computing Technologies (SCT) could be employed to further improve overall engine system reliability and performance. Specifically, this will be presented by enhancing rocket engine control and engine health management (EHM) using SCT coupled with conventional control technologies, and sound software engineering practices used in Marshall s Flight Software Group. The principle goals are to improve software management, software development time and maintenance, processor execution, fault tolerance and mitigation, and nonlinear control in power level transitions. The intent is not to discuss any shortcomings of existing engine control and EHM methodologies, but to provide alternative design choices for control, EHM, implementation, performance, and sustaining engineering. The approaches outlined in this paper will require knowledge in the fields of rocket engine propulsion, software engineering for embedded systems, and soft computing technologies (i.e., neural networks, fuzzy logic, and Bayesian belief networks), much of which is presented in this paper. The first targeted demonstration rocket engine platform is the MC-1 (formerly FASTRAC Engine) which is simulated with hardware and software in the Marshall Avionics & Software Testbed laboratory that

  20. Search of archived data sources for rocket exhaust-induced modifications of the ionosphere

    International Nuclear Information System (INIS)

    Chacko, C.C.; Mendillo, M.

    1980-09-01

    The emergence of the Satellite Power System (SPS) concept as a way of augmenting the dwindling energy sources available for commercial power usage involved such a large and unprecendented technological program that detailed assessment and feasibility studies were undertaken in an attempt to specify the true impact such a program would have. As part of the issues addressed, a comprehensive environmental impact study was initiated that involved an unprecedented scope of concerns ranging from ground-level noise and weather modifications to possible planetary-scale perturbations caused by SPS activity in distant Earth orbits. This report describes results of a study of an intermediate region of the Earth's environment (the ionosphere) where large-scale perturbations are caused by routine rocket activity. The SPS program calls for vast transportation demands into and out from the ionosphere (h approx. = 200 to 1000 km), and thus the well-known effect of chemical depletions of the ionosphere (so-called ionospheric holes) caused by rocket exhaust signaled a concern over the possible large-scale and long-term consequences of the induced effects

  1. Studies of Fission Fragment Rocket Engine Propelled Spacecraft

    Science.gov (United States)

    Werka, Robert O.; Clark, Rodney; Sheldon, Rob; Percy, Thomas K.

    2014-01-01

    The NASA Office of Chief Technologist has funded from FY11 through FY14 successive studies of the physics, design, and spacecraft integration of a Fission Fragment Rocket Engine (FFRE) that directly converts the momentum of fission fragments continuously into spacecraft momentum at a theoretical specific impulse above one million seconds. While others have promised future propulsion advances if only you have the patience, the FFRE requires no waiting, no advances in physics and no advances in manufacturing processes. Such an engine unequivocally can create a new era of space exploration that can change spacecraft operation. The NIAC (NASA Institute for Advanced Concepts) Program Phase 1 study of FY11 first investigated how the revolutionary FFRE technology could be integrated into an advanced spacecraft. The FFRE combines existent technologies of low density fissioning dust trapped electrostatically and high field strength superconducting magnets for beam management. By organizing the nuclear core material to permit sufficient mean free path for escape of the fission fragments and by collimating the beam, this study showed the FFRE could convert nuclear power to thrust directly and efficiently at a delivered specific impulse of 527,000 seconds. The FY13 study showed that, without increasing the reactor power, adding a neutral gas to the fission fragment beam significantly increased the FFRE thrust through in a manner analogous to a jet engine afterburner. This frictional interaction of gas and beam resulted in an engine that continuously produced 1000 pound force of thrust at a delivered impulse of 32,000 seconds, thereby reducing the currently studied DRM 5 round trip mission to Mars from 3 years to 260 days. By decreasing the gas addition, this same engine can be tailored for much lower thrust at much higher impulse to match missions to more distant destinations. These studies created host spacecraft concepts configured for manned round trip journeys. While the

  2. Grooved Fuel Rings for Nuclear Thermal Rocket Engines

    Science.gov (United States)

    Emrich, William

    2009-01-01

    An alternative design concept for nuclear thermal rocket engines for interplanetary spacecraft calls for the use of grooved-ring fuel elements. Beyond spacecraft rocket engines, this concept also has potential for the design of terrestrial and spacecraft nuclear electric-power plants. The grooved ring fuel design attempts to retain the best features of the particle bed fuel element while eliminating most of its design deficiencies. In the grooved ring design, the hydrogen propellant enters the fuel element in a manner similar to that of the Particle Bed Reactor (PBR) fuel element.

  3. IC ENGINE SUPERCHARGING AND EXHAUST GAS RECIRCULATION USING JET COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Adhimoulame Kalaisselvane

    2010-01-01

    Full Text Available Supercharging is a process which is used to improve the performance of an engine by increasing the specific power output whereas exhaust gas recirculation reduces the NOx produced by engine because of supercharging. In a conventional engine, supercharger functions as a compressor for the forced induction of the charge taking mechanical power from the engine crankshaft. In this study, supercharging is achieved using a jet compressor. In the jet compressor, the exhaust gas is used as the motive stream and the atmospheric air as the propelled stream. When high pressure motive stream from the engine exhaust is expanded in the nozzle, a low pressure is created at the nozzle exit. Due to this low pressure, atmospheric air is sucked into the expansion chamber of the compressor, where it is mixed and pressurized with the motive stream. The pressure of the mixed stream is further increased in the diverging section of the jet compressor. A percentage volume of the pressurized air mixture is then inducted back into the engine as supercharged air and the balance is let out as exhaust. This process not only saves the mechanical power required for supercharging but also dilutes the constituents of the engine exhaust gas thereby reducing the emission and the noise level generated from the engine exhaust. The geometrical design parameters of the jet compressor were obtained by solving the governing equations using the method of constant rate of momentum change. Using the theoretical design parameters of the jet compressor, a computational fluid dinamics analysis using FLUENT software was made to evaluate the performance of the jet compressor for the application of supercharging an IC engine. This evaluation turned out to be an efficient diagnostic tool for determining performance optimization and design of the jet compressor. A jet compressor was also fabricated for the application of supercharging and its performance was studied.

  4. Capture of Heat Energy from Diesel Engine Exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  5. Review on film cooling of liquid rocket engines

    Directory of Open Access Journals (Sweden)

    S.R. Shine

    2018-03-01

    Full Text Available Film cooling in combination with regenerative cooling is presently considered as an efficient method to guarantee safe operation of liquid rocket engines having higher heat flux densities for long duration. This paper aims to bring all the research carried out in the field of liquid rocket engine film cooling since 1950. The analytical and numerical procedure followed, experimental facilities and measurements made and major inferences drawn are reviewed in detail, and compared where ever possible. Review has been made through a discussion of the analyses methodologies and the factors that influence film cooling performance. An effort has also been made to determine the status of the research, pointing out critical gaps, which are still to be explained and addressed by future generations. Keywords: Heat transfer, Liquid rocket thrust chamber, Film cooling, Cooling effectiveness

  6. Heat Pipes Reduce Engine-Exhaust Emissions

    Science.gov (United States)

    Schultz, D. F.

    1986-01-01

    Increased fuel vaporization raises engine efficiency. Heat-pipe technology increased efficiency of heat transfer beyond that obtained by metallic conduction. Resulted in both improved engine operation and reduction in fuel consumption. Raw material conservation through reduced dependence on strategic materials also benefit from this type of heat-pipe technology. Applications result in improved engine performance and cleaner environment.

  7. Multivariable optimization of liquid rocket engines using particle swarm algorithms

    Science.gov (United States)

    Jones, Daniel Ray

    Liquid rocket engines are highly reliable, controllable, and efficient compared to other conventional forms of rocket propulsion. As such, they have seen wide use in the space industry and have become the standard propulsion system for launch vehicles, orbit insertion, and orbital maneuvering. Though these systems are well understood, historical optimization techniques are often inadequate due to the highly non-linear nature of the engine performance problem. In this thesis, a Particle Swarm Optimization (PSO) variant was applied to maximize the specific impulse of a finite-area combustion chamber (FAC) equilibrium flow rocket performance model by controlling the engine's oxidizer-to-fuel ratio and de Laval nozzle expansion and contraction ratios. In addition to the PSO-controlled parameters, engine performance was calculated based on propellant chemistry, combustion chamber pressure, and ambient pressure, which are provided as inputs to the program. The performance code was validated by comparison with NASA's Chemical Equilibrium with Applications (CEA) and the commercially available Rocket Propulsion Analysis (RPA) tool. Similarly, the PSO algorithm was validated by comparison with brute-force optimization, which calculates all possible solutions and subsequently determines which is the optimum. Particle Swarm Optimization was shown to be an effective optimizer capable of quick and reliable convergence for complex functions of multiple non-linear variables.

  8. Two-step rocket engine bipropellant valve concept

    Science.gov (United States)

    Capps, J. E.; Ferguson, R. E.; Pohl, H. O.

    1969-01-01

    Initiating combustion of altitude control rocket engines in a precombustion chamber of ductile material reduces high pressure surges generated by hypergolic propellants. Two-step bipropellant valve concepts control initial propellant flow into precombustion chamber and subsequent full flow into main chamber.

  9. Analysis of supercritical methane in rocket engine cooling channels

    NARCIS (Netherlands)

    Denies, L.; Zandbergen, B.T.C.; Natale, P.; Ricci, D.; Invigorito, M.

    2016-01-01

    Methane is a promising propellant for liquid rocket engines. As a regenerative coolant, it would be close to its critical point, complicating cooling analysis. This study encompasses the development and validation of a new, open-source computational fluid dynamics (CFD) method for analysis of

  10. Diesel Engine Exhaust: Basis for Occupational Exposure Limit Value.

    Science.gov (United States)

    Taxell, Piia; Santonen, Tiina

    2017-08-01

    Diesel engines are widely used in transport and power supply, making occupational exposure to diesel exhaust common. Both human and animal studies associate exposure to diesel exhaust with inflammatory lung effects, cardiovascular effects, and an increased risk of lung cancer. The International Agency for Research on Cancer has evaluated diesel exhaust as carcinogenic to humans. Yet national or regional limit values for controlling occupational exposure to diesel exhaust are rare. In recent decades, stricter emission regulations have led to diesel technologies evolving significantly, resulting in changes in exhaust emissions and composition. These changes are also expected to influence the health effects of diesel exhaust. This review provides an overview of the current knowledge on the health effects of diesel exhaust and the influence of new diesel technologies on the health risk. It discusses the relevant exposure indicators and perspectives for setting occupational exposure limit values for diesel exhaust, and outlines directions for future research. The review is based on a collaborative evaluation report by the Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals and the Dutch Expert Committee on Occupational Safety. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Additive Manufacturing a Liquid Hydrogen Rocket Engine

    Science.gov (United States)

    Jones, Carl P.; Robertson, Elizabeth H.; Koelbl, Mary Beth; Singer, Chris

    2016-01-01

    Space Propulsion is a 5 day event being held from 2nd May to the 6th May 2016 at the Rome Marriott Park Hotel in Rome, Italy. This event showcases products like Propulsion sub-systems and components, Production and manufacturing issues, Liquid, Solid, Hybrid and Air-breathing Propulsion Systems for Launcher and Upper Stages, Overview of current programmes, AIV issues and tools, Flight testing and experience, Technology building blocks for Future Space Transportation Propulsion Systems : Launchers, Exploration platforms & Space Tourism, Green Propulsion for Space Transportation, New propellants, Rocket propulsion & global environment, Cost related aspects of Space Transportation propulsion, Modelling, Pressure-Thrust oscillations issues, Impact of new requirements and regulations on design etc. in the Automotive, Manufacturing, Fabrication, Repair & Maintenance industries.

  12. Double-reed exhaust valve engine

    Science.gov (United States)

    Bennett, Charles L.

    2015-06-30

    An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

  13. Radiation effect on rocket engine performance

    Science.gov (United States)

    Chiu, Huei-Huang; Kross, K. W.; Krebsbach, A. N.

    1990-01-01

    Critical problem areas involving the effect of radiation on the combustion of bipropellants are addressed by formulating a universal scaling law in combination with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and data pertaining to the Variable Thrust Engine (VTE) and the Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low-enthalpy engines, such as the VTE, are vulnerable to a substantial performance setback due to radiative loss, whereas the performance of high-enthalpy engines such as the SSME are hardly affected over a broad range of engine operation. Combustion enhancement by radiative heating of the propellant has a significant impact on propellants with high absorptivity.

  14. Analytical concepts for health management systems of liquid rocket engines

    Science.gov (United States)

    Williams, Richard; Tulpule, Sharayu; Hawman, Michael

    1990-01-01

    Substantial improvement in health management systems performance can be realized by implementing advanced analytical methods of processing existing liquid rocket engine sensor data. In this paper, such techniques ranging from time series analysis to multisensor pattern recognition to expert systems to fault isolation models are examined and contrasted. The performance of several of these methods is evaluated using data from test firings of the Space Shuttle main engines.

  15. Combustion response to acoustic perturbation in liquid rocket engines

    Science.gov (United States)

    Ghafourian, Akbar

    An experimental study of the effect of acoustic perturbations on combustion behavior of a model liquid propellant rocket engine has been carried out. A pair of compression drivers were used to excite transverse and longitudinal acoustic fields at strengths of up to 156.6 dB and 159.5 dB respectively in the combustion chamber of the experimental rocket engine. Propellant simulants were injected into the combustion chamber through a single element shear coaxial injector. Water and air were used in cold flow studies and ethanol and oxygen-enriched air were used as fuel and oxidizer in reacting hot flow studies. In cold flow studies an imposed transverse acoustic field had a more pronounced effect on the spray pattern than a longitudinal acoustic fields. A transverse acoustic field widened the spray by as much as 33 percent and the plane of impingement of the spray with chamber walls moved up closer to the injection plane. The behavior was strongly influenced by the gas phase velocity but was less sensitive to changes in the liquid phase velocity. In reacting hot flow studies the effects of changes in equivalence ratio, excitation amplitude, excitation frequency, liquid and gas phase velocity and chamber pressure on the response of the injector to imposed high frequency transverse acoustic excitation were measured. Reducing the equivalence ratio from 7.4 to 3.8 increased the chamber pressure response to the imposed excitation at 3000 Hz. Increasing the excitation amplitude from 147 dB to 155.6 dB at 3000 Hz increased the chamber pressure response to the excitation. In the frequency range of 1240 Hz to 3220 Hz, an excitation frequency of 3000 Hz resulted in the largest response of the chamber pressure indicating the importance of fluid dynamic coupling. Increasing the liquid phase velocity from 9.2 m/sec to 22.7 m/sec, did not change the amplitude of the chamber pressure response to excitation. This implied the importance of local equivalence ratio and not the overall

  16. Engine Cycle Analysis of Air Breathing Microwave Rocket with Reed Valves

    International Nuclear Information System (INIS)

    Fukunari, Masafumi; Komatsu, Reiji; Yamaguchi, Toshikazu; Komurasaki, Kimiya; Arakawa, Yoshihiro; Katsurayama, Hiroshi

    2011-01-01

    The Microwave Rocket is a candidate for a low cost launcher system. Pulsed plasma generated by a high power millimeter wave beam drives a blast wave, and a vehicle acquires impulsive thrust by exhausting the blast wave. The thrust generation process of the Microwave Rocket is similar to a pulse detonation engine. In order to enhance the performance of its air refreshment, the air-breathing mechanism using reed valves is under development. Ambient air is taken to the thruster through reed valves. Reed valves are closed while the inside pressure is high enough. After the time when the shock wave exhausts at the open end, an expansion wave is driven and propagates to the thrust-wall. The reed valve is opened by the negative gauge pressure induced by the expansion wave and its reflection wave. In these processes, the pressure oscillation is important parameter. In this paper, the pressure oscillation in the thruster was calculated by CFD combined with the flux through from reed valves, which is estimated analytically. As a result, the air-breathing performance is evaluated using Partial Filling Rate (PFR), the ratio of thruster length to diameter L/D, and ratio of opening area of reed valves to superficial area α. An engine cycle and predicted thrust was explained.

  17. REVIEW ARTICLE: MODELLING AND ANALYSIS OF A GASOLINE ENGINE EXHAUST GAS SYSTEMS

    OpenAIRE

    Barhm Mohamad

    2018-01-01

    The engine exhaust gas behaviour is strongly influencing the engine performance. This paper presents the modelling and analysis of four stroke - gasoline engine exhaust gas systems. An automotive example is considered whereby the pulsating exhausts gas flow through an exhaust pipe and silencer are considered over a wide range of speeds. Analytical procedures are outlined enabling the general analysis and modelling of vehicle engine exhaust gas systems also in this paper present...

  18. Ionospheric effects of rocket exhaust products: Skylab and HEAO-C

    International Nuclear Information System (INIS)

    Zinn, J.; Sutherland, C.D.; Duncan, L.M.; Stone, S.N.

    1981-01-01

    This paper is about ionospheric F-layer depletions produced by chemical reactions with exhaust gases from large rockets. It describes a 2-dimensional computer model of the ionosphere, and it compares model results with experimental data on the structure and variability of the natural ionosphere, as well as data on ionospheric holes produced by the launches of Skylab (May, 1973) and HEAO-C (September, 1979). It also describes measurements made in conjunction with the HEAO-C launch. The computer model includes an approximate representation of thermospheric tidal winds and E fields in addition to vertical motions associated with diurnal changes in temperature. The computed ionospheric structure is sensitive to all the above. For a small number of cases, results are compared of computations of the normal diurnal variations of ionospheric structure with incoherent scatter and total electron content data. Computations of ionospheric depletions from the Skylab and HEAO-C launches are in satisfactory agreement with the observations. The winds appear to be essential for interpretation of the Skylab results

  19. Improving of Hybrid Rocket Engine on the Basis of Optimizing Design Fuel Grain

    Science.gov (United States)

    Oriekov, K. M.; Ushkin, M. P.

    2015-09-01

    This article examines the processes intrachamber in hybrid rocket engine (HRE) and the comparative assessment of the use of solid rocket motors (SRM) and HRE for meteorological rockets with a mass of payload of the 364 kg. Results of the research showed the possibility of a significant increase in the ballistic effectiveness of meteorological rocket.

  20. Opportunity to reduce the exhaust gases with engine adjust

    International Nuclear Information System (INIS)

    Dimitrovski, Mile; Mucevski, Kiril

    2002-01-01

    According to statistics in the Republic of Macedonia, the number of old vehicles is about 90%. These are vehicles produced between 1975 and 1990 with classical systems for forming and burning the fuel mixture. The most of them do not have system for processing exhaust gases (catalytic converter) and are serious air pollutants of carbon monoxide (CO). In this article we try to make an attempt to reduce exhaust gases in some kinds of these vehicles with adjusting to the system for burning fuel mixture and with adjusting to the system for forming fuel mixture (carburetor). At the same time the changes on the rotate bending moment and engine power are followed. It is noticed that with a proper adjustment the emission of exhaust gases can be reduced without a serious depreciation of the rotate bending moment and the engine power. (Author)

  1. Expert System Architecture for Rocket Engine Numerical Simulators: A Vision

    Science.gov (United States)

    Mitra, D.; Babu, U.; Earla, A. K.; Hemminger, Joseph A.

    1998-01-01

    Simulation of any complex physical system like rocket engines involves modeling the behavior of their different components using mostly numerical equations. Typically a simulation package would contain a set of subroutines for these modeling purposes and some other ones for supporting jobs. A user would create an input file configuring a system (part or whole of a rocket engine to be simulated) in appropriate format understandable by the package and run it to create an executable module corresponding to the simulated system. This module would then be run on a given set of input parameters in another file. Simulation jobs are mostly done for performance measurements of a designed system, but could be utilized for failure analysis or a design job such as inverse problems. In order to use any such package the user needs to understand and learn a lot about the software architecture of the package, apart from being knowledgeable in the target domain. We are currently involved in a project in designing an intelligent executive module for the rocket engine simulation packages, which would free any user from this burden of acquiring knowledge on a particular software system. The extended abstract presented here will describe the vision, methodology and the problems encountered in the project. We are employing object-oriented technology in designing the executive module. The problem is connected to the areas like the reverse engineering of any simulation software, and the intelligent systems for simulation.

  2. Active compressor engine silencer reduces exhaust noise

    International Nuclear Information System (INIS)

    Denenberg, J.N.; Miller, S.K.; Jay, M.A.

    1994-01-01

    An active industrial silencer on a compressor engine at a Tenneco Gas station has reduced low-frequency 'rumbling' noise by 8 dB during trials while lowering backpressure about 90$. This 8 dB reduction of the piston firing frequency corresponds to a more than 80% decrease in emitted acoustic power. The silencing unit, installed on one of six engines at the station near Eden, N.Y., continues in operation. Based on the results, the manufacturer is identifying additional compressor sites for further tests. This paper reviews this project

  3. Occupational exposure to diesel engine exhaust and serum cytokine levels

    NARCIS (Netherlands)

    Dai, Yufei; Ren, Dianzhi; Bassig, Bryan A.; Vermeulen, Roel; Hu, Wei; Niu, Yong; Duan, Huawei; Ye, Meng; Meng, Tao; Xu, Jun; Li, Ping; Shen, Meili; Yang, Jufang; Fu, Wei; Meliefste, Kees; Silverman, Debra T.; Rothman, Nathaniel; Lan, Qing; Zheng, Yuxin

    The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response

  4. Parallelization of Rocket Engine Simulator Software (PRESS)

    Science.gov (United States)

    Cezzar, Ruknet

    1998-01-01

    /18/99). At the least, the research would need to be done on Windows 95/Windows NT based platforms. Moreover, with the acquisition of Lahey Fortran package for PC platform, and the existing Borland C + + 5. 0, we can do work on C + + wrapper issues. We have carefully studied the blueprint for Space Transportation Propulsion Integrated Design Environment for the next 25 years [13] and found the inclusion of HBCUs in that effort encouraging. Especially in the long period for which a map is provided, there is no doubt that HBCUs will grow and become better equipped to do meaningful research. In the shorter period, as was suggested in our presentation at the HBCU conference, some key decisions regarding the aging Fortran based software for rocket propellants will need to be made. One important issue is whether or not object oriented languages such as C + + or Java should be used for distributed computing. Whether or not "distributed computing" is necessary for the existing software is yet another, larger, question to be tackled with.

  5. Review on pressure swirl injector in liquid rocket engine

    Science.gov (United States)

    Kang, Zhongtao; Wang, Zhen-guo; Li, Qinglian; Cheng, Peng

    2018-04-01

    The pressure swirl injector with tangential inlet ports is widely used in liquid rocket engine. Commonly, this type of pressure swirl injector consists of tangential inlet ports, a swirl chamber, a converging spin chamber, and a discharge orifice. The atomization of the liquid propellants includes the formation of liquid film, primary breakup and secondary atomization. And the back pressure and temperature in the combustion chamber could have great influence on the atomization of the injector. What's more, when the combustion instability occurs, the pressure oscillation could further affects the atomization process. This paper reviewed the primary atomization and the performance of the pressure swirl injector, which include the formation of the conical liquid film, the breakup and atomization characteristics of the conical liquid film, the effects of the rocket engine environment, and the response of the injector and atomization on the pressure oscillation.

  6. Numerically Modeling the Erosion of Lunar Soil by Rocket Exhaust Plumes

    Science.gov (United States)

    2008-01-01

    In preparation for the Apollo program, Leonard Roberts of the NASA Langley Research Center developed a remarkable analytical theory that predicts the blowing of lunar soil and dust beneath a rocket exhaust plume. Roberts assumed that the erosion rate was determined by the excess shear stress in the gas (the amount of shear stress greater than what causes grains to roll). The acceleration of particles to their final velocity in the gas consumes a portion of the shear stress. The erosion rate continues to increase until the excess shear stress is exactly consumed, thus determining the erosion rate. Roberts calculated the largest and smallest particles that could be eroded based on forces at the particle scale, but the erosion rate equation assumed that only one particle size existed in the soil. He assumed that particle ejection angles were determined entirely by the shape of the terrain, which acts like a ballistic ramp, with the particle aerodynamics being negligible. The predicted erosion rate and the upper limit of particle size appeared to be within an order of magnitude of small-scale terrestrial experiments but could not be tested more quantitatively at the time. The lower limit of particle size and the predictions of ejection angle were not tested. We observed in the Apollo landing videos that the ejection angles of particles streaming out from individual craters were time-varying and correlated to the Lunar Module thrust, thus implying that particle aerodynamics dominate. We modified Roberts theory in two ways. First, we used ad hoc the ejection angles measured in the Apollo landing videos, in lieu of developing a more sophisticated method. Second, we integrated Roberts equations over the lunar-particle size distribution and obtained a compact expression that could be implemented in a numerical code. We also added a material damage model that predicts the number and size of divots which the impinging particles will cause in hardware surrounding the landing

  7. Research Technology (ASTP) Rocket Based Combined Cycle (RBCC) Engine

    Science.gov (United States)

    2004-01-01

    Pictured is an artist's concept of the Rocket Based Combined Cycle (RBCC) launch. The RBCC's overall objective is to provide a technology test bed to investigate critical technologies associated with opperational usage of these engines. The program will focus on near term technologies that can be leveraged to ultimately serve as the near term basis for Two Stage to Orbit (TSTO) air breathing propulsions systems and ultimately a Single Stage To Orbit (SSTO) air breathing propulsion system.

  8. Health management system for rocket engines

    Science.gov (United States)

    Nemeth, Edward

    1990-01-01

    The functional framework of a failure detection algorithm for the Space Shuttle Main Engine (SSME) is developed. The basic algorithm is based only on existing SSME measurements. Supplemental measurements, expected to enhance failure detection effectiveness, are identified. To support the algorithm development, a figure of merit is defined to estimate the likelihood of SSME criticality 1 failure modes and the failure modes are ranked in order of likelihood of occurrence. Nine classes of failure detection strategies are evaluated and promising features are extracted as the basis for the failure detection algorithm. The failure detection algorithm provides early warning capabilities for a wide variety of SSME failure modes. Preliminary algorithm evaluation, using data from three SSME failures representing three different failure types, demonstrated indications of imminent catastrophic failure well in advance of redline cutoff in all three cases.

  9. History of the Development of NERVA Nuclear Rocket Engine Technology

    International Nuclear Information System (INIS)

    David L., Black

    2000-01-01

    During the 17 yr between 1955 and 1972, the Atomic Energy Commission (AEC), the U.S. Air Force (USAF), and the National Aeronautics and Space Administration (NASA) collaborated on an effort to develop a nuclear rocket engine. Based on studies conducted in 1946, the concept selected was a fully enriched uranium-filled, graphite-moderated, beryllium-reflected reactor, cooled by a monopropellant, hydrogen. The program, known as Rover, was centered at Los Alamos Scientific Laboratory (LASL), funded jointly by the AEC and the USAF, with the intent of designing a rocket engine for long-range ballistic missiles. Other nuclear rocket concepts were studied during these years, such as cermet and gas cores, but are not reviewed herein. Even thought the program went through the termination phase in a very short time, the technology may still be fully recoverable/retrievable to the state of its prior technological readiness in a reasonably short time. Documents; drawings; and technical, purchasing, manufacturing, and materials specifications were all stored for ease of retrieval. If the U.S. space program were to discover a need/mission for this engine, its 1972 'pencils down' status could be updated for the technology developments of the past 28 yr for flight demonstration in 8 or fewer years. Depending on today's performance requirements, temperatures and pressures could be increased and weight decreased considerably

  10. Designing Liquid Rocket Engine Injectors for Performance, Stability, and Cost

    Science.gov (United States)

    Westra, Douglas G.; West, Jeffrey S.

    2014-01-01

    NASA is developing the Space Launch System (SLS) for crewed exploration missions beyond low Earth orbit. Marshall Space Flight Center (MSFC) is designing rocket engines for the SLS Advanced Booster (AB) concepts being developed to replace the Shuttle-derived solid rocket boosters. One AB concept uses large, Rocket-Propellant (RP)-fueled engines that pose significant design challenges. The injectors for these engines require high performance and stable operation while still meeting aggressive cost reduction goals for access to space. Historically, combustion stability problems have been a critical issue for such injector designs. Traditional, empirical injector design tools and methodologies, however, lack the ability to reliably predict complex injector dynamics that often lead to combustion stability. Reliance on these tools alone would likely result in an unaffordable test-fail-fix cycle for injector development. Recently at MSFC, a massively parallel computational fluid dynamics (CFD) program was successfully applied in the SLS AB injector design process. High-fidelity reacting flow simulations were conducted for both single-element and seven-element representations of the full-scale injector. Data from the CFD simulations was then used to significantly augment and improve the empirical design tools, resulting in a high-performance, stable injector design.

  11. Organic positive ions in aircraft gas-turbine engine exhaust

    Science.gov (United States)

    Sorokin, Andrey; Arnold, Frank

    Volatile organic compounds (VOCs) represent a significant fraction of atmospheric aerosol. However the role of organic species emitted by aircraft (as a consequence of the incomplete combustion of fuel in the engine) in nucleation of new volatile particles still remains rather speculative and requires a much more detailed analysis of the underlying mechanisms. Measurements in aircraft exhaust plumes have shown the presence of both different non-methane VOCs (e.g. PartEmis project) and numerous organic cluster ions (MPIK-Heidelberg). However the link between detected organic gas-phase species and measured mass spectrum of cluster ions is uncertain. Unfortunately, up to now there are no models describing the thermodynamics of the formation of primary organic cluster ions in the exhaust of aircraft engines. The aim of this work is to present first results of such a model development. The model includes the block of thermodynamic data based on proton affinities and gas basicities of organic molecules and the block of non-equilibrium kinetics of the cluster ions evolution in the exhaust. The model predicts important features of the measured spectrum of positive ions in the exhaust behind aircraft. It is shown that positive ions emitted by aircraft engines into the atmosphere mostly consist of protonated and hydrated organic cluster ions. The developed model may be explored also in aerosol investigations of the background atmosphere as well as in the analysis of the emission of fine aerosol particles by automobiles.

  12. PIXE analysis of exhaust gas from diesel engine

    International Nuclear Information System (INIS)

    Miyake, Hirosi; Michijima, Masami; Onishi, Masayuki; Fujitani, Tatsuya.

    1986-01-01

    The variation of elemental concentrations in exhaust gas of a Diesel engine with the outputs was studied. Particulates in high temperature gas were collected on silica fiber filters and analyzed by PIXE method. Concentrations of S and V were nearly proportional to particulate masses and fuel consumption rates per discharging rates of exhaust gas respectively. While, concentrations of Fe and Mn were markedly increased together with engine outputs, and Mn/Fe ratios were nearly equal to those of the material of piston rings and the cylinder liner. Concentrations of the elements contained in lubricant, such as Ca and Mo, were also conspicuously increased with the outputs. It was shown that PIXE analysis is a useful tool for engine diagonostics owing to its high sensitive multi-elemental availability without chemical treatments. (author)

  13. Exhaust emissions from an indirect injection dual-fuel engine

    International Nuclear Information System (INIS)

    Abd Alla, G.H.; Badr, O.A.; Soliman, H.A.; Abd Rabbo, M.F.

    2000-01-01

    Diesel engines operating on gaseous fuels are commonly known as dual-fuel engines. In the present work, a single-cylinder, compression ignition, indirect injection research (Ricardo E6) engine has been installed at United Arab Emirates University for investigation of the exhaust emissions when the engine is operating as a dual-fuel engine. The influence of changes in major operating and design parameters, such as the concentration of gaseous fuel in the cylinder charge, pilot fuel quantity, injection timing and intake temperature, on the production of exhaust emissions was investigated. Diesel fuel was used as the pilot fuel, while methane or propane was used as the main fuel which was inducted in the intake manifold and mixed with the intake air. The experimental investigations showed that the poor emissions at light loads can be improved significantly by increasing the concentration of gaseous fuel (total equivalence ratio), employing a large pilot fuel quantity, advancing the injection timing of the pilot fuel and increasing the intake temperature. It is demonstrated that, in general, any measure that tends to increase the size of the combustion regions within the overly lean cylinder charge will reduce markedly the concentrations of unburned hydrocarbons and carbon monoxide in the exhaust gases. (Author)

  14. Exhaust emissions from an indirect injection dual-fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Abd Alla, G.H.; Badr, O.A.; Soliman, H.A.; Abd Rabbo, M.F. [Zagazig Univ., Dept. of Mechanical Engineering, Cairo (Egypt)

    2000-04-01

    Diesel engines operating on gaseous fuels are commonly known as dual-fuel engines. In the present work, a single-cylinder, compression ignition, indirect injection research (Ricardo E6) engine has been installed at United Arab Emirates University for investigation of the exhaust emissions when the engine is operating as a dual-fuel engine. The influence of changes in major operating and design parameters, such as the concentration of gaseous fuel in the cylinder charge, pilot fuel quantity, injection timing and intake temperature, on the production of exhaust emissions was investigated. Diesel fuel was used as the pilot fuel, while methane or propane was used as the main fuel which was inducted in the intake manifold and mixed with the intake air. The experimental investigations showed that the poor emissions at light loads can be improved significantly by increasing the concentration of gaseous fuel (total equivalence ratio), employing a large pilot fuel quantity, advancing the injection timing of the pilot fuel and increasing the intake temperature. It is demonstrated that, in general, any measure that tends to increase the size of the combustion regions within the overly lean cylinder charge will reduce markedly the concentrations of unburned hydrocarbons and carbon monoxide in the exhaust gases. (Author)

  15. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H{sub 2}) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H{sub 2} propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub s}p) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H{sub 2} temperature of a NTR is around 3,000 K, the I{sub s}p can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived

  16. Development of CFD model for augmented core tripropellant rocket engine

    Science.gov (United States)

    Jones, Kenneth M.

    1994-10-01

    The Space Shuttle era has made major advances in technology and vehicle design to the point that the concept of a single-stage-to-orbit (SSTO) vehicle appears more feasible. NASA presently is conducting studies into the feasibility of certain advanced concept rocket engines that could be utilized in a SSTO vehicle. One such concept is a tripropellant system which burns kerosene and hydrogen initially and at altitude switches to hydrogen. This system will attain a larger mass fraction because LOX-kerosene engines have a greater average propellant density and greater thrust-to-weight ratio. This report describes the investigation to model the tripropellant augmented core engine. The physical aspects of the engine, the CFD code employed, and results of the numerical model for a single modular thruster are discussed.

  17. Evaluation of undeveloped rocket engine cycle applications to advanced transportation

    Science.gov (United States)

    1990-01-01

    Undeveloped pump-fed, liquid propellant rocket engine cycles were assessed and evaluated for application to Next Manned Transportation System (NMTS) vehicles, which would include the evolving Space Transportation System (STS Evolution), the Personnel Launch System (PLS), and the Advanced Manned Launch System (AMLS). Undeveloped engine cycles selected for further analysis had potential for increased reliability, more maintainability, reduced cost, and improved (or possibly level) performance when compared to the existing SSME and proposed STME engines. The split expander (SX) cycle, the full flow staged combustion (FFSC) cycle, and a hybrid version of the FFSC, which has a LOX expander drive for the LOX pump, were selected for definition and analysis. Technology requirements and issues were identified and analyses of vehicle systems weight deltas using the SX and FFSC cycles in AMLS vehicles were performed. A strawman schedule and cost estimate for FFSC subsystem technology developments and integrated engine system demonstration was also provided.

  18. Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

    Science.gov (United States)

    Greene, William D. (Inventor)

    2008-01-01

    A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

  19. Performance and exhaust emissions of a biodiesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Canakci, Mustafa [Kocaeli University, Technical Education Faculty, 41380 Kocaeli (Turkey); Erdil, Ahmet [Kocaeli University, Engineering Faculty, 41040 Kocaeli (Turkey); Arcaklioglu, Erol [Kirikkale University, Engineering Faculty, 71450 Kirikkale (Turkey)

    2006-06-15

    In this study, the applicabilities of Artificial Neural Networks (ANNs) have been investigated for the performance and exhaust-emission values of a diesel engine fueled with biodiesels from different feedstocks and petroleum diesel fuels. The engine performance and emissions characteristics of two different petroleum diesel-fuels (No. 1 and No. 2), biodiesels (from soybean oil and yellow grease), and their 20% blends with No. 2 diesel fuel were used as experimental results. The fuels were tested at full load (100%) at 1400-rpm engine speed, where the engine torque was 257.6Nm. To train the network, the average molecular weight, net heat of combustion, specific gravity, kinematic viscosity, C/H ratio and cetane number of each fuel are used as the input layer, while outputs are the brake specific fuel-consumption, exhaust temperature, and exhaust emissions. The back-propagation learning algorithm with three different variants, single layer, and logistic sigmoid transfer function were used in the network. By using weights in the network, formulations have been given for each output. The network has yielded R{sup 2} values of 0.99 and the mean % errors are smaller than 4.2 for the training data, while the R{sup 2} values are about 0.99 and the mean % errors are smaller than 5.5 for the test data. The performance and exhaust emissions from a diesel engine, using biodiesel blends with No. 2 diesel fuel up to 20%, have been predicted using the ANN model. sing the ANN model. (author)

  20. Numerical Simulation of Rocket Exhaust Interaction with Lunar Soil, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Rocket plume impingement may cause significant damage and contaminate co-landed spacecraft and surrounding habitat structures during Lunar landing operations. Under...

  1. Investigation of the cooling film distribution in liquid rocket engine

    Directory of Open Access Journals (Sweden)

    Luís Antonio Silva

    2011-05-01

    Full Text Available This study presents the results of the investigation of a cooling method widely used in the combustion chambers, which is called cooling film, and it is applied to a liquid rocket engine that uses as propellants liquid oxygen and kerosene. Starting from an engine cooling, whose film is formed through the fuel spray guns positioned on the periphery of the injection system, the film was experimentally examined, it is formed by liquid that seeped through the inner wall of the combustion chamber. The parameter used for validation and refinement of the theoretical penetration of the film was cooling, as this parameter is of paramount importance to obtain an efficient thermal protection inside the combustion chamber. Cold tests confirmed a penetrating cold enough cooling of the film for the length of the combustion chamber of the studied engine.

  2. Reusable rocket engine preventive maintenance scheduling using genetic algorithm

    International Nuclear Information System (INIS)

    Chen, Tao; Li, Jiawen; Jin, Ping; Cai, Guobiao

    2013-01-01

    This paper deals with the preventive maintenance (PM) scheduling problem of reusable rocket engine (RRE), which is different from the ordinary repairable systems, by genetic algorithm. Three types of PM activities for RRE are considered and modeled by introducing the concept of effective age. The impacts of PM on all subsystems' aging processes are evaluated based on improvement factor model. Then the reliability of engine is formulated by considering the accumulated time effect. After that, optimization model subjected to reliability constraint is developed for RRE PM scheduling at fixed interval. The optimal PM combination is obtained by minimizing the total cost in the whole life cycle for a supposed engine. Numerical investigations indicate that the subsystem's intrinsic reliability characteristic and the improvement factor of maintain operations are the most important parameters in RRE's PM scheduling management

  3. Hybrid rocket engine research program at Ryerson University

    Energy Technology Data Exchange (ETDEWEB)

    Karpynczyk, J.; Greatrix, D.R. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Aerospace Engineering

    2007-07-01

    Hybrid rocket engines (HREs) are a combination of solid and liquid propellant rocket engine designs. A solid fuel grain is located in the main combustion chamber and nozzle aft, while a stored liquid or gaseous oxidizer source supplies the required oxygen content through a throttle valve, for combustion downstream in the main chamber. HREs have drawn significant interest in certain flight applications, as they can be advantageous in terms of cost, ease and safety in storage, controllability in flight, and availability of propellant constituents. Key factors that will lead to further practical usage of HREs for flight applications are their predictability and reproducibility of operational performance. This paper presented information on studies being conducted at Ryerson University aimed at analyzing and testing the performance of HREs. It discussed and illustrated the conventional HRE and analyzed engine performance considerations such as the fuel regression rate, mass flux about the fuel surface, burning rate, and zero transformation parameter. Other factors relating to HRE performance that were presented included induced forward and aft oxidizer flow swirl effects as a means for augmenting the fuel regression rate, stoichiometric grain length issues, and feed system stability. Last, the paper presented a simplified schematic diagram of a proposed thrust/test stand for HRE test firings. 2 refs., 3 figs.

  4. Using Innovative Technologies for Manufacturing and Evaluating Rocket Engine Hardware

    Science.gov (United States)

    Betts, Erin M.; Hardin, Andy

    2011-01-01

    Many of the manufacturing and evaluation techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing and evaluating hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) and white light scanning are being adopted and evaluated for their use on J-2X, with hopes of employing both technologies on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powdered metal manufacturing process in order to produce complex part geometries. The white light technique is a non-invasive method that can be used to inspect for geometric feature alignment. Both the DMLS manufacturing method and the white light scanning technique have proven to be viable options for manufacturing and evaluating rocket engine hardware, and further development and use of these techniques is recommended.

  5. Net-Shape HIP Powder Metallurgy Components for Rocket Engines

    Science.gov (United States)

    Bampton, Cliff; Goodin, Wes; VanDaam, Tom; Creeger, Gordon; James, Steve

    2005-01-01

    True net shape consolidation of powder metal (PM) by hot isostatic pressing (HIP) provides opportunities for many cost, performance and life benefits over conventional fabrication processes for large rocket engine structures. Various forms of selectively net-shape PM have been around for thirty years or so. However, it is only recently that major applications have been pursued for rocket engine hardware fabricated in the United States. The method employs sacrificial metallic tooling (HIP capsule and shaped inserts), which is removed from the part after HIP consolidation of the powder, by selective acid dissolution. Full exploitation of net-shape PM requires innovative approaches in both component design and materials and processing details. The benefits include: uniform and homogeneous microstructure with no porosity, irrespective of component shape and size; elimination of welds and the associated quality and life limitations; removal of traditional producibility constraints on design freedom, such as forgeability and machinability, and scale-up to very large, monolithic parts, limited only by the size of existing HIP furnaces. Net-shape PM HIP also enables fabrication of complex configurations providing additional, unique functionalities. The progress made in these areas will be described. Then critical aspects of the technology that still require significant further development and maturation will be discussed from the perspective of an engine systems builder and end-user of the technology.

  6. An intelligent instrument for measuring exhaust temperature of marine engine

    Science.gov (United States)

    Ma, Nan-Qi; Su, Hua; Liu, Jun

    2006-12-01

    Exhaust temperature of the marine engine is commonly measured through thermocouple. Measure deviation will occur after using the thermocouple for some time due to nonlinearity of thermocouple itself, high temperature and chemical corrosion of measure point. Frequent replacement of thermocouple will increase the operating cost. This paper designs a new intelligent instrument for solving the above-mentioned problems of the marine engine temperature measurement, which combines the conventional thermocouple temperature measurement technology and SCM(single chip microcomputer). The reading of the thermocouple is simple and precise and the calibration can be made automatically and manually.

  7. Adaptive feedforward control of exhaust recirculation in large diesel engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars

    2017-01-01

    is generalized to a class of first order Hammerstein systems with sensor delay and exponentially converging bounds of the control error are proven analytically. It is then shown how to apply the method to the EGR system of a two-stroke crosshead diesel engine. The controller is validated by closed loop......Environmental concern has led the International Maritime Organization to restrict NO푥 emissions from marine diesel engines. Exhaust gas recirculation (EGR) systems have been introduced in order to comply to the new standards. Traditional fixed-gain feedback methods are not able to control the EGR...

  8. Effects of rocket engines on laser during lunar landing

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Xiong, E-mail: wanxiong1@126.com [Key Laboratory of Space Active Opto-Electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083 (China); Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang 330063 (China); Shu, Rong; Huang, Genghua [Key Laboratory of Space Active Opto-Electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083 (China)

    2013-11-15

    In the Chinese moon exploration project “ChangE-3”, the laser telemeter and lidar are important equipments on the lunar landing vehicle. A low-thrust vernier rocket engine works during the soft landing, whose plume may influence on the laser equipments. An experiment has first been accomplished to evaluate the influence of the plume on the propagation characteristics of infrared laser under the vacuum condition. Combination with our theoretical analysis has given an appropriate assessment of the plume's effects on the infrared laser hence providing a valuable basis for the design of lunar landing systems.

  9. Effects of rocket engines on laser during lunar landing

    International Nuclear Information System (INIS)

    Wan, Xiong; Shu, Rong; Huang, Genghua

    2013-01-01

    In the Chinese moon exploration project “ChangE-3”, the laser telemeter and lidar are important equipments on the lunar landing vehicle. A low-thrust vernier rocket engine works during the soft landing, whose plume may influence on the laser equipments. An experiment has first been accomplished to evaluate the influence of the plume on the propagation characteristics of infrared laser under the vacuum condition. Combination with our theoretical analysis has given an appropriate assessment of the plume's effects on the infrared laser hence providing a valuable basis for the design of lunar landing systems

  10. On the hydrodynamics of rocket propellant engine inducers and turbopumps

    International Nuclear Information System (INIS)

    D'Agostino, L

    2013-01-01

    The lecture presents an overview of some recent results of the work carried out at Alta on the hydrodynamic design and rotordynamic fluid forces of cavitating turbopumps for liquid propellant feed systems of modern rocket engines. The reduced order models recently developed for preliminary geometric definition and noncavitating performance prediction of tapered-hub axial inducers and centrifugal turbopumps are illustrated. The experimental characterization of the rotordynamic forces acting on a whirling four-bladed, tapered-hub, variable-pitch high-head inducer, under different load and cavitation conditions is presented. Future perspectives of the work to be carried out at Alta in this area of research are briefly illustrated

  11. Generation and characterization of gasoline engine exhaust inhalation exposure atmospheres.

    Science.gov (United States)

    McDonald, Jacob D; Barr, Edward B; White, Richard K; Kracko, Dean; Chow, Judith C; Zielinska, Barbara; Grosjean, Eric

    2008-10-01

    Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 4.3-L gasoline engine coupled to a dynamometer and operated on an adapted California Unified Driving Cycle. Exposure levels were maintained at three different dilution rates. One chamber at the lowest dilution had particles removed by filtration. Each exposure atmosphere was characterized for particle mass, particle number, particle size distribution, and detailed chemical speciation. The majority of the mass in the exposure atmospheres was gaseous carbon monoxide, nitrogen oxides, and volatile organics, with small amounts of particle-bound carbon/ions and metals. The atmospheres varied according to the cycle, with the largest spikes in volatile organic and inorganic species shown during the "cold start" portion of the cycle. Ammonia present from the exhaust and rodents interacted with the gasoline exhaust to form secondary inorganic particles, and an increase in exhaust resulted in higher proportions of secondary inorganics as a portion of the total particle mass. Particle size had a median of 10-20 nm by number and approximately 150 nm by mass. Volatile organics matched the composition of the fuel, with large proportions of aliphatic and aromatic hydrocarbons coupled to low amounts of oxygenated organics. A new measurement technique revealed organics reacting with nitrogen oxides have likely resulted in measurement bias in previous studies of combustion emissions. Identified and measured particle organic species accounted for about 10% of total organic particle mass and were mostly aliphatic acids and polycyclic aromatic hydrocarbons.

  12. Advances for laser ignition of internal combustion and rocket engines

    International Nuclear Information System (INIS)

    Schwarz, E.

    2011-01-01

    The scope of the PhD thesis presented here is the investigation of theoretical and practical aspects of laser-induced spark ignition and laser thermal ignition. Laser ignition systems are currently undergoing a rapidly development with growing intensity involving more and more research groups who mainly concentrate on the field of car and large combustion engines. This research is primarily driven by the engagement to meet the increasingly strict emission limits and by the intention to use the limited energy reserves more efficiently. For internal combustion engines, laser plasma-induced ignition will allow to combine the goals for legally required reductions of pollutant emissions and higher engine efficiencies. Also for rocket engines laser ignition turns out to be very attractive. A highly reliable ignition system like laser ignition would represent an option for introducing non-toxic propellants in order to replace highly toxic and carcinogenic hydrazine-based propellants commonly used in launch vehicle upper stages and satellites. The most important results on laser ignition and laser plasma generation, accomplished by the author and, in some respects, enriched by cooperation with colleagues are presented in the following. The emphasis of this thesis is placed on the following issues: - Two-color effects on laser plasma generation - Theoretical considerations about the focal volume concerning plasma generation - Plasma transmission experiments - Ignition experiments on laser-induced ignition - Ignition experiments on thermally-induced ignition - Feasibility study on laser ignition of rocket engines The purpose of the two-color laser plasma experiments is to investigate possible constructive interference effects of driving fields that are not monochromatic, but contain (second) harmonic radiation with respect to the goal of lowering the plasma generation threshold. Such effects have been found in a number of related processes, such as laser ablation or high

  13. Distributed Health Monitoring System for Reusable Liquid Rocket Engines

    Science.gov (United States)

    Lin, C. F.; Figueroa, F.; Politopoulos, T.; Oonk, S.

    2009-01-01

    The ability to correctly detect and identify any possible failure in the systems, subsystems, or sensors within a reusable liquid rocket engine is a major goal at NASA John C. Stennis Space Center (SSC). A health management (HM) system is required to provide an on-ground operation crew with an integrated awareness of the condition of every element of interest by determining anomalies, examining their causes, and making predictive statements. However, the complexity associated with relevant systems, and the large amount of data typically necessary for proper interpretation and analysis, presents difficulties in implementing complete failure detection, identification, and prognostics (FDI&P). As such, this paper presents a Distributed Health Monitoring System for Reusable Liquid Rocket Engines as a solution to these problems through the use of highly intelligent algorithms for real-time FDI&P, and efficient and embedded processing at multiple levels. The end result is the ability to successfully incorporate a comprehensive HM platform despite the complexity of the systems under consideration.

  14. Boiler and Pressure Balls Monopropellant Thermal Rocket Engine

    Science.gov (United States)

    Greene, William D. (Inventor)

    2009-01-01

    The proposed technology is a rocket engine cycle utilizing as the propulsive fluid a low molecular weight, cryogenic fluid, typically liquid hydrogen, pressure driven, heated, and expelled through a nozzle to generate high velocity and high specific impulse discharge gas. The proposed technology feeds the propellant through the engine cycle without the use of a separate pressurization fluid and without the use of turbomachinery. Advantages of the proposed technology are found in those elements of state-of-the-art systems that it avoids. It does not require a separate pressurization fluid or a thick-walled primary propellant tank as is typically required for a classical pressure-fed system. Further, it does not require the acceptance of intrinsic reliability risks associated with the use of turbomachinery

  15. Gas-Generator Augmented Expander Cycle Rocket Engine

    Science.gov (United States)

    Greene, William D. (Inventor)

    2011-01-01

    An augmented expander cycle rocket engine includes first and second turbopumps for respectively pumping fuel and oxidizer. A gas-generator receives a first portion of fuel output from the first turbopump and a first portion of oxidizer output from the second turbopump to ignite and discharge heated gas. A heat exchanger close-coupled to the gas-generator receives in a first conduit the discharged heated gas, and transfers heat to an adjacent second conduit carrying fuel exiting the cooling passages of a primary combustion chamber. Heat is transferred to the fuel passing through the cooling passages. The heated fuel enters the second conduit of the heat exchanger to absorb more heat from the first conduit, and then flows to drive a turbine of one or both of the turbopumps. The arrangement prevents the turbopumps exposure to combusted gas that could freeze in the turbomachinery and cause catastrophic failure upon attempted engine restart.

  16. Comparison of Engine Cycle Codes for Rocket-Based Combined Cycle Engines

    Science.gov (United States)

    Waltrup, Paul J.; Auslender, Aaron H.; Bradford, John E.; Carreiro, Louis R.; Gettinger, Christopher; Komar, D. R.; McDonald, J.; Snyder, Christopher A.

    2002-01-01

    This paper summarizes the results from a one day workshop on Rocket-Based Combined Cycle (RBCC) Engine Cycle Codes held in Monterey CA in November of 2000 at the 2000 JANNAF JPM with the authors as primary participants. The objectives of the workshop were to discuss and compare the merits of existing Rocket-Based Combined Cycle (RBCC) engine cycle codes being used by government and industry to predict RBCC engine performance and interpret experimental results. These merits included physical and chemical modeling, accuracy and user friendliness. The ultimate purpose of the workshop was to identify the best codes for analyzing RBCC engines and to document any potential shortcomings, not to demonstrate the merits or deficiencies of any particular engine design. Five cases representative of the operating regimes of typical RBCC engines were used as the basis of these comparisons. These included Mach 0 sea level static and Mach 1.0 and Mach 2.5 Air-Augmented-Rocket (AAR), Mach 4 subsonic combustion ramjet or dual-mode scramjet, and Mach 8 scramjet operating modes. Specification of a generic RBCC engine geometry and concomitant component operating efficiencies, bypass ratios, fuel/oxidizer/air equivalence ratios and flight dynamic pressures were provided. The engine included an air inlet, isolator duct, axial rocket motor/injector, axial wall fuel injectors, diverging combustor, and exit nozzle. Gaseous hydrogen was used as the fuel with the rocket portion of the system using a gaseous H2/O2 propellant system to avoid cryogenic issues. The results of the workshop, even after post-workshop adjudication of differences, were surprising. They showed that the codes predicted essentially the same performance at the Mach 0 and I conditions, but progressively diverged from a common value (for example, for fuel specific impulse, Isp) as the flight Mach number increased, with the largest differences at Mach 8. The example cases and results are compared and discussed in this paper.

  17. Health effects of subchronic inhalation exposure to gasoline engine exhaust.

    Science.gov (United States)

    Reed, M D; Barrett, E G; Campen, M J; Divine, K K; Gigliotti, A P; McDonald, J D; Seagrave, J C; Mauderly, J L; Seilkop, S K; Swenberg, J A

    2008-10-01

    Gasoline engine emissions are a ubiquitous source of exposure to complex mixtures of particulate matter (PM) and non-PM pollutants; yet their health hazards have received little study in comparison with those of diesel emissions. As a component of the National Environmental Respiratory Center (NERC) multipollutant research program, F344 and SHR rats and A/J, C57BL/6, and BALBc mice were exposed 6 h/day, 7 days/week for 1 week to 6 months to exhaust from 1996 General Motors 4.3-L engines burning national average fuel on a simulated urban operating cycle. Exposure groups included whole exhaust diluted 1:10, 1:15, or 1:90, filtered exhaust at the 1:10 dilution, or clean air controls. Evaluations included organ weight, histopathology, hematology, serum chemistry, bronchoalveolar lavage, cardiac electrophysiology, micronuclei in circulating cells, DNA methylation and oxidative injury, clearance of Pseudomonas aeruginosa from the lung, and development of respiratory allergic responses to ovalbumin. Among the 120 outcome variables, only 20 demonstrated significant exposure effects. Several statistically significant effects appeared isolated and were not supported by related variables. The most coherent and consistent effects were those related to increased red blood cells, interpreted as likely to have resulted from exposure to 13-107 ppm carbon monoxide. Other effects supported by multiple variables included mild lung irritation and depression of oxidant production by alveolar macrophages. The lowest exposure level caused no significant effects. Because only 6 of the 20 significant effects appeared to be substantially reversed by PM filtration, the majority of effects were apparently caused by non-PM components of exhaust.

  18. Using Innovative Technologies for Manufacturing Rocket Engine Hardware

    Science.gov (United States)

    Betts, E. M.; Eddleman, D. E.; Reynolds, D. C.; Hardin, N. A.

    2011-01-01

    Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As the United States enters into the next space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, rapid manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on NASA s Space Launch System (SLS) upper stage engine, J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator (GG) discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using a workhorse gas generator (WHGG) test fixture at MSFC's East Test Area, the duct was subjected to extreme J-2X hot gas environments during 7 tests for a total of 537 seconds of hot-fire time. The duct underwent extensive post-test evaluation and showed no signs of degradation. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

  19. Exhaust Gas Emissions from a Rotating Detonation-wave Engine

    Science.gov (United States)

    Kailasanath, Kazhikathra; Schwer, Douglas

    2015-11-01

    Rotating detonation-wave engines (RDE) are a form of continuous detonation-wave engines. They potentially provide further gains in performance than an intermittent or pulsed detonation-wave engine (PDE). The overall flow field in an idealized RDE, primarily consisting of two concentric cylinders, has been discussed in previous meetings. Because of the high pressures involved and the lack of adequate reaction mechanisms for this regime, previous simulations have typically used simplified chemistry models. However, understanding the exhaust species concentrations in propulsion devices is important for both performance considerations as well as estimating pollutant emissions. Progress towards addressing this need will be discussed in this talk. In this approach, an induction parameter model is used for simulating the detonation but a more detailed finite-chemistry model including NOx chemistry is used in the expansion flow region, where the pressures are lower and the uncertainties in the chemistry model are greatly reduced. Results show that overall radical concentrations in the exhaust flow are substantially lower than from earlier predictions with simplified models. The performance of a baseline hydrogen/air RDE increased from 4940 s to 5000 s with the expansion flow chemistry, due to recombination of radicals and more production of H2O, resulting in additional heat release. Work sponsored by the Office of Naval Research.

  20. Modelling and Operation of Diesel Engine Exhaust Gas Cleaning Systems

    DEFF Research Database (Denmark)

    Åberg, Andreas

    . Challenges with this technology include dosing the appropriate amount of urea to reach sufficient NOx conversion, while at the same time keeping NH3- slip from the exhaust system below the legislation. This requires efficient control algorithms. The focus of this thesis is modelling and control of the SCR...... parameters were estimated using bench-scale monolith isothermal data. Validation was done by simulating the out-put from a full-scale SCR monolith that was treating real engine gases from the European Transient Cycle (ETC). Results showed that the models were successfully calibrated, and that some......, and simulating the system....

  1. Development Testing of 1-Newton ADN-Based Rocket Engines

    Science.gov (United States)

    Anflo, K.; Gronland, T.-A.; Bergman, G.; Nedar, R.; Thormählen, P.

    2004-10-01

    With the objective to reduce operational hazards and improve specific and density impulse as compared with hydrazine, the Research and Development (R&D) of a new monopropellant for space applications based on AmmoniumDiNitramide (ADN), was first proposed in 1997. This pioneering work has been described in previous papers1,2,3,4 . From the discussion above, it is clear that cost savings as well as risk reduction are the main drivers to develop a new generation of reduced hazard propellants. However, this alone is not enough to convince a spacecraft builder to choose a new technology. Cost, risk and schedule reduction are good incentives, but a spacecraft supplier will ask for evidence that this new propulsion system meets a number of requirements within the following areas: This paper describes the ongoing effort to develop a storable liquid monopropellant blend, based on AND, and its specific rocket engines. After building and testing more than 20 experimental rocket engines, the first Engineering Model (EM-1) has now accumulated more than 1 hour of firing-time. The results from test firings have validated the design. Specific impulse, combustion stability, blow-down capability and short pulse capability are amongst the requirements that have been demonstrated. The LMP-103x propellant candidate has been stored for more than 1 year and initial material compatibility screening and testing has started. 1. Performance &life 2. Impact on spacecraft design &operation 3. Flight heritage Hereafter, the essential requirements for some of these areas are outlined. These issues are discussed in detail in a previous paper1 . The use of "Commercial Of The Shelf" (COTS) propulsion system components as much as possible is essential to minimize the overall cost, risk and schedule. This leads to the conclusion that the Technology Readiness Level (TRL) 5 has been reached for the thruster and propellant. Furthermore, that the concept of ADN-based propulsion is feasible.

  2. Using Innovative Techniques for Manufacturing Rocket Engine Hardware

    Science.gov (United States)

    Betts, Erin M.; Reynolds, David C.; Eddleman, David E.; Hardin, Andy

    2011-01-01

    Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As we enter into a new space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt new and innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using the Workhorse Gas Generator (WHGG) test setup at MSFC?s East Test Area test stand 116, the duct was subject to extreme J-2X gas generator environments and endured a total of 538 seconds of hot-fire time. The duct survived the testing and was inspected after the test. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended.

  3. Software for Preprocessing Data from Rocket-Engine Tests

    Science.gov (United States)

    Cheng, Chiu-Fu

    2004-01-01

    Three computer programs have been written to preprocess digitized outputs of sensors during rocket-engine tests at Stennis Space Center (SSC). The programs apply exclusively to the SSC E test-stand complex and utilize the SSC file format. The programs are the following: Engineering Units Generator (EUGEN) converts sensor-output-measurement data to engineering units. The inputs to EUGEN are raw binary test-data files, which include the voltage data, a list identifying the data channels, and time codes. EUGEN effects conversion by use of a file that contains calibration coefficients for each channel. QUICKLOOK enables immediate viewing of a few selected channels of data, in contradistinction to viewing only after post-test processing (which can take 30 minutes to several hours depending on the number of channels and other test parameters) of data from all channels. QUICKLOOK converts the selected data into a form in which they can be plotted in engineering units by use of Winplot (a free graphing program written by Rick Paris). EUPLOT provides a quick means for looking at data files generated by EUGEN without the necessity of relying on the PV-WAVE based plotting software.

  4. Construction and design of solid-propellant rocket engines. Konstruktsiia i proektirovanie raketnykh dvigatelei tverdogo topliva

    Energy Technology Data Exchange (ETDEWEB)

    Fakhrutdinov, I.K.; Kotel' nikov, A.V.

    1987-01-01

    Methods for assessing the durability of different components of solid-propellant rocket engines are presented. The following aspects of engine development are discussed: task formulation, parameter calculation, construction scheme selection, materials, and durability assessment. 45 references.

  5. Approaches to Low Fuel Regression Rate in Hybrid Rocket Engines

    Directory of Open Access Journals (Sweden)

    Dario Pastrone

    2012-01-01

    Full Text Available Hybrid rocket engines are promising propulsion systems which present appealing features such as safety, low cost, and environmental friendliness. On the other hand, certain issues hamper the development hoped for. The present paper discusses approaches addressing improvements to one of the most important among these issues: low fuel regression rate. To highlight the consequence of such an issue and to better understand the concepts proposed, fundamentals are summarized. Two approaches are presented (multiport grain and high mixture ratio which aim at reducing negative effects without enhancing regression rate. Furthermore, fuel material changes and nonconventional geometries of grain and/or injector are presented as methods to increase fuel regression rate. Although most of these approaches are still at the laboratory or concept scale, many of them are promising.

  6. Failure characteristics analysis and fault diagnosis for liquid rocket engines

    CERN Document Server

    Zhang, Wei

    2016-01-01

    This book concentrates on the subject of health monitoring technology of Liquid Rocket Engine (LRE), including its failure analysis, fault diagnosis and fault prediction. Since no similar issue has been published, the failure pattern and mechanism analysis of the LRE from the system stage are of particular interest to the readers. Furthermore, application cases used to validate the efficacy of the fault diagnosis and prediction methods of the LRE are different from the others. The readers can learn the system stage modeling, analyzing and testing methods of the LRE system as well as corresponding fault diagnosis and prediction methods. This book will benefit researchers and students who are pursuing aerospace technology, fault detection, diagnostics and corresponding applications.

  7. Integrated System Health Management (ISHM) Implementation in Rocket Engine Testing

    Science.gov (United States)

    Figueroa, Fernando; Morris, Jon; Turowski, Mark; Franzl, Richard; Walker, Mark; Kapadia, Ravi; Venkatesh, Meera

    2010-01-01

    A pilot operational ISHM capability has been implemented for the E-2 Rocket Engine Test Stand (RETS) and a Chemical Steam Generator (CSG) test article at NASA Stennis Space Center. The implementation currently includes an ISHM computer and a large display in the control room. The paper will address the overall approach, tools, and requirements. It will also address the infrastructure and architecture. Specific anomaly detection algorithms will be discussed regarding leak detection and diagnostics, valve validation, and sensor validation. It will also describe development and use of a Health Assessment Database System (HADS) as a repository for measurements, health, configuration, and knowledge related to a system with ISHM capability. It will conclude with a discussion of user interfaces, and a description of the operation of the ISHM system prior, during, and after testing.

  8. Critical Performance of Turbopump Mechanical Elements for Rocket Engine

    Science.gov (United States)

    Takada, Satoshi; Kikuchi, Masataka; Sudou, Takayuki; Iwasaki, Fumiya; Watanabe, Yoshiaki; Yoshida, Makoto

    It is generally acknowledged that bearings and axial seals have a tendency to go wrong compared with other rocket engine elements. And when those components have malfunction, missions scarcely succeed. However, fundamental performance (maximum rotational speed, minimum flow rate, power loss, durability, etc.) of those components has not been grasped yet. Purpose of this study is to grasp a critical performance of mechanical seal and hybrid ball bearing of turbopump. In this result, it was found that bearing outer race temperature and bearing coolant outlet temperature changed along saturation line of liquid hydrogen when flow rate was decreased under critical pressure. And normal operation of bearing was possible under conditions of more than 70,000 rpm of rotational speed and more than 0.2 liter/s of coolant flow rate. Though friction coefficient of seal surface increased several times of original value after testing, the seal showed a good performance same as before.

  9. Potential of secondary aerosol formation from Chinese gasoline engine exhaust.

    Science.gov (United States)

    Du, Zhuofei; Hu, Min; Peng, Jianfei; Guo, Song; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Qin, Yanhong; Niu, He; Li, Mengren; Yang, Yudong; Lu, Sihua; Wu, Yusheng; Shao, Min; Shuai, Shijin

    2018-04-01

    Light-duty gasoline vehicles have drawn public attention in China due to their significant primary emissions of particulate matter and volatile organic compounds (VOCs). However, little information on secondary aerosol formation from exhaust for Chinese vehicles and fuel conditions is available. In this study, chamber experiments were conducted to quantify the potential of secondary aerosol formation from the exhaust of a port fuel injection gasoline engine. The engine and fuel used are common in the Chinese market, and the fuel satisfies the China V gasoline fuel standard. Substantial secondary aerosol formation was observed during a 4-5hr simulation, which was estimated to represent more than 10days of equivalent atmospheric photo-oxidation in Beijing. As a consequence, the extreme case secondary organic aerosol (SOA) production was 426±85mg/kg-fuel, with high levels of precursors and OH exposure. The low hygroscopicity of the aerosols formed inside the chamber suggests that SOA was the dominant chemical composition. Fourteen percent of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatile organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reductions of emissions of aerosol precursor gases from vehicles are essential to mediate pollution in China. Copyright © 2017. Published by Elsevier B.V.

  10. CFD Analysis of Square Flow Channel in Thermal Engine Rocket Adventurer for Space Nuclear Application

    International Nuclear Information System (INIS)

    Nam, S. H.; Suh, K. Y.; Kang, S. G.

    2008-01-01

    Solar system exploration relying on chemical rockets suffers from long trip time and high cost. In this regard nuclear propulsion is an attractive option for space exploration. The performance of Nuclear Thermal Rocket (NTR) is more than twice that of the best chemical rocket. Resorting to the pure hydrogen (H 2 ) propellant the NTRs can possibly achieve as high as 1,000 s of specific impulse (I sp ) representing the ratio of the thrust over the fuel consumption rate, as compared to only 425 s of H 2 /O 2 rockets. If we reflect on the mission to Mars, NTRs would reduce the round trip time to less than 300 days, instead of over 600 days with chemical rockets. This work presents CFD analysis of one Fuel Element (FE) of Thermal Engine Rocket Adventurer (TERA). In particular, one Square Flow Channel (SFC) is analyzed in Square Lattice Honeycomb (SLHC) fuel to examine the effects of mass flow rate on rocket performance

  11. Optimization of the rocket mode trajectory in a rocket based combined cycle (RBCC) engine powered SSTO vehicle

    Science.gov (United States)

    Foster, Richard W.

    1989-07-01

    The application of rocket-based combined cycle (RBCC) engines to booster-stage propulsion, in combination with all-rocket second stages in orbital-ascent missions, has been studied since the mid-1960s; attention is presently given to the case of the 'ejector scramjet' RBCC configuration's application to SSTO vehicles. While total mass delivered to initial orbit is optimized at Mach 20, payload delivery capability to initial orbit optimizes at Mach 17, primarily due to the reduction of hydrogen fuel tankage structure, insulation, and thermal protection system weights.

  12. Exhaust gas turbocharger for internal combustion engines. Abgasturbolader fuer Brennkraftmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Behnert, R.; Dommes, W.; Gerwig, W.

    1982-01-21

    The invention aimes at the heat protection of a turbocharger for internal combustion engines. The turbine is feeded with exhaust gas and drives the shaft of a compressor. For resolving this problem a thermal shield has been installed on the backside of the turbine. The shaft is sealed with an elastic gasket ring. This gasket avoids the deposition of dust and dirt. As a consequence of this constructive measure a growth of tinder and oxides can be avoided as well as the deposition of dirt. A constant reflection factor is ensured. The thermal shield can be manufactured of thin sheet with a nickel surface and can fastened with distance pieces on the backside of the turbine case. Furthermore it is possible to use a ceramic heat shield.

  13. Occupational exposure to diesel engine exhaust and serum cytokine levels.

    Science.gov (United States)

    Dai, Yufei; Ren, Dianzhi; Bassig, Bryan A; Vermeulen, Roel; Hu, Wei; Niu, Yong; Duan, Huawei; Ye, Meng; Meng, Tao; Xu, Jun; Bin, Ping; Shen, Meili; Yang, Jufang; Fu, Wei; Meliefste, Kees; Silverman, Debra; Rothman, Nathaniel; Lan, Qing; Zheng, Yuxin

    2018-03-01

    The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response using data from a cross-sectional molecular epidemiology study of 41 diesel engine testing workers and 46 unexposed controls. Repeated personal exposure measurements of PM 2.5 and other DEE constituents were taken for the diesel engine testing workers before blood collection. Serum levels of six inflammatory biomarkers including interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1β, and monocyte chemotactic protein (MCP)-1 were analyzed in all subjects. Compared to unexposed controls, concentrations of MIP-1β were significantly reduced by ∼37% in DEE exposed workers (P 397 µg/m 3 ) compared to unexposed controls. Further, significant inverse exposure-response relationships for IL-8 and MCP-1 were also found in relation to increasing PM 2.5 levels among the DEE exposed workers. Given that IL-8, MIP-1β, and MCP-1 are chemokines that play important roles in recruitment of immunocompetent cells for immune defense and tumor cell clearance, the observed lower levels of these markers with increasing PM 2.5 exposure may provide insight into the mechanism by which DEE promotes lung cancer. Environ. Mol. Mutagen. 59:144-150, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Modification of Roberts' Theory for Rocket Exhaust Plumes Eroding Lunar Soil

    Science.gov (United States)

    Metzger, Philip T.; Lane, John E.; Immer, Christopher D.

    2008-01-01

    Roberts' model of lunar soil erosion beneath a landing rocket has been updated in several ways to predict the effects of future lunar landings. The model predicts, among other things, the number of divots that would result on surrounding hardware due to the impact of high velocity particulates, the amount and depth of surface material removed, the volume of ejected soil, its velocity, and the distance the particles travel on the Moon. The results are compared against measured results from the Apollo program and predictions are made for mitigating the spray around a future lunar outpost.

  15. NOx Reduction Technology in Diesel Engine Exhaust by the Plasmatron

    International Nuclear Information System (INIS)

    Joa, Sang Beom

    2008-02-01

    The diesel vehicle is relatively superior to gasoline vehicle on the fuel consumption, durability and combustion efficiency. However, exhaust emissions from diesel vehicles are known to be harmful to human health and environment. An experimental study of the diesel fuel reformation by a plasmatron and diesel engine exhaust cleaning by means of plasma chemical pretreatment of fuel is described. Plasma chemical reformation of fuel was carried by a DC arc plasmatron that was fabricated to increase an ability of the gas activation. Some portion of the fuel was activated in an arc discharge and turned into the hydrogen-rich synthesis gas. The yield of reformation for the diesel fuel showed 80 % ∼ 100 % when the small quantities of fuel (flow rate up to about 6 cc/min) were reformed. The regulation for an emission from the diesel vehicle is getting more stringent, the research in the field of the in-cylinder processing technologies (pretreatment) becomes more important issue as well as the catalyst after-treatment. The used high durability plasmatron has the characteristics of low contamination level, low anode erosion rate, low plasma temperature, and effective activation of the process gas. The developed fuel reformation system with the plasmatron was connected to the air feeding inlet sleeve of the diesel engine Kookje 3T90LT-AC (Korea) in order to study the reduction of NOx content in the engine's emission. Tubular reformation chamber was connected to the engine through the heat exchanger DOVER B10Hx20/1P-SC-S. Its cooling jacket was connected in series with the cooling system of the plasmatron. At the exit of this device gas temperature did not exceed ∼40 .deg. C at plasmatron power up to 1.5 kW which seemed quite acceptable. Gas composition was studied here using RBR-Ecom KD gas analyzer. The design of the DC arc plasmatron applied for the plasma chemical fuel reformation was improved boosting the degree of fuel-air mixture activation that provided the

  16. Reusable Rocket Engine Advanced Health Management System. Architecture and Technology Evaluation: Summary

    Science.gov (United States)

    Pettit, C. D.; Barkhoudarian, S.; Daumann, A. G., Jr.; Provan, G. M.; ElFattah, Y. M.; Glover, D. E.

    1999-01-01

    In this study, we proposed an Advanced Health Management System (AHMS) functional architecture and conducted a technology assessment for liquid propellant rocket engine lifecycle health management. The purpose of the AHMS is to improve reusable rocket engine safety and to reduce between-flight maintenance. During the study, past and current reusable rocket engine health management-related projects were reviewed, data structures and health management processes of current rocket engine programs were assessed, and in-depth interviews with rocket engine lifecycle and system experts were conducted. A generic AHMS functional architecture, with primary focus on real-time health monitoring, was developed. Fourteen categories of technology tasks and development needs for implementation of the AHMS were identified, based on the functional architecture and our assessment of current rocket engine programs. Five key technology areas were recommended for immediate development, which (1) would provide immediate benefits to current engine programs, and (2) could be implemented with minimal impact on the current Space Shuttle Main Engine (SSME) and Reusable Launch Vehicle (RLV) engine controllers.

  17. Study on the design of inlet and exhaust system of a stationary internal combustion engine

    International Nuclear Information System (INIS)

    Kesgin, Ugur

    2005-01-01

    The design and operational variables of inlet and exhaust systems are decisive to determine overall engine performance. The best engine overall performance can be obtained by proper design of the engine inlet and exhaust systems and by matching the correct turbocharger to the engine. This paper presents the results of investigations to design the inlet and exhaust systems of a stationary natural gas engine family. To do this, a computational model is verified in which zero dimensional phenomena within the cylinder and one dimensional phenomena in the engine inlet and exhaust systems are used. Using this engine model, the effects of the parameters of the inlet and exhaust systems on the engine performance are obtained. In particular, the following parameters are chosen: valve timing, valve diameter, valve lift profiles, diameter of the exhaust manifold, inlet and exhaust pipe lengths, and geometry of pipe junctions. Proper sizing of the inlet and exhaust pipe systems is achieved very precisely by these investigations. Also, valve timing is tuned by using the results obtained in this study. In general, a very high improvement potential for the engines studied here is presented

  18. Performance of an Axisymmetric Rocket Based Combined Cycle Engine During Rocket Only Operation Using Linear Regression Analysis

    Science.gov (United States)

    Smith, Timothy D.; Steffen, Christopher J., Jr.; Yungster, Shaye; Keller, Dennis J.

    1998-01-01

    The all rocket mode of operation is shown to be a critical factor in the overall performance of a rocket based combined cycle (RBCC) vehicle. An axisymmetric RBCC engine was used to determine specific impulse efficiency values based upon both full flow and gas generator configurations. Design of experiments methodology was used to construct a test matrix and multiple linear regression analysis was used to build parametric models. The main parameters investigated in this study were: rocket chamber pressure, rocket exit area ratio, injected secondary flow, mixer-ejector inlet area, mixer-ejector area ratio, and mixer-ejector length-to-inlet diameter ratio. A perfect gas computational fluid dynamics analysis, using both the Spalart-Allmaras and k-omega turbulence models, was performed with the NPARC code to obtain values of vacuum specific impulse. Results from the multiple linear regression analysis showed that for both the full flow and gas generator configurations increasing mixer-ejector area ratio and rocket area ratio increase performance, while increasing mixer-ejector inlet area ratio and mixer-ejector length-to-diameter ratio decrease performance. Increasing injected secondary flow increased performance for the gas generator analysis, but was not statistically significant for the full flow analysis. Chamber pressure was found to be not statistically significant.

  19. A Hybrid approach for aeroacoustic analysis of the engine exhaust system

    OpenAIRE

    Sathyanarayana, Y; Munjal, ML

    2000-01-01

    This paper presents a new hybrid approach for prediction of noise radiation from engine exhaust systems. It couples the time domain analysis of the engine and the frequency domain analysis of the muffler, and has the advantages of both. In this approach, cylinder/cavity is analyzed in the time domain to calculate the exhaust mass flux history at the exhaust valve by means of the method of characteristics, avoiding the tedious procedure of interpolation at every mesh point and solving a number...

  20. Rocket Engine Turbine Blade Surface Pressure Distributions Experiment and Computations

    Science.gov (United States)

    Hudson, Susan T.; Zoladz, Thomas F.; Dorney, Daniel J.; Turner, James (Technical Monitor)

    2002-01-01

    Understanding the unsteady aspects of turbine rotor flow fields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with miniature surface mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in two respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. A three-dimensional unsteady Navier-Stokes analysis was also used to blindly predict the unsteady flow field in the turbine at the design operating conditions and at +15 degrees relative incidence to the first-stage rotor. The predicted time-averaged and unsteady pressure distributions show good agreement with the experimental data. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools are contributing significantly to current Space Launch Initiative turbine airflow test and blade surface pressure prediction efforts.

  1. Side branch absorber for exhaust manifold of two-stroke internal combustion engine

    Science.gov (United States)

    Harris, Ralph E [San Antonio, TX; Broerman, III, Eugene L.; Bourn, Gary D [Laramie, WY

    2011-01-11

    A method of improving scavenging operation of a two-stroke internal combustion engine. The exhaust pressure of the engine is analyzed to determine if there is a pulsation frequency. Acoustic modeling is used to design an absorber. An appropriately designed side branch absorber may be attached to the exhaust manifold.

  2. Diesel engine exhaust initiates a sequence of pulmonary and cardiovascular effects in rats

    NARCIS (Netherlands)

    Kooter, I.M.; Gerlofs-Nijland, M.E.; Boere, A.J.F.; Leseman, D.L.A.C.; Fokkens, P.H.B.; Spronk, H.M.H.; Frederix, K.; Ten Cate, H.; Knaapen, A.M.; Vreman, H.J.; Cassee, F.R.

    2010-01-01

    This study was designed to determine the sequence of events leading to cardiopulmonary effects following acute inhalation of diesel engine exhaust in rats. Rats were exposed for 2h to diesel engine exhaust (1.9mg/m3), and biological parameters related to antioxidant defense, inflammation,

  3. Recovery of Exhaust Waste Heat for ICE Using the Beta Type Stirling Engine

    OpenAIRE

    Aladayleh, Wail; Alahmer, Ali

    2015-01-01

    This paper investigates the potential of utilizing the exhaust waste heat using an integrated mechanical device with internal combustion engine for the automobiles to increase the fuel economy, the useful power, and the environment safety. One of the ways of utilizing waste heat is to use a Stirling engine. A Stirling engine requires only an external heat source as wasted heat for its operation. Because the exhaust gas temperature may reach 200 to 700°C, Stirling engine will work effectively....

  4. System Engineering and Technical Challenges Overcome in the J-2X Rocket Engine Development Project

    Science.gov (United States)

    Ballard, Richard O.

    2012-01-01

    Beginning in 2006, NASA initiated the J-2X engine development effort to develop an upper stage propulsion system to enable the achievement of the primary objectives of the Constellation program (CxP): provide continued access to the International Space Station following the retirement of the Space Station and return humans to the moon. The J-2X system requirements identified to accomplish this were very challenging and the time expended over the five years following the beginning of the J- 2X effort have been noteworthy in the development of innovations in both the fields for liquid rocket propulsion and system engineering.

  5. Multicamera High Dynamic Range High-Speed Video of Rocket Engine Tests and Launches

    Data.gov (United States)

    National Aeronautics and Space Administration — High-speed video recording of rocket engine tests has several challenges. The scenes that are imaged have both bright and dark regions associated with plume emission...

  6. Code Validation of CFD Heat Transfer Models for Liquid Rocket Engine Combustion Devices

    National Research Council Canada - National Science Library

    Coy, E. B

    2007-01-01

    .... The design of the rig and its capabilities are described. A second objective of the test rig is to provide CFD validation data under conditions relevant to liquid rocket engine thrust chambers...

  7. Exhaust gas concentration of CNG fuelled direct injection engine at MBT timing

    International Nuclear Information System (INIS)

    Hassan, M.K.; Aris, I.; Mahmod, S.; Sidek, R.

    2009-01-01

    Full text: This paper presents an experimental result of exhaust gas concentration of high compression engine fuelled with compressed natural gas (CNG) at maximum brake torque (MBT). The engine uses central direct injection (DI) technique to inject the CNG into the cylinder. The engine geometry bases on gasoline engine with 14:1 compression ratio and called CNGDI engine. The injectors are positioned within a certain degrees of spark plug location. The objective of the experiment is to study the influence and significant of MBT timing in CNGDI engine towards exhaust gases. The experimental tests were carried out using computer-controlled eddy-current dynamometer, which measures the CNGDI engine performance. At MBT region, exhaust gas concentration as such CO, HC, NO x , O 2 and CO 2 , were recorded and analyzed during the test using the Horiba analyzer. A closed loop wide band lambda sensor has been mounted at the exhaust manifold to indicate the oxygen level during the exercise. (author)

  8. Space shuttle with common fuel tank for liquid rocket booster and main engines (supertanker space shuttle)

    Science.gov (United States)

    Thorpe, Douglas G.

    1991-01-01

    An operation and schedule enhancement is shown that replaces the four-body cluster (Space Shuttle Orbiter (SSO), external tank, and two solid rocket boosters) with a simpler two-body cluster (SSO and liquid rocket booster/external tank). At staging velocity, the booster unit (liquid-fueled booster engines and vehicle support structure) is jettisoned while the remaining SSO and supertank continues on to orbit. The simpler two-bodied cluster reduces the processing and stack time until SSO mate from 57 days (for the solid rocket booster) to 20 days (for the liquid rocket booster). The areas in which liquid booster systems are superior to solid rocket boosters are discussed. Alternative and future generation vehicles are reviewed to reveal greater performance and operations enhancements with more modifications to the current methods of propulsion design philosophy, e.g., combined cycle engines, and concentric propellant tanks.

  9. Evaluation of carcinogenic hazard of diesel engine exhaust needs to consider revolutionary changes in diesel technology.

    Science.gov (United States)

    McClellan, Roger O; Hesterberg, Thomas W; Wall, John C

    2012-07-01

    Diesel engines, a special type of internal combustion engine, use heat of compression, rather than electric spark, to ignite hydrocarbon fuels injected into the combustion chamber. Diesel engines have high thermal efficiency and thus, high fuel efficiency. They are widely used in commerce prompting continuous improvement in diesel engines and fuels. Concern for health effects from exposure to diesel exhaust arose in the mid-1900s and stimulated development of emissions regulations and research to improve the technology and characterize potential health hazards. This included epidemiological, controlled human exposure, laboratory animal and mechanistic studies to evaluate potential hazards of whole diesel exhaust. The International Agency for Research on Cancer (1989) classified whole diesel exhaust as - "probably carcinogenic to humans". This classification stimulated even more stringent regulations for particulate matter that required further technological developments. These included improved engine control, improved fuel injection system, enhanced exhaust cooling, use of ultra low sulfur fuel, wall-flow high-efficiency exhaust particulate filters, exhaust catalysts, and crankcase ventilation filtration. The composition of New Technology Diesel Exhaust (NTDE) is qualitatively different and the concentrations of particulate constituents are more than 90% lower than for Traditional Diesel Exhaust (TDE). We recommend that future reviews of carcinogenic hazards of diesel exhaust evaluate NTDE separately from TDE. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES

    Energy Technology Data Exchange (ETDEWEB)

    Blau, Peter Julian [ORNL

    2009-11-01

    The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats

  11. LOX/Methane Regeneratively-Cooled Rocket Engine Development

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to advance the technologies required to build a subcritical regeneratively cooled liquid oxygen/methane rocket combustion chamber for...

  12. Nonlinear Longitudinal Mode Instability in Liquid Propellant Rocket Engine Preburners

    Science.gov (United States)

    Sims, J. D. (Technical Monitor); Flandro, Gary A.; Majdalani, Joseph; Sims, Joseph D.

    2004-01-01

    Nonlinear pressure oscillations have been observed in liquid propellant rocket instability preburner devices. Unlike the familiar transverse mode instabilities that characterize primary combustion chambers, these oscillations appear as longitudinal gas motions with frequencies that are typical of the chamber axial acoustic modes. In several respects, the phenomenon is similar to longitudinal mode combustion instability appearing in low-smoke solid propellant motors. An important feature is evidence of steep-fronted wave motions with very high amplitude. Clearly, gas motions of this type threaten the mechanical integrity of associated engine components and create unacceptably high vibration levels. This paper focuses on development of the analytical tools needed to predict, diagnose, and correct instabilities of this type. For this purpose, mechanisms that lead to steep-fronted, high-amplitude pressure waves are described in detail. It is shown that such gas motions are the outcome of the natural steepening process in which initially low amplitude standing acoustic waves grow into shock-like disturbances. The energy source that promotes this behavior is a combination of unsteady combustion energy release and interactions with the quasi-steady mean chamber flow. Since shock waves characterize the gas motions, detonation-like mechanisms may well control the unsteady combustion processes. When the energy gains exceed the losses (represented mainly by nozzle and viscous damping), the waves can rapidly grow to a finite amplitude limit cycle. Analytical tools are described that allow the prediction of the limit cycle amplitude and show the dependence of this wave amplitude on the system geometry and other design parameters. This information can be used to guide corrective procedures that mitigate or eliminate the oscillations.

  13. Occupational exposure to diesel engine exhaust: a literature review.

    Science.gov (United States)

    Pronk, Anjoeka; Coble, Joseph; Stewart, Patricia A

    2009-07-01

    Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO(2)). Information on determinants of exposure was abstracted. In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO(2) measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles and 68% from off-road vehicles (30% mining, 15% railroad, and 22% others). Highest levels were reported for enclosed underground work sites in which heavy equipment is used: mining, mine maintenance, and construction (EC: 27-658 microg/m(3)). Intermediate exposure levels were generally reported for above-ground (semi-) enclosed areas in which smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: ECunderground mining and construction, intermediate for working in above-ground (semi-) enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population-based epidemiological studies and guide future exposure assessment efforts for industrial hygiene and epidemiological studies.

  14. 30 CFR 36.25 - Engine exhaust system.

    Science.gov (United States)

    2010-07-01

    ... (see § 36.23(b)(2)). (3) In lieu of a space-place flame arrester, an exhaust-gas cooling box or... exhaust system for convenient, temporary attachment of a pressure gage at a point suitable for measuring the total back pressure in the system. The connection also shall be suitable for temporary attachment...

  15. On the thermodynamics of waste heat recovery from internal combustion engine exhaust gas

    Science.gov (United States)

    Meisner, G. P.

    2013-03-01

    The ideal internal combustion (IC) engine (Otto Cycle) efficiency ηIC = 1-(1/r)(γ - 1) is only a function of engine compression ratio r =Vmax/Vmin and exhaust gas specific heat ratio γ = cP/cV. Typically r = 8, γ = 1.4, and ηIC = 56%. Unlike the Carnot Cycle where ηCarnot = 1-(TC/TH) for a heat engine operating between hot and cold heat reservoirs at TH and TC, respectively, ηIC is not a function of the exhaust gas temperature. Instead, the exhaust gas temperature depends only on the intake gas temperature (ambient), r, γ, cV, and the combustion energy. The ejected exhaust gas heat is thermally decoupled from the IC engine and conveyed via the exhaust system (manifold, pipe, muffler, etc.) to ambient, and the exhaust system is simply a heat engine that does no useful work. The maximum fraction of fuel energy that can be extracted from the exhaust gas stream as useful work is (1-ηIC) × ηCarnot = 32% for TH = 850 K (exhaust) and TC = 370 K (coolant). This waste heat can be recovered using a heat engine such as a thermoelectric generator (TEG) with ηTEG> 0 in the exhaust system. A combined IC engine and TEG system can generate net useful work from the exhaust gas waste heat with efficiency ηWH = (1-ηIC) × ηCarnot ×ηTEG , and this will increase the overall fuel efficiency of the total system. Recent improvements in TEGs yield ηTEG values approaching 15% giving a potential total waste heat conversion efficiency of ηWH = 4.6%, which translates into a fuel economy improvement approaching 5%. This work is supported by the US DOE under DE-EE0005432.

  16. Exhaust gas turbo-charger for internal combustion engines. Abgasturbolader fuer Brennkraftmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Behnert, R.

    1982-01-07

    The invention is concerned with a exhaust gas turbocharger for internal combustion engines. A turbine driving a compressor, is feeded with the exhaust gas. Intended is the over-temperature protection of the exhaust gas turbocharger. For this reason a ring shaped sheet with a well polished nickel surface, serves as thermal shield. A sealing avoids soiling of the turbine shaft. Due to the heat shielding effect no tinder, oxide or dirt deposition is possible. The heat reflection factor is constant.

  17. Recovery of Exhaust Waste Heat for ICE Using the Beta Type Stirling Engine

    Directory of Open Access Journals (Sweden)

    Wail Aladayleh

    2015-01-01

    Full Text Available This paper investigates the potential of utilizing the exhaust waste heat using an integrated mechanical device with internal combustion engine for the automobiles to increase the fuel economy, the useful power, and the environment safety. One of the ways of utilizing waste heat is to use a Stirling engine. A Stirling engine requires only an external heat source as wasted heat for its operation. Because the exhaust gas temperature may reach 200 to 700°C, Stirling engine will work effectively. The indication work, real shaft power and specific fuel consumption for Stirling engine, and the exhaust power losses for IC engine are calculated. The study shows the availability and possibility of recovery of the waste heat from internal combustion engine using Stirling engine.

  18. Effect of biodiesel blends on engine performance and exhaust emission for diesel dual fuel engine

    International Nuclear Information System (INIS)

    Mohsin, R.; Majid, Z.A.; Shihnan, A.H.; Nasri, N.S.; Sharer, Z.

    2014-01-01

    Highlights: • Engine and emission characteristics of biodiesel DDF engine system were measured. • Biodiesel DDF fuelled system produced high engine performance. • Lower hydrocarbons and carbon dioxide was emitted by biodiesel DDF system. • Biodiesel DDF produced slightly higher carbon monoxide and nitric oxides emission. - Abstract: Biodiesel derived from biomass is a renewable source of fuel. It is renovated to be the possible fuel to replace fossil derived diesel due to its properties and combustion characteristics. The integration of compressed natural gas (CNG) in diesel engine known as diesel dual fuel (DDF) system offered better exhaust emission thus become an attractive option for reducing the pollutants emitted from transportation fleets. In the present study, the engine performance and exhaust emission of HINO H07C DDF engine; fuelled by diesel, biodiesel, diesel–CNG, and biodiesel–CNG, were experimentally studied. Biodiesel and diesel fuelled engine system respectively generated 455 N m and 287 N m of torque. The horse power of biodiesel was found to be 10–20% higher compared to diesel. Biodiesel–CNG at 20% (B20-DDF) produced the highest engine torque compared to other fuel blends Biodiesel significantly increase the carbon monoxide (15–32%) and nitric oxides (6.67–7.03%) but in contrast reduce the unburned hydrocarbons (5.76–6.25%) and carbon dioxide (0.47–0.58%) emissions level. These results indicated that biodiesel could be used without any engine modifications as an alternative and environmentally friendly fuel especially the heavy transportation fleets

  19. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2015-01-01

    Full Text Available The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple.

  20. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part II Dynamic Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2016-01-01

    Full Text Available The second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment of the enthalpy flux of successive pressure pulses of the exhaust gas supplying the marine engine turbocompressor. General design assumptions are presented for the measuring and diagnostic system which makes use of a sheathed thermocouple installed in the engine exhaust gas manifold. The corrected thermal inertia of the thermocouple enables to reproduce a real time-history of exhaust gas temperature changes.

  1. Exhaust Gas Recirculation Control for Large Diesel Engines - Achievable Performance with SISO Design

    DEFF Research Database (Denmark)

    Hansen, Jakob Mahler; Blanke, Mogens; Niemann, Hans Henrik

    2013-01-01

    This paper investigates control possibilities for Exhaust Gas Recirculation (EGR) on large diesel engines. The goal is to reduce the amount of NOx in the exhaust gas by reducing the oxygen concentration available for combustion. Control limitations imposed by the system are assessed using linear...

  2. Effect of cooling the recirculated exhaust gases on diesel engine emissions

    International Nuclear Information System (INIS)

    Abu-Hamdeh, Nidal H.

    2003-01-01

    Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NO x ), carbon dioxide (CO 2 ) and carbon monoxide (CO). In addition, O 2 concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NO x ) and carbon dioxide (CO 2 ) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O 2 ) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NO x gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NO x but increased the particulate matter concentrations in the exhaust gases

  3. Effect of cooling the recirculated exhaust gases on diesel engine emissions

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Hamdeh, Nidal H. [Jordan Univ. of Science and Technology, Irbid (Jordan)

    2003-11-01

    Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NO{sub x}), carbon dioxide (CO{sub 2}) and carbon monoxide (CO). In addition, O{sub 2} concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NO{sub x}) and carbon dioxide (CO{sub 2}) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O{sub 2}) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NO{sub x} gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NO{sub x} but increased the particulate matter concentrations in the exhaust gases. (Author)

  4. Exhaust gas purifying system for an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Minami, H; Saito, Z

    1976-10-07

    The exhaust gas purification system is a so-called three-way catalytic converter. It consists of an oxidation converter, a reduction converter, or a thermal converter. An exhaust sensor made up of an oxygen sensor, a carbon sensor, a carbon monoxide sensor, hydrocarbon sensor, or a nitrogen peroxide sensor, tests the composition of the exhaust and controls the air-fuel feed system in dependence of the exhaust mixture in such a manner that in the intake system an air-fuel mixture is taken in which the stoichiometric air-fuel relation is produced. Moreover, a thermostatically controlled air intake device is built into the fuel injection system which supplies the air of the fuel injection system with a relatively consistent temperature.

  5. Two-dimensional motions of rockets

    International Nuclear Information System (INIS)

    Kang, Yoonhwan; Bae, Saebyok

    2007-01-01

    We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the descending parts of the trajectories tend to be gentler and straighter slopes than the ascending parts for relatively large launching angles due to the non-vanishing thrusts. We discuss the ranges, the maximum altitudes and the engine performances of the rockets. It seems that the exponential fuel exhaustion can be the most potent engine for the longest and highest flights

  6. Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Lee, Jeong Ik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    Nclear rockets improve the propellant efficiency more than twice compared to CRs and thus significantly reduce the propellant requirement. The superior efficiency of nuclear rockets is due to the combination of the huge energy density and a single low molecular weight propellant utilization. Nuclear Thermal Rockets (NTRs) are particularly suitable for manned missions to Mars because it satisfies a relatively high thrust as well as a high propellant efficiency. NTRs use thermal energy released from a nuclear fission reactor to heat a single low molecular weight propellant, i. e., Hydrogen (H{sub 2}) and then exhausted the extremely heated propellant through a thermodynamic nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub sp}) which represents the ratio of the thrust over the rate of propellant consumption. The difference of I{sub sp} makes over three times propellant savings of NTRs for a manned Mars mission compared to CRs. NTRs can also be configured to operate bimodally by converting the surplus nuclear energy to auxiliary electric power required for the operation of a spacecraft. Moreover, the concept and technology of NTRs are very simple, already proven, and safe. Thus, NTRs can be applied to various space missions such as solar system exploration, International Space Station (ISS) transport support, Near Earth Objects (NEOs) interception, etc. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The ROK has also begun the research for space nuclear systems as a volunteer of the international space race and a major world nuclear energy country. KANUTER is one of the advanced NTR engines currently under development at KAIST. This bimodal engine is operated in two modes of propulsion with 100 MW

  7. An historical perspective of the NERVA nuclear rocket engine technology program. Final Report

    International Nuclear Information System (INIS)

    Robbins, W.H.; Finger, H.B.

    1991-07-01

    Nuclear rocket research and development was initiated in the United States in 1955 and is still being pursued to a limited extent. The major technology emphasis occurred in the decade of the 1960s and was primarily associated with the Rover/NERVA Program where the technology for a nuclear rocket engine system for space application was developed and demonstrated. The NERVA (Nuclear Engine for Rocket Vehicle Application) technology developed twenty years ago provides a comprehensive and viable propulsion technology base that can be applied and will prove to be valuable for application to the NASA Space Exploration Initiative (SEI). This paper, which is historical in scope, provides an overview of the conduct of the NERVA Engine Program, its organization and management, development philosophy, the engine configuration, and significant accomplishments

  8. Theoretical Acoustic Absorber Design Approach for LOX/LCH4 Pintle Injector Rocket Engines

    Science.gov (United States)

    Candelaria, Jonathan

    Liquid rocket engines, or LREs, have served a key role in space exploration efforts. One current effort involves the utilization of liquid oxygen (LOX) and liquid methane (LCH4) LREs to explore Mars with in-situ resource utilization for propellant production. This on-site production of propellant will allow for greater payload allocation instead of fuel to travel to the Mars surface, and refueling of propellants to travel back to Earth. More useable mass yields a greater benefit to cost ratio. The University of Texas at El Paso's (UTEP) Center for Space Exploration and Technology Research Center (cSETR) aims to further advance these methane propulsion systems with the development of two liquid methane - liquid oxygen propellant combination rocket engines. The design of rocket engines, specifically liquid rocket engines, is complex in that many variables are present that must be taken into consideration in the design. A problem that occurs in almost every rocket engine development program is combustion instability, or oscillatory combustion. It can result in the destruction of the rocket, subsequent destruction of the vehicle and compromise the mission. These combustion oscillations can vary in frequency from 100 to 20,000 Hz or more, with varying effects, and occur from different coupling phenomena. It is important to understand the effects of combustion instability, its physical manifestations, how to identify the instabilities, and how to mitigate or dampen them. Linear theory methods have been developed to provide a mathematical understanding of the low- to mid-range instabilities. Nonlinear theory is more complex and difficult to analyze mathematically, therefore no general analytical method that yields a solution exists. With limited resources, time, and the advice of our NASA mentors, a data driven experimental approach utilizing quarter wave acoustic dampener cavities was designed. This thesis outlines the methodology behind the design of an acoustic

  9. SAFE testing nuclear rockets economically

    International Nuclear Information System (INIS)

    Howe, Steven D.; Travis, Bryan; Zerkle, David K.

    2003-01-01

    Several studies over the past few decades have recognized the need for advanced propulsion to explore the solar system. As early as the 1960s, Werner Von Braun and others recognized the need for a nuclear rocket for sending humans to Mars. The great distances, the intense radiation levels, and the physiological response to zero-gravity all supported the concept of using a nuclear rocket to decrease mission time. These same needs have been recognized in later studies, especially in the Space Exploration Initiative in 1989. One of the key questions that has arisen in later studies, however, is the ability to test a nuclear rocket engine in the current societal environment. Unlike the Rover/NERVA programs in the 1960s, the rocket exhaust can no longer be vented to the open atmosphere. As a consequence, previous studies have examined the feasibility of building a large-scale version of the Nuclear Furnace Scrubber that was demonstrated in 1971. We have investigated an alternative that would deposit the rocket exhaust along with any entrained fission products directly into the ground. The Subsurface Active Filtering of Exhaust, or SAFE, concept would allow variable sized engines to be tested for long times at a modest expense. A system overview, results of preliminary calculations, and cost estimates of proof of concept demonstrations are presented. The results indicate that a nuclear rocket could be tested at the Nevada Test Site for under $20 M

  10. Combustion dynamics in cryogenic rocket engines: Research programme at DLR Lampoldshausen

    Science.gov (United States)

    Hardi, Justin S.; Traudt, Tobias; Bombardieri, Cristiano; Börner, Michael; Beinke, Scott K.; Armbruster, Wolfgang; Nicolas Blanco, P.; Tonti, Federica; Suslov, Dmitry; Dally, Bassam; Oschwald, Michael

    2018-06-01

    The Combustion Dynamics group in the Rocket Propulsion Department at the German Aerospace Center (DLR), Lampoldshausen, strives to advance the understanding of dynamic processes in cryogenic rocket engines. Leveraging the test facilities and experimental expertise at DLR Lampoldshausen, the group has taken a primarily experimental approach to investigating transient flows, ignition, and combustion instabilities for over one and a half decades. This article provides a summary of recent achievements, and an overview of current and planned research activities.

  11. Working-cycle processes in solid-propellant rocket engines (Handbook). Rabochie protsessy v raketnykh dvigateliakh tverdogo topliva /Spravochnik/

    Energy Technology Data Exchange (ETDEWEB)

    Shishkov, A.A.; Panin, S.D.; Rumiantsev, B.V.

    1989-01-01

    Physical and mathematical models of processes taking place in solid-propellant rocket engines and gas generators are presented in a systematic manner. The discussion covers the main types of solid propellants, the general design and principal components of solid-propellant rocket engines, the combustion of a solid-propellant charge, thermodynamic calculation of combustion and outflow processes, and analysis of gasdynamic processes in solid-propellant rocket engines. 40 refs.

  12. Control-oriented modeling of two-stroke diesel engines with exhaust gas recirculation for marine applications

    OpenAIRE

    Llamas, Xavier; Eriksson, Lars

    2018-01-01

    Large marine two-stroke diesel engines are widely used as propulsion systems for shipping worldwide and are facing stricter NOx emission limits. Exhaust gas recirculation is introduced to these engines to reduce the produced combustion NOx to the allowed levels. Since the current number of engines built with exhaust gas recirculation is low and engine testing is very expensive, a powerful alternative for developing exhaust gas recirculation controllers for such engines is to use control-orien...

  13. Reduction of exhaust gas emission for marine diesel engine. Hakuyo engine no taisaku (hakuyo engine no mondaiten to tenbo)

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Y. (Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan))

    1992-05-05

    Since bunker fuel became extremely expensive through the first and second oil crisis, the share of steam turbines having lower thermal efficiency than diesel engines became less, and at present, almost all ships and vessels are equipped with Diesel engines. Also fuel consumption of a diesel engine has successfully been reduced by 24% in about 10 years, but the discharge of air pollutant in the exhaust gas has shown a trend of increase. Air pollutant in exhaust gas of marine engines which has not drawn attention so far has also begun attracting notice, and as marine traffic increases, some control of it will be made sooner or later. Hence economical and effective counter measures against exhaust gas are necessary. In this article, as measures for reducing NO {sub x}, discussions are made on water-emulsion fuel, humidification of air supply, multi-nozzle atomization, injection time delaying and SCR (selective catalitic reduction). Also measures for reducing SO {sub x} is commented upon and the continuation of superiority of Diesel engines in the future is predicted. 5 figs.

  14. An approach for exhaust gas energy recovery of internal combustion engine: Steam-assisted turbocharging

    International Nuclear Information System (INIS)

    Fu, Jianqin; Liu, Jingping; Deng, Banglin; Feng, Renhua; Yang, Jing; Zhou, Feng; Zhao, Xiaohuan

    2014-01-01

    Highlights: • The calculation method for SAT engine was developed and introduced. • SAT can effectively promote the low-speed performances of IC engine. • At 1500 r/min, intake pressure reaches target value and torque is increased by 25%. • The thermal efficiency of SAT engine only has a slight increase. - Abstract: An approach for IC engine exhaust gas energy recovery, named as steam-assisted turbocharging (SAT), is developed to assist the exhaust turbocharger. A steam generating plant is coupled to the exhaust turbocharged engine’s exhaust pipe, which uses the high-temperature exhaust gas to generate steam. The steam is injected into turbine inlet and used as the supplementary working medium for turbine. By this means, turbine output power and then boosting pressure can be promoted due to the increase of turbine working medium. To reveal the advantages and energy saving potentials of SAT, this concept was applied to an exhaust turbocharging engine, and a parameter analysis was carried out. Research results show that, SAT can effectively promote the low-speed performances of IC engine, and make the peak torque shift to low-speed area. At 1500 r/min, the intake gas pressure can reach the desired value and the torque can be increased by 25.0% over the exhaust turbocharging engine, while the pumping mean effective pressure (PMEP) and thermal efficiency only have a slight increase. At 1000 r/min, the improvement of IC engine performances is very limited due to the low exhaust gas energy

  15. Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases from Internal-Combustion Engines

    Science.gov (United States)

    Gerrish, Harold C; Tessmann, Arthur M

    1935-01-01

    The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.

  16. Hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, E.; Kawahara, N. [Okayama Univ., Okayama (Japan); Roy, M.M. [Rajshahi Univ. of Engineering and Technology, Rajshahi (Bangladesh)

    2009-07-01

    A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N{sub 2} dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution to the diesel fuel with zero smoke emissions. figs.

  17. Hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel

    International Nuclear Information System (INIS)

    Tomita, E.; Kawahara, N.; Roy, M.M.

    2009-01-01

    A hydrogen combustion and exhaust emissions in a supercharged gas engine ignited with micro pilot diesel fuel was discussed in this presentation. A schematic diagram of the experimental study was first presented. The single cylinder, water-cooled, supercharged test engine was illustrated. Results were presented for the following: fuel energy and energy share (hydrogen and diesel fuel); pressure history and rate of heat release; engine performance and exhaust emissions; effect of nitrogen dilution on heat value per cycle; effect of N 2 dilution on pressure history and rate of heat release; and engine performance and exhaust emissions. This presentation demonstrated that smooth and knock-free engine operation results from the use of hydrogen in a supercharged dual-fuel engine for leaner fuel-air equivalence ratios maintaining high thermal efficiency. It was possible to attain mor3 than 90 per cent hydrogen-energy substitution to the diesel fuel with zero smoke emissions. figs.

  18. A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends.

    Science.gov (United States)

    Damanik, Natalina; Ong, Hwai Chyuan; Tong, Chong Wen; Mahlia, Teuku Meurah Indra; Silitonga, Arridina Susan

    2018-06-01

    Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.

  19. CFD Analysis of Square Flow Channel in Thermal Engine Rocket Adventurer for Space Nuclear Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, S. H.; Suh, K. Y. [Seoul National University, Seoul (Korea, Republic of); Kang, S. G. [PHILOSOPHIA, Inc., Seoul (Korea, Republic of)

    2008-10-15

    Solar system exploration relying on chemical rockets suffers from long trip time and high cost. In this regard nuclear propulsion is an attractive option for space exploration. The performance of Nuclear Thermal Rocket (NTR) is more than twice that of the best chemical rocket. Resorting to the pure hydrogen (H{sub 2}) propellant the NTRs can possibly achieve as high as 1,000 s of specific impulse (I{sub sp}) representing the ratio of the thrust over the fuel consumption rate, as compared to only 425 s of H{sub 2}/O{sub 2} rockets. If we reflect on the mission to Mars, NTRs would reduce the round trip time to less than 300 days, instead of over 600 days with chemical rockets. This work presents CFD analysis of one Fuel Element (FE) of Thermal Engine Rocket Adventurer (TERA). In particular, one Square Flow Channel (SFC) is analyzed in Square Lattice Honeycomb (SLHC) fuel to examine the effects of mass flow rate on rocket performance.

  20. Computer Design Technology of the Small Thrust Rocket Engines Using CAE / CAD Systems

    Science.gov (United States)

    Ryzhkov, V.; Lapshin, E.

    2018-01-01

    The paper presents an algorithm for designing liquid small thrust rocket engine, the process of which consists of five aggregated stages with feedback. Three stages of the algorithm provide engineering support for design, and two stages - the actual engine design. A distinctive feature of the proposed approach is a deep study of the main technical solutions at the stage of engineering analysis and interaction with the created knowledge (data) base, which accelerates the process and provides enhanced design quality. The using multifunctional graphic package Siemens NX allows to obtain the final product -rocket engine and a set of design documentation in a fairly short time; the engine design does not require a long experimental development.

  1. Identification of Noise Sources During Rocket Engine Test Firings and a Rocket Launch Using a Microphone Phased-Array

    Science.gov (United States)

    Panda, Jayanta; Mosher, Robert N.; Porter, Barry J.

    2013-01-01

    A 70 microphone, 10-foot by 10-foot, microphone phased array was built for use in the harsh environment of rocket launches. The array was setup at NASA Wallops launch pad 0A during a static test firing of Orbital Sciences' Antares engines, and again during the first launch of the Antares vehicle. It was placed 400 feet away from the pad, and was hoisted on a scissor lift 40 feet above ground. The data sets provided unprecedented insight into rocket noise sources. The duct exit was found to be the primary source during the static test firing; the large amount of water injected beneath the nozzle exit and inside the plume duct quenched all other sources. The maps of the noise sources during launch were found to be time-dependent. As the engines came to full power and became louder, the primary source switched from the duct inlet to the duct exit. Further elevation of the vehicle caused spilling of the hot plume, resulting in a distributed noise map covering most of the pad. As the entire plume emerged from the duct, and the ondeck water system came to full power, the plume itself became the loudest noise source. These maps of the noise sources provide vital insight for optimization of sound suppression systems for future Antares launches.

  2. A combined thermodynamic cycle based on methanol dissociation for IC (internal combustion) engine exhaust heat recovery

    International Nuclear Information System (INIS)

    Fu, Jianqin; Liu, Jingping; Xu, Zhengxin; Ren, Chengqin; Deng, Banglin

    2013-01-01

    In this paper, a novel approach for exhaust heat recovery was proposed to improve IC (internal combustion) engine fuel efficiency and also to achieve the goal for direct usage of methanol as IC engine fuel. An open organic Rankine cycle system using methanol as working medium is coupled to IC engine exhaust pipe for exhaust heat recovery. In the bottom cycle, the working medium first undergoes dissociation and expansion processes, and is then directed back to IC engine as fuel. As the external bottom cycle and the IC engine main cycle are combined together, this scheme forms a combined thermodynamic cycle. Then, this concept was applied to a turbocharged engine, and the corresponding simulation models were built for both of the external bottom cycle and the IC engine main cycle. On this basis, the energy saving potential of this combined cycle was estimated by parametric analyses. Compared to the methanol vapor engine, IC engine in-cylinder efficiency has an increase of 1.4–2.1 percentage points under full load conditions, while the external bottom cycle can increase the fuel efficiency by 3.9–5.2 percentage points at the working pressure of 30 bar. The maximum improvement to the IC engine global fuel efficiency reaches 6.8 percentage points. - Highlights: • A combined thermodynamic cycle using methanol as working medium for IC engine exhaust heat recovery is proposed. • The external bottom cycle of exhaust heat recovery and IC engine working cycle are combined together. • IC engine fuel efficiency could be improved from both in-cylinder working cycle and external bottom cycle. • The maximum improvement to the IC engine global fuel efficiency reaches 6.8 percentage points at full load

  3. Generic methods for aero-engine exhaust emission prediction

    NARCIS (Netherlands)

    Shakariyants, S.A.

    2008-01-01

    In the thesis, generic methods have been developed for aero-engine combustor performance, combustion chemistry, as well as airplane aerodynamics, airplane and engine performance. These methods specifically aim to support diverse emission prediction studies coupled with airplane and engine

  4. New technology on Otto engines for reducing the exhaust emission toxicity

    International Nuclear Information System (INIS)

    Mikarovska, Vesna; Stojanovski, Vasko

    2003-01-01

    The exhaust emission from the Otto engines with internal combustion contains a lot of toxicant components for human being as well as for the surrounding. There are a lot of possibilities to realize the engine work with minimum emission of toxicant components. However, all solutions could not be racial, especially if the engine should work with minimum fuel consumption. The engineers look for the solutions where the reducing of the exhaust emission toxicity could be done with the total fuel utilization in the engine's cylinder, without additionally combustion in catalytic or thermal reactors. The paper describes the new technologies for detail investigation of the combustion processes and optimization of all influence parameters on exhaust gases emission. (Original)

  5. Equipment for heating the exhaust gases of internal combustion engines in order to improve afterburning

    Energy Technology Data Exchange (ETDEWEB)

    Masaki,

    1976-04-15

    The device described here serves to heat exhaust gases of internal combustion engines by heat exchange with hot gases and also, in cold engines, to raise the temperature of the fuel-air mixture drawn in by the engine. The device is installed next to the outlet opening of the engine. It consists of a burner to generate the hot gas, as well as a heat exchanger permitting heat supply to the exhaust gases and a hot-gas line leading to the intake line. Heating of the air is taken in leads to a better atomization of the mixture and thus to improved combustion. Heating of the exhaust gases improves afterburning. The burner generating the hot gas is shut off when the normal operational temperature of the engine is reached. The temperature is controlled by means of a temperature sensor installed in the device.

  6. Thermodynamic control-oriented modeling of cycle-to-cycle exhaust gas temperature in an HCCI engine

    International Nuclear Information System (INIS)

    Dehghani Firoozabadi, M.; Shahbakhti, M.; Koch, C.R.; Jazayeri, S.A.

    2013-01-01

    Highlights: • First thermodynamic model in the literature to predict exhaust temperature in HCCI engines. • The model can be used for integrated control of HCCI combustion and exhaust temperature. • The model is experimentally validated at over 300 steady state and transient conditions. • Results show a good agreement between predicted and measured exhaust temperatures. • Sensitivity of exhaust gas temperature to variation of engine variables is shown. - Abstract: Model-based control of Homogenous Charge Compression Ignition (HCCI) engine exhaust temperature is a viable solution to optimize efficiency of both engine and the exhaust aftertreatment system. Low exhaust temperature in HCCI engines can limit the abatement of hydrocarbon (HC) and carbon monoxide (CO) emissions in an exhaust aftertreatment system. A physical–empirical model is described for control of exhaust temperature in HCCI engines. This model captures cycle-to-cycle dynamics affecting exhaust temperature and is based on thermodynamic relations and semi-empirical correlations. It incorporates intake and exhaust gas flow dynamics, residual gas mixing, and fuel burn rate and is validated with experimental data from a single cylinder engine at over 300 steady state and transient conditions. The validation results indicate a good agreement between predicted and measured exhaust gas temperature

  7. Rocket Science: The Shuttle's Main Engines, though Old, Are not Forgotten in the New Exploration Initiative

    Science.gov (United States)

    Covault, Craig

    2005-01-01

    The Space Shuttle Main Engine (SSME), developed 30 years ago, remains a strong candidate for use in the new Exploration Initiative as part of a shuttle-derived heavy-lift expendable booster. This is because the Boeing-Rocket- dyne man-rated SSME remains the most highly efficient liquid rocket engine ever developed. There are only enough parts for 12-15 existing SSMEs, however, so one NASA option is to reinitiate SSME production to use it as a throw-away, as opposed to a reusable, powerplant for NASA s new heavy-lift booster.

  8. Computational Fluid Dynamics Analysis Method Developed for Rocket-Based Combined Cycle Engine Inlet

    Science.gov (United States)

    1997-01-01

    Renewed interest in hypersonic propulsion systems has led to research programs investigating combined cycle engines that are designed to operate efficiently across the flight regime. The Rocket-Based Combined Cycle Engine is a propulsion system under development at the NASA Lewis Research Center. This engine integrates a high specific impulse, low thrust-to-weight, airbreathing engine with a low-impulse, high thrust-to-weight rocket. From takeoff to Mach 2.5, the engine operates as an air-augmented rocket. At Mach 2.5, the engine becomes a dual-mode ramjet; and beyond Mach 8, the rocket is turned back on. One Rocket-Based Combined Cycle Engine variation known as the "Strut-Jet" concept is being investigated jointly by NASA Lewis, the U.S. Air Force, Gencorp Aerojet, General Applied Science Labs (GASL), and Lockheed Martin Corporation. Work thus far has included wind tunnel experiments and computational fluid dynamics (CFD) investigations with the NPARC code. The CFD method was initiated by modeling the geometry of the Strut-Jet with the GRIDGEN structured grid generator. Grids representing a subscale inlet model and the full-scale demonstrator geometry were constructed. These grids modeled one-half of the symmetric inlet flow path, including the precompression plate, diverter, center duct, side duct, and combustor. After the grid generation, full Navier-Stokes flow simulations were conducted with the NPARC Navier-Stokes code. The Chien low-Reynolds-number k-e turbulence model was employed to simulate the high-speed turbulent flow. Finally, the CFD solutions were postprocessed with a Fortran code. This code provided wall static pressure distributions, pitot pressure distributions, mass flow rates, and internal drag. These results were compared with experimental data from a subscale inlet test for code validation; then they were used to help evaluate the demonstrator engine net thrust.

  9. Examination of Internally and Externally Coated Cr3C2 Exhaust Pipe of a Diesel Engine via Plasma Spray Method

    OpenAIRE

    H. Hazar; S. Sap

    2017-01-01

    In this experimental study; internal and external parts of an exhaust pipe were coated with a chromium carbide (Cr3C2) material having a thickness of 100 micron by using the plasma spray method. A diesel engine was used as the test engine. Thus, the results of continuing chemical reaction in coated and uncoated exhaust pipes were investigated. Internally and externally coated exhaust pipe was compared with the standard exhaust system. External heat transfer occurring as a result of coating th...

  10. Exhaust emissions of DI diesel engine using unconventional fuels

    Science.gov (United States)

    Sudrajad, Agung; Ali, Ismail; Hamdan, Hazmie; Hamzah, Mohd. Herzwan

    2012-06-01

    Optimization of using waste plastic and tire disposal fuel on diesel engine were observed. The experimental project was comparison between using both of unconventional fuel and base diesel fuel. The engine experiment was conducted with YANMAR TF120 single cylinder four stroke diesel engine set-up at variable engine speed at 2100, 1900, 1700, 1500 and 1300 rpm. The data have been taken at each point of engine speed during the stabilized engine-operating regime. Measurement of emissions parameters at different engine speed conditions have generally indicated lower in emission COfor waste plastic fuel, lower NOx for tire disposal fuel and lower SOx for diesel fuel.

  11. Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

    Science.gov (United States)

    Thomas, Matthew E.; Bossard, John A.; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

    2001-01-01

    The fiber optically coupled laser ignition approach summarized is under consideration for use in igniting bi-propellant rocket thrust chambers. This laser ignition approach is based on a novel dual pulse format capable of effectively increasing laser generated plasma life times up to 1000 % over conventional laser ignition methods. In the dual-pulse format tinder consideration here an initial laser pulse is used to generate a small plasma kernel. A second laser pulse that effectively irradiates the plasma kernel follows this pulse. Energy transfer into the kernel is much more efficient because of its absorption characteristics thereby allowing the kernel to develop into a much more effective ignition source for subsequent combustion processes. In this research effort both single and dual-pulse formats were evaluated in a small testbed rocket thrust chamber. The rocket chamber was designed to evaluate several bipropellant combinations. Optical access to the chamber was provided through small sapphire windows. Test results from gaseous oxygen (GOx) and RP-1 propellants are presented here. Several variables were evaluated during the test program, including spark location, pulse timing, and relative pulse energy. These variables were evaluated in an effort to identify the conditions in which laser ignition of bi-propellants is feasible. Preliminary results and analysis indicate that this laser ignition approach may provide superior ignition performance relative to squib and torch igniters, while simultaneously eliminating some of the logistical issues associated with these systems. Further research focused on enhancing the system robustness, multiplexing, and window durability/cleaning and fiber optic enhancements is in progress.

  12. Radiological effluents released from nuclear rocket and ramjet engine tests at the Nevada Test Site 1959 through 1969: Fact Book

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, H.N.

    1995-06-01

    Nuclear rocket and ramjet engine tests were conducted on the Nevada Test Site (NTS) in Area 25 and Area 26, about 80 miles northwest of Las Vegas, Nevada, from July 1959 through September 1969. This document presents a brief history of the nuclear rocket engine tests, information on the off-site radiological monitoring, and descriptions of the tests.

  13. HEAT TRANSFER IN EXHAUST SYSTEM OF A COLD START ENGINE AT LOW ENVIRONMENTAL TEMPERATURE

    Directory of Open Access Journals (Sweden)

    Snežana D Petković

    2010-01-01

    Full Text Available During the engine cold start, there is a significantly increased emission of harmful engine exhaust gases, particularly at very low environmental temperatures. Therefore, reducing of emission during that period is of great importance for the reduction of entire engine emission. This study was conducted to test the activating speed of the catalyst at low environmental temperatures. The research was conducted by use of mathematical model and developed computer programme for calculation of non-stationary heat transfer in engine exhaust system. During the research, some of constructional parameters of exhaust system were adopted and optimized at environmental temperature of 22 C. The combination of design parameters giving best results at low environmental temperatures was observed. The results showed that the temperature in the environment did not have any significant influence on pre-catalyst light-off time.

  14. Reducing drag of a commuter train, using engine exhaust momentum

    Science.gov (United States)

    Ha, Dong Keun

    The objective of this thesis was to perform numerical investigations of two different methods of injecting fluid momentum into the air flow above a commuter train to reduce its drag. Based on previous aerodynamic modifications of heavy duty trucks in improving fuel efficiency, two structural modifications were designed and applied to a Metrolink Services commuter train in the Los Angeles (LA) County area to reduce its drag and subsequently improve fuel efficiency. The first modification was an L-shaped channel, added to the exhaust cooling fan above the locomotive roof to divert and align the exhaust gases in the axial direction. The second modification was adding an airfoil shaped lid over the L-shape channel, to minimize the drag of the perturbed structure, and thus reduce the overall drag. The computational fluid dynamic (CFD) software CCM+ from CD-Adapco with the ?-? turbulence model was used for the simulations. A single train set which consists of three vehicles: one locomotive, one trailer car and one cab car were used. All the vehicles were modeled based on the standard Metrolink fleet train size. The wind speed was at 90 miles per hour (mph), which is the maximum speed for the Orange County Metrolink line. Air was used as the exhaust gas in the simulation. The temperature of the exhausting air emitting out of the cooling fan on the roof was 150 F and the average fan speed was 120 mph. Results showed that with the addition of the lid, momentum injection results in reduced flow separation and pressure recovery behind the locomotive, which reduces the overall drag by at least 30%.

  15. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    Science.gov (United States)

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  16. JANNAF "Test and Evaluation Guidelines for Liquid Rocket Engines": Status and Application

    Science.gov (United States)

    Parkinson, Douglas; VanLerberghe, Wayne M.; Rahman, Shamim A.

    2017-01-01

    For many decades, the U.S. rocket propulsion industrial base has performed remarkably in developing complex liquid rocket engines that can propel critical payloads into service for the nation, as well as transport people and hardware for missions that open the frontiers of space exploration for humanity. This has been possible only at considerable expense given the lack of detailed guidance that captures the essence of successful practices and knowledge accumulated over five decades of liquid rocket engine development. In an effort to provide benchmarks and guidance for the next generation of rocket engineers, the Joint Army Navy NASA Air Force (JANNAF) Interagency Propulsion Committee published a liquid rocket engine (LRE) test and evaluation (T&E) guideline document in 2012 focusing on the development challenges and test verification considerations for liquid rocket engine systems. This document has been well received and applied by many current LRE developers as a benchmark and guidance tool, both for government-driven applications as well as for fully commercial ventures. The USAF Space and Missile Systems Center (SMC) has taken an additional near-term step and is directing activity to adapt and augment the content from the JANNAF LRE T&E guideline into a standard for potential application to future USAF requests for proposals for LRE development initiatives and launch vehicles for national security missions. A draft of this standard was already sent out for review and comment, and is intended to be formally approved and released towards the end of 2017. The acceptance and use of the LRE T&E guideline is possible through broad government and industry participation in the JANNAF liquid propulsion committee and associated panels. The sponsoring JANNAF community is expanding upon this initial baseline version and delving into further critical development aspects of liquid rocket propulsion testing at the integrated stage level as well as engine component level, in

  17. Subscale Carbon-Carbon Nozzle Extension Development and Hot Fire Testing in Support of Upper Stage Liquid Rocket Engines

    Science.gov (United States)

    Gradl, Paul; Valentine, Peter; Crisanti, Matthew; Greene, Sandy Elam

    2016-01-01

    Upper stage and in-space liquid rocket engines are optimized for performance through the use of high area ratio nozzles to fully expand combustion gases to low exit pressures increasing exhaust velocities. Due to the large size of such nozzles and the related engine performance requirements, carbon-carbon (C/C) composite nozzle extensions are being considered for use in order to reduce weight impacts. NASA and industry partner Carbon-Carbon Advanced Technologies (C-CAT) are working towards advancing the technology readiness level of large-scale, domestically-fabricated, C/C nozzle extensions. These C/C extensions have the ability to reduce the overall costs of extensions relative to heritage metallic and composite extensions and to decrease weight by 50%. Material process and coating developments have advanced over the last several years, but hot fire testing to fully evaluate C/C nozzle extensions in relevant environments has been very limited. NASA and C-CAT have designed, fabricated and hot fire tested multiple subscale nozzle extension test articles of various C/C material systems, with the goal of assessing and advancing the manufacturability of these domestically producible materials as well as characterizing their performance when subjected to the typical environments found in a variety of liquid rocket and scramjet engines. Testing at the MSFC Test Stand 115 evaluated heritage and state-of-the-art C/C materials and coatings, demonstrating the capabilities of the high temperature materials and their fabrication methods. This paper discusses the design and fabrication of the 1.2k-lbf sized carbon-carbon nozzle extensions, provides an overview of the test campaign, presents results of the hot fire testing, and discusses potential follow-on development work.

  18. Heat transfer modeling in exhaust systems of high-performance two-stroke engines

    OpenAIRE

    Lujan Martinez, José Manuel; Climent Puchades, Héctor; Olmeda González, Pablo Cesar; JIMENEZ MACEDO, VICTOR DANIEL

    2014-01-01

    Heat transfer from the hot gases to the wall in exhaust systems of high-performance two-stroke engines is underestimated using steady state with fully developed flow empirical correlations. This fact is detected when comparing measured and modeled pressure pulses in different positions in the exhaust system. This can be explained taking into account that classical expressions have been validated for fully developed flows, a situation that is far from the flow behavior in reciprocating interna...

  19. A Research on The Exhaust Emission of The Gasoline Engines in Tekirdag

    OpenAIRE

    M.R. Durgut; S. Arin; E.Kilic

    2006-01-01

    The exhaust gases as a result of combustion in internal combustion engines, sump ventilatory systemand vaporization of fuel system are the pollution sources caused by the vehicles. Preventing the pollution inits source is the main method for controlling the pollution: In this study, the exhaust emissions of 1844vehicles with gasoline were examined randomly applied to measuring station. The measured CO, CO2 HC,O2 values were discussed in their suitability to the limits determined by Turkish St...

  20. A parametric design of compact exhaust manifold junction in heavy duty diesel engine using CFD

    OpenAIRE

    Naeimi Hessamedin; Domiry Ganji Davood; Gorji Mofid; Javadirad Ghasem; Keshavarz Mojtaba

    2011-01-01

    Nowadays, computational fluid dynamics codes (CFD) are prevalently used to simulate the gas dynamics in many fluid piping systems such as steam and gas turbines, inlet and exhaust in internal combustion engines. In this paper, a CFD software is used to obtain the total energy losses in adiabatic compressible flow at compact exhaust manifold junction. A steady state onedimensional adiabatic compressible flow with friction model has been applied to subtract the straight pipe friction loss...

  1. Identification of informative features for predicting proinflammatory potentials of engine exhausts.

    Science.gov (United States)

    Wang, Chia-Chi; Lin, Ying-Chi; Lin, Yuan-Chung; Jhang, Syu-Ruei; Tung, Chun-Wei

    2017-08-18

    The immunotoxicity of engine exhausts is of high concern to human health due to the increasing prevalence of immune-related diseases. However, the evaluation of immunotoxicity of engine exhausts is currently based on expensive and time-consuming experiments. It is desirable to develop efficient methods for immunotoxicity assessment. To accelerate the development of safe alternative fuels, this study proposed a computational method for identifying informative features for predicting proinflammatory potentials of engine exhausts. A principal component regression (PCR) algorithm was applied to develop prediction models. The informative features were identified by a sequential backward feature elimination (SBFE) algorithm. A total of 19 informative chemical and biological features were successfully identified by SBFE algorithm. The informative features were utilized to develop a computational method named FS-CBM for predicting proinflammatory potentials of engine exhausts. FS-CBM model achieved a high performance with correlation coefficient values of 0.997 and 0.943 obtained from training and independent test sets, respectively. The FS-CBM model was developed for predicting proinflammatory potentials of engine exhausts with a large improvement on prediction performance compared with our previous CBM model. The proposed method could be further applied to construct models for bioactivities of mixtures.

  2. Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

    International Nuclear Information System (INIS)

    Labib, Satira; King, Jeffrey

    2015-01-01

    Graphical abstract: - Highlights: • Three NTR reactors are optimized for the single stage launch of 1–15 MT payloads. • The proposed rocket engines have specific impulses in excess of 700 s. • Reactivity and submersion criticality requirements are satisfied for each reactor. - Abstract: Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800 s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40 cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120 cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort

  3. Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

    Energy Technology Data Exchange (ETDEWEB)

    Labib, Satira, E-mail: Satira.Labib@duke-energy.com; King, Jeffrey, E-mail: kingjc@mines.edu

    2015-06-15

    Graphical abstract: - Highlights: • Three NTR reactors are optimized for the single stage launch of 1–15 MT payloads. • The proposed rocket engines have specific impulses in excess of 700 s. • Reactivity and submersion criticality requirements are satisfied for each reactor. - Abstract: Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800 s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40 cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120 cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort.

  4. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

  5. Effect of exhaust gas recirculation on diesel engine nitrogen oxide reduction operating with jojoba methyl ester

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.E. [Mechanical Power Department, Faculty of Engineering, Mattaria, Helwan University, 9 k Eltaaweniat, Nasr Road, P.O. Box 11718, Cairo (Egypt)

    2009-10-15

    Jojoba methyl ester (JME) has been used as a renewable fuel in numerous studies evaluating its potential use in diesel engines. These studies showed that this fuel is good gas oil substitute but an increase in the nitrogenous oxides emissions was observed at all operating conditions. The aim of this study mainly was to quantify the efficiency of exhaust gas recirculation (EGR) when using JME fuel in a fully instrumented, two-cylinder, naturally aspirated, four-stroke direct injection diesel engine. The tests were carried out in three sections. Firstly, the measured performance and exhaust emissions of the diesel engine operating with diesel fuel and JME at various speeds under full load are determined and compared. Secondly, tests were performed at constant speed with two loads to investigate the EGR effect on engine performance and exhaust emissions including nitrogenous oxides (NO{sub x}), carbon monoxide (CO), unburned hydrocarbons (HC) and exhaust gas temperatures. Thirdly, the effect of cooled EGR with high ratio at full load on engine performance and emissions was examined. The results showed that EGR is an effective technique for reducing NO{sub x} emissions with JME fuel especially in light-duty diesel engines. With the application of the EGR method, the CO and HC concentration in the engine-out emissions increased. For all operating conditions, a better trade-off between HC, CO and NO{sub x} emissions can be attained within a limited EGR rate of 5-15% with very little economy penalty. (author)

  6. Laser-Induced Emissions Sensor for Soot Mass in Rocket Plumes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A method is proposed to measure soot mass concentration non-intrusively from a distance in a rocket engine exhaust stream during ground tests using laser-induced...

  7. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  8. Study on performance and emission characteristics of a single cylinder diesel engine using exhaust gas recirculation

    Directory of Open Access Journals (Sweden)

    Anantha Raman Lakshmipathi

    2017-01-01

    Full Text Available Exhaust gas re-circulation is a method used in compression ignition engines to control and reduce NOx emission. These emissions are controlled by reducing the oxygen concentration inside the cylinder and thereby reducing the flame temperature of the charge mixture inside the combustion chamber. In the present investigation, experiments were performed to study the effect of exhaust gas re-circulation on performance and emission characteristics in a four stroke single cylinder, water cooled and constant speed diesel engine. The experiments were performed to study the performance and emissions for different exhaust gas re-circulation ratios of the engine. Performance parameters such as brake thermal efficiency, indicated thermal efficiency, specific fuel consumption, total fuel consumption and emission parameters such as oxides of nitrogen, unburned hydrocarbons, carbon monoxide, carbon dioxide and smoke opacity were measured. Reductions in NOx and CO2 were observed but other emissions like HC, CO, and smoke opacity were found to have increased with the usage of exhaust gas re-circulation. The 15% exhaust gas re-circulation was found optimum for the engine in the aspects of performance and emission.

  9. Lightweight Exit Cone for Liquid Rocket Engines, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Pratt and Whitney Rocketdyne (PWR) J-2X engine will power the upper stage of the Ares I and the earth departure stage (EDS) of the Ares V, which will enable...

  10. Effect of exhaust gas recirculation on some combustion characteristics of dual fuel engine

    Energy Technology Data Exchange (ETDEWEB)

    Selim, Mohamed Y.E. [United Arab Emirates Univ., Dept. of Mechanical Engineering, Al-Ain (United Arab Emirates)

    2003-03-01

    Combustion pressure rise rate and thermal efficiency data are measured and presented for a dual fuel engine running on a dual fuel of Diesel and compressed natural gas and utilizing exhaust gas recirculation (EGR). The maximum pressure rise rate during combustion is presented as a measure of combustion noise. The experimental investigation on the dual fuel engine revealed the noise generated from combustion and the thermal efficiency at different EGR ratios. A Ricardo E6 Diesel version engine is converted to run on a dual fuel of Diesel and compressed natural gas and having an exhaust gas recycling system is used throughout the work. The engine is fully computerized, and the cylinder pressure data and crank angle data are stored in a PC for offline analysis. The effects of EGR ratio, engine speeds, loads, temperature of recycled exhaust gases, intake charge pressure and engine compression ratio on combustion noise and thermal efficiency are examined for the dual fuel engine. The combustion noise and thermal efficiency of the dual fuel engine are found to be affected when EGR is used in the dual fuel engine. (Author)

  11. Study of SI engine fueled with methanol vapor and dissociation gas based on exhaust heat dissociating methanol

    International Nuclear Information System (INIS)

    Fu, Jianqin; Deng, Banglin; Liu, Jingping; Wang, Linjun; Xu, Zhengxin; Yang, Jing; Shu, Gequn

    2014-01-01

    Highlights: • The full load power decreases successively from gasoline engine, methanol vapor engine to dissociated methanol engine. • Both power and thermal efficiency of dissociated methanol engine can be improved by boosting pressure. • The conversion efficiency of recovered exhaust gas energy is largely influenced by the BMEP. • At the same BMEP, dissociated methanol engine has higher thermal efficiency than methanol vapor engine and gasoline engine. - Abstract: To improve the fuel efficiency of internal combustion (IC) engine and also achieve the goal of direct usage of methanol fuel on IC engine, an approach of exhaust heat dissociating methanol was investigated, which is a kind of method for IC engine exhaust heat recovery (EHR). A bottom cycle system is coupled with the IC engine exhaust system, which uses the exhaust heat to evaporate and dissociate methanol in its catalytic cracker. The methanol dissociation gas (including methanol vapor) is used as the fuel for IC engine. This approach was applied to both naturally aspirated (NA) engine and turbocharged engine, and the engine performance parameters were predicted by the software GT-power under various kinds of operating conditions. The improvement to IC engine performance and the conversion efficiency of recovered exhaust gas energy can be evaluated by comparing the performances of IC engine fueled with various kinds of fuels (or their compositions). Results show that, from gasoline engine, methanol vapor engine to dissociated methanol engine, the full load power decreases successively in the entire speed area due to the declining of volumetric efficiency, while it is contrary in the thermal efficiency at the same brake mean effective pressure (BMEP) level because of the improving of fuel heating value. With the increase of BMEP, the conversion efficiency of recovered exhaust gas energy is promoted. All those results indicate that the approach of exhaust heat dissociating methanol has large

  12. Investigation and design optimization of exhaust-based thermoelectric generator system for internal combustion engine

    International Nuclear Information System (INIS)

    Niu, Zhiqiang; Diao, Hai; Yu, Shuhai; Jiao, Kui; Du, Qing; Shu, Gequn

    2014-01-01

    Highlights: • A 3-D model for exhaust-based thermoelectric waste heat recovery is developed. • Various heat, mass and electric transfer characteristics are elucidated. • Channel size needs to be moderate to balance heat transfer and pressure drop. • Bafflers need to be placed at all locations near all TEG modules. • Baffler angle needs to be sufficiently large, especially for downstream locations. - Abstract: Thermoelectric generator (TEG) has attracted considerable attention for the waste heat recovery of internal combustion engine. In this study, a 3-D numerical model for engine exhaust-based thermoelectric generator (ETEG) system is developed. By considering the detailed geometry of thermoelectric generator (TEG) and exhaust channel, the various transport phenomena are investigated, and design optimization suggestions are given. It is found that the exhaust channel size needs to be moderate to balance the heat transfer to TEG modules and pressure drop along channel. Increasing the number of exhaust channels may improve the performance, however, since more space and TEG modules are needed, the system size and cost need to be considered as well. Although only placing bafflers at the channel inlet could increase the heat transfer coefficient for the whole channel, the near wall temperature downstream might decrease significantly, leading to performance degradation of the TEG modules downstream. To ensure effective utilization of hot exhaust gas, the baffler angle needs to be sufficiently large, especially for the downstream locations. Since larger baffler angles increase the pressure drop significantly, it is suggested that variable baffler angles, with the angle increasing along the flow direction, might be a middle course for balancing the heat transfer and pressure drop. A single ETEG design may not be suitable to all the engine operating conditions, and making the number of exhaust channels and baffler angle adjustable according to different engine

  13. A Framework for Modular Modeling of the Diesel Engine Exhaust Gas Cleaning System

    DEFF Research Database (Denmark)

    Åberg, Andreas; Hansen, Thomas Klint; Linde, Kasper

    2015-01-01

    Pollutants from diesel engines have a negative effect on urban air quality. Because of this and new legislation restricting the emission level, it is necessary to develop exhaust gas treatment systems for diesel engines that can reduce the amount of pollutants. A modular model capable of simulating...... model. Four different models in the automotive diesel exhaust gas cleaning system are presented briefly. Based on the presented methodology, it is discussed which changes are needed to the models to create a modular model of the whole catalytic system....

  14. Rocket Engine Health Management: Early Definition of Critical Flight Measurements

    Science.gov (United States)

    Christenson, Rick L.; Nelson, Michael A.; Butas, John P.

    2003-01-01

    The NASA led Space Launch Initiative (SLI) program has established key requirements related to safety, reliability, launch availability and operations cost to be met by the next generation of reusable launch vehicles. Key to meeting these requirements will be an integrated vehicle health management ( M) system that includes sensors, harnesses, software, memory, and processors. Such a system must be integrated across all the vehicle subsystems and meet component, subsystem, and system requirements relative to fault detection, fault isolation, and false alarm rate. The purpose of this activity is to evolve techniques for defining critical flight engine system measurements-early within the definition of an engine health management system (EHMS). Two approaches, performance-based and failure mode-based, are integrated to provide a proposed set of measurements to be collected. This integrated approach is applied to MSFC s MC-1 engine. Early identification of measurements supports early identification of candidate sensor systems whose design and impacts to the engine components must be considered in engine design.

  15. Transient Mathematical Modeling for Liquid Rocket Engine Systems: Methods, Capabilities, and Experience

    Science.gov (United States)

    Seymour, David C.; Martin, Michael A.; Nguyen, Huy H.; Greene, William D.

    2005-01-01

    The subject of mathematical modeling of the transient operation of liquid rocket engines is presented in overview form from the perspective of engineers working at the NASA Marshall Space Flight Center. The necessity of creating and utilizing accurate mathematical models as part of liquid rocket engine development process has become well established and is likely to increase in importance in the future. The issues of design considerations for transient operation, development testing, and failure scenario simulation are discussed. An overview of the derivation of the basic governing equations is presented along with a discussion of computational and numerical issues associated with the implementation of these equations in computer codes. Also, work in the field of generating usable fluid property tables is presented along with an overview of efforts to be undertaken in the future to improve the tools use for the mathematical modeling process.

  16. Fluid dynamic modeling of junctions in internal combustion engine inlet and exhaust systems

    Science.gov (United States)

    Chalet, David; Chesse, Pascal

    2010-10-01

    The modeling of inlet and exhaust systems of internal combustion engine is very important in order to evaluate the engine performance. This paper presents new pressure losses models which can be included in a one dimensional engine simulation code. In a first part, a CFD analysis is made in order to show the importance of the density in the modeling approach. Then, the CFD code is used, as a numerical test bench, for the pressure losses models development. These coefficients depend on the geometrical characteristics of the junction and an experimental validation is made with the use of a shock tube test bench. All the models are then included in the engine simulation code of the laboratory. The numerical calculation of unsteady compressible flow, in each pipe of the inlet and exhaust systems, is made and the calculated engine torque is compared with experimental measurements.

  17. Design of a 500 lbf liquid oxygen and liquid methane rocket engine for suborbital flight

    Science.gov (United States)

    Trillo, Jesus Eduardo

    Liquid methane (LCH4)is the most promising rocket fuel for our journey to Mars and other space entities. Compared to liquid hydrogen, the most common cryogenic fuel used today, methane is denser and can be stored at a more manageable temperature; leading to more affordable tanks and a lighter system. The most important advantage is it can be produced from local sources using in-situ resource utilization (ISRU) technology. This will allow the production of the fuel needed to come back to earth on the surface of Mars, or the space entity being explored, making the overall mission more cost effective by enabling larger usable mass. The major disadvantage methane has over hydrogen is it provides a lower specific impulse, or lower rocket performance. The UTEP Center for Space Exploration and Technology Research (cSETR) in partnership with the National Aeronautics and Space Administration (NASA) has been the leading research center for the advancement of Liquid Oxygen (LOX) and Liquid Methane (LCH4) propulsion technologies. Through this partnership, the CROME engine, a throattable 500 lbf LOX/LCH4 rocket engine, was designed and developed. The engine will serve as the main propulsion system for Daedalus, a suborbital demonstration vehicle being developed by the cSETR. The purpose of Daedalus mission and the engine is to fire in space under microgravity conditions to demonstrate its restartability. This thesis details the design process, decisions, and characteristics of the engine to serve as a complete design guide.

  18. Characterization of Rotating Detonation Engine Exhaust Through Nozzle Guide Vanes

    Science.gov (United States)

    2013-03-21

    ENY/13-M09 Abstract A Rotating Detonation Engine ( RDE ) has higher thermal efficiencies in comparison to its traditional gas turbine counterparts. Thus...as budgets decrease and fuel costs increase, RDEs have become a research focus for the United States Air Force. An integration assembly for attaching...the first Nozzle Guide Vane (NGV) section from a T63 gas turbine engine to a 6 inch diameter RDE was designed and built for this study. Pressure

  19. Review of fuel element development for nuclear rocket engines

    International Nuclear Information System (INIS)

    Taub, J.M.

    1975-06-01

    The Los Alamos Scientific Laboratory (LASL) entered the nuclear propulsion field in 1955 and began work on all aspects of a nuclear propulsion program involving uranium-loaded graphite fuels, hydrogen propellant, and a target exhaust temperature of approximately 2500 0 C. A very extensive uranium-loaded graphite fuel element technology evolved from the program. Selection and composition of raw materials for the extrusion mix had to be coupled with heat treatment studies to give optimum element properties. The highly enriched uranium in the element was incorporated as UO 2 , pyrocarbon-coated UC 2 , or solid solution UC . ZrC particles. An extensive development program resulted in successful NbC or ZrC coatings on elements to withstand hydrogen corrosion at elevated temperatures. Hot gas, thermal shock, thermal stress, and NDT evaluation procedures were developed to monitor progress in preparation of elements with optimum properties. Final evaluation was made in reactor tests at NRDS. Aerojet-General, Westinghouse Astronuclear Laboratory, and the Oak Ridge Y-12 Plant of Union Carbide Nuclear Company entered the program in the early 1960's, and their activities paralleled those of LASL in fuel element development. (U.S.)

  20. Study of reaction between water and exhaust gases from diesel engines used in underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Mazukhina, S.I.; Kalabin, G.V.; Romanov, V.S.

    1988-05-01

    A method of mathematical simulation, based on the principle of local equilibrium of the kinetic components, was proposed for formulating and solving problems related to the combustion of fuel and the treatment of exhaust gases from a diesel engine in underground workings. Results of a study of the effects of exhaust gas quantity and composition on the reaction between the gases and water are presented. It is shown that the kinetic model correlates well with the equilibrium model, adequately describes the process, and gives a reliable picture of the changes over a period of time. The proposed method can be used to study the gas emission with different fuel mixtures and liquid neutralizing agents with a view to reducing the toxicity of diesel-engine exhaust gases.

  1. Flow effects due to pulsation in an internal combustion engine exhaust port

    International Nuclear Information System (INIS)

    Semlitsch, Bernhard; Wang, Yue; Mihăescu, Mihai

    2014-01-01

    Highlights: • Using POD analysis to identify large coherent flow structures in a complex geometry. • Flow field alters significant for constant and pulsating boundary conditions. • The discharge coefficient of the exhaust port decreases 2% with flow pulsation. • Pulsation causes a pumping mechanism due to a phase shift of pressure and momentum. - Abstract: In an internal combustion engine, the residual energy remaining after combustion in the exhaust gasses can be partially recovered by a downstream arranged device. The exhaust port represents the passage guiding the exhaust gasses from the combustion chamber to the energy recovering device, e.g. a turbocharger. Thus, energy losses in the course of transmission shall be reduced as much as possible. However, in one-dimensional engine models used for engine design, the exhaust port is reduced to its discharge coefficient, which is commonly measured under constant inflow conditions neglecting engine-like flow pulsation. In this present study, the influence of different boundary conditions on the energy losses and flow development during the exhaust stroke are analyzed numerically regarding two cases, i.e. using simple constant and pulsating boundary conditions. The compressible flow in an exhaust port geometry of a truck engine is investigated using three-dimensional Large Eddy Simulations (LES). The results contrast the importance of applying engine-like boundary conditions in order to estimate accurately the flow induced losses and the discharge coefficient of the exhaust port. The instantaneous flow field alters significantly when pulsating boundary conditions are applied. Thus, the induced losses by the unsteady flow motion and the secondary flow motion are increased with inflow pulsations. The discharge coefficient decreased about 2% with flow pulsation. A modal flow decomposition method, i.e. Proper Orthogonal Decomposition (POD), is used to analyze the coherent structures induced with the particular

  2. Experimental investigation on the influences of exhaust gas recirculation coupling with intake tumble on gasoline engine economy and emission performance

    International Nuclear Information System (INIS)

    Fu, Jianqin; Zhu, Guohui; Zhou, Feng; Liu, Jingping; Xia, Yan; Wang, Shuqian

    2016-01-01

    Highlights: • In-cylinder residual gas fraction almost increases linearly with exhaust gas recirculation rate. • Heat transfer loss and exhaust gas energy loss decrease with exhaust gas recirculation rate. • Engine indicated thermal efficiency can be increased by 4.29% at 1600 r/min and 2.94 bar. • The effective range of exhaust gas recirculation rate can be extended by intake tumble. - Abstract: To improve the economy and emission performance of gasoline engine under part load, the approach of exhaust gas recirculation coupling with intake tumble was investigated by bench testing. Based on a naturally aspirated gasoline engine, the sweeping test of exhaust gas recirculation rate was conducted in two intake modes (with/without intake tumble), and the parameters related to engine heat-work conversion process and emission performance were measured. Through comparing and analyzing the measured data, the effects of exhaust gas recirculation coupling with intake tumble on gasoline engine economy and emission performance were revealed. The results show that pumping loss decreases gradually while in-cylinder residual gas fraction increases linearly with the exhaust gas recirculation rate increasing; the high-pressure cycle efficiency ascends with exhaust gas recirculation rate increasing due to the decrease of heat transfer loss and exhaust gas energy loss. Thus, the improvement of indicated thermal efficiency is the superposition of double benefits of low-pressure cycle and high-pressure cycle. At 1600 r/min and 2.94 bar, the indicated thermal efficiency can be increased by 4.29%. With the increase of exhaust gas recirculation rate, nitrogen oxide emissions almost fall linearly, but hydrocarbon and carbonic oxide emissions have no obvious change in the effective range of exhaust gas recirculation rate. The biggest advantage of intake tumble is that it can extend the effective range of exhaust gas recirculation rate. As a result, the potential of energy

  3. The determination of aldehydes in the exhaust gases of LPG fuelled engines

    NARCIS (Netherlands)

    Rutten, G.A.F.M.; Burtner, C.W.J.; Visser, H.; Rijks, J.A.

    1988-01-01

    The exhaust gas of a LPG fuelled engine is drawn through two bubblers in series in an ice bath, and filled with saturated 2,4-dinitrophenylhydrazine in 2M HCl. After heating the derivatives are extracted with toluene-cyclohexane and 1l samples injected on-column on a OV1 capillary column. Using an

  4. Multi-Stage Selective Catalytic Reduction of NOx in Lean-Burn Engine Exhaust

    National Research Council Canada - National Science Library

    Penetrante, B

    1997-01-01

    .... A plasma can also be used to oxidize NO to NO2. This paper compares the multi-stage catalytic scheme with the plasma-assisted catalytic scheme for reduction of NOx in lean-burn engine exhausts. The advantages of plasma oxidation over catalytic oxidation are presented.

  5. Highly selective NOx reduction for diesel engine exhaust via an electrochemical system

    DEFF Research Database (Denmark)

    Shao, Jing; Tao, Youkun; Kammer Hansen, Kent

    2016-01-01

    It is challenging to reduce the nitrogen oxides (NOx) in diesel engine exhaust due to the inhibiting effect of excess oxygen. In this study, a novel electrochemical deNOx system was developed, which eliminated the need for additional reducing materials or a sophisticated controlling system as used...

  6. An overview of exhaust emissions regulatory requirements and control technology for stationary natural gas engines

    International Nuclear Information System (INIS)

    Ballard, H.N.; Hay, S.C.; Shade, W.N. Jr.

    1992-01-01

    In this paper a practical overview of stationary natural gas engine exhaust emissions control technology and trends in emissions regulatory requirements is presented. Selective and non-selective catalytic reduction and lean burn technologies are compared. Particular emphasis is focussed on implications of the Clean Air Act of 1990. Recent emissions reduction conversion kit developments and a practical approach to continuous monitoring are discussed

  7. Occupational exposure to diesel engine exhaust and alterations in lymphocyte subsets

    NARCIS (Netherlands)

    Lan, Qing; Vermeulen, Roel; Dai, Yufei; Ren, Dianzhi; Hu, Wei; Duan, Huawei; Niu, Yong; Xu, Jun; Fu, Wei; Meliefste, Kees; Zhou, Baosen; Yang, Jufang; Ye, Meng; Jia, Xiaowei; Meng, Tao; Bin, Ping; Kim, Christopher; Bassig, Bryan A; Hosgood, H Dean; Silverman, Debra; Zheng, Yuxin; Rothman, Nathaniel

    2015-01-01

    BACKGROUND: The International Agency for Research on Cancer recently classified diesel engine exhaust (DEE) as a Group I carcinogen based largely on its association with lung cancer. However, the exposure-response relationship is still a subject of debate and the underlying mechanism by which DEE

  8. Analysis of startup strategies for a particle bed reactor nuclear rocket engine

    Science.gov (United States)

    Suzuki, D. E.

    1993-06-01

    This paper develops and analyzes engine system startup strategies for a particle bed reactor (PBR) nuclear rocket engine. The strategies are designed to maintain stable flow through the PBR fuel element while reaching the design conditions as quickly as possible. The analyses are conducted using a computer model of a representative particle bed reactor and engine system. Elements of the startup strategy considered include: the coordinated control of reactor power and coolant flow; turbine inlet temperature and flow control; and use of an external starter system. The simulation results indicate that the use of an external starter system enables the engine to reach design conditions very quickly while maintaining the flow well away from the unstable regime. If a bootstrap start is used instead, the transient does not progress as fast and approaches closer to the unstable flow regime, but allows for greater engine reusability. These results can provide important information for engine designers and mission planners.

  9. Studies of an extensively axisymmetric rocket based combined cycle (RBCC) engine powered single-stage-to-orbit (SSTO) vehicle

    Science.gov (United States)

    Foster, Richard W.; Escher, William J. D.; Robinson, John W.

    1989-01-01

    The present comparative performance study has established that rocket-based combined cycle (RBCC) propulsion systems, when incorporated by essentially axisymmetric SSTO launch vehicle configurations whose conical forebody maximizes both capture-area ratio and total capture area, are capable of furnishing payload-delivery capabilities superior to those of most multistage, all-rocket launchers. Airbreathing thrust augmentation in the rocket-ejector mode of an RBCC powerplant is noted to make a major contribution to final payload capability, by comparison to nonair-augmented rocket engine propulsion systems.

  10. CONCEPT AND MODELS FOR EVALUATION OF BLACK AND WHITE SMOKE COMPONENTS IN DIESEL ENGINE EXHAUST

    Directory of Open Access Journals (Sweden)

    Igor BLYANKINSHTEIN

    2017-09-01

    Full Text Available A method for measuring exhaust smoke opacity has been developed, which allows estimating the differentiated components forming black exhaust and those forming white smoke. The method is based on video recording and special software for processing the video recording data. The flow of the diesel exhaust gas is visualised using the digital camera, against the background of the screen, on a cut of an exhaust pipe, and with sufficient illumination of the area. The screen represents standards of whiteness and blackness. The content of the black components (soot is determined by the degree of blackening of the white standard in the frames of the video, and the content of whitish components (unburned fuel and oil, etc. is determined by the degree of whitening of black standard on the frames of the video. The paper describes the principle and the results of testing the proposed method of measuring exhaust smoke opacity. We present an algorithm for the frame-by-frame analysis of the video sequence, and static and dynamic mathematical models of exhaust opacity, measured under free-acceleration of a diesel engine.

  11. Thermoelectric generators incorporating phase-change materials for waste heat recovery from engine exhaust

    Science.gov (United States)

    Meisner, Gregory P; Yang, Jihui

    2014-02-11

    Thermoelectric devices, intended for placement in the exhaust of a hydrocarbon fuelled combustion device and particularly suited for use in the exhaust gas stream of an internal combustion engine propelling a vehicle, are described. Exhaust gas passing through the device is in thermal communication with one side of a thermoelectric module while the other side of the thermoelectric module is in thermal communication with a lower temperature environment. The heat extracted from the exhaust gasses is converted to electrical energy by the thermoelectric module. The performance of the generator is enhanced by thermally coupling the hot and cold junctions of the thermoelectric modules to phase-change materials which transform at a temperature compatible with the preferred operating temperatures of the thermoelectric modules. In a second embodiment, a plurality of thermoelectric modules, each with a preferred operating temperature and each with a uniquely-matched phase-change material may be used to compensate for the progressive lowering of the exhaust gas temperature as it traverses the length of the exhaust pipe.

  12. Investigating the ionosphere response to exhaust products of “Progress” cargo spacecraft engines on the basis of Irkutsk Incoherent Scatter Radar data

    Directory of Open Access Journals (Sweden)

    Shpynev B.G.

    2017-03-01

    Full Text Available The FSUE Central Research Institute of Machine Building (TsNIIMash, Rocket and Space Corporation “Energia”, and Institute of Solar-Terrestrial Physics of Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS jointly conducted the active space experiment “Radar-Progress” in 2007–2015. During this experiment, the Irkutsk Incoherent Scatter Radar was used to study space-time characteristics of ionospheric disturbances generated by exhaust products of Progress cargo spacecraft engines. As the basic effect during exhaust product injection we consider the formation of new centers for recombination of ambient ionospheric ions O+ on molecules of water and carbon dioxide. This produces an ionization “hole” in the region of injection. In nighttime conditions when the ma-jority of experiments were performed, this hole was filled with hydrogen ions from the plasmasphere, thus changing the ion composition in the vicinity of the hole and incoherent scatter spectra. For successful observation of the ioni-zation hole dynamics, the critical factors are the degree of filling of the antenna pattern with exhaust products and the velocity of the thermospheric neutral wind, which makes exhaust gases move from the antenna pattern. These two factors lead to poor repeatability of successful experiments. Successful experiments recorded a decrease in electron density up to 35 % in the hole that existed for 30 min. The lifetime of the region with high concentration of H+ ions can be as long as one hour.

  13. Computational Fluid Dynamic Modeling of Rocket Based Combined Cycle Engine Flowfields

    Science.gov (United States)

    Daines, Russell L.; Merkle, Charles L.

    1994-01-01

    Computational Fluid Dynamic techniques are used to study the flowfield of a fixed geometry Rocket Based Combined Cycle engine operating in rocket ejector mode. Heat addition resulting from the combustion of injected fuel causes the subsonic engine flow to choke and go supersonic in the slightly divergent combustor-mixer section. Reacting flow computations are undertaken to predict the characteristics of solutions where the heat addition is determined by the flowfield. Here, adaptive gridding is used to improve resolution in the shear layers. Results show that the sonic speed is reached in the unheated portions of the flow first, while the heated portions become supersonic later. Comparison with results from another code show reasonable agreement. The coupled solutions show that the character of the combustion-based thermal choking phenomenon can be controlled reasonably well such that there is opportunity to optimize the length and expansion ratio of the combustor-mixer.

  14. HPLC analysis of aldehydes in automobile exhaust gas: Comparison of exhaust odor and irritation in different types of gasoline and diesel engines

    International Nuclear Information System (INIS)

    Roy, Murari Mohon

    2008-01-01

    This study investigated high performance liquid chromatography (HPLC) to identify and measure aldehydes from automobile exhaust gas. Four aldehydes: formaldehyde (HCHO), acetaldehyde (CH 3 CHO), acrolein (H 2 C=CHCHO) and propionaldehyde (CH 3 CH 2 CHO) and one ketone, acetone (CH 3 ) 2 CO are separated. The other higher aldehydes in exhaust gas are very small and cannot be separated. A new method of gas sampling, hereafter called bag sampling in HPLC is introduced instead of the trapping gas sampling method. The superiority of the bag sampling method is its transient gas checking capability. In the second part of this study, HPLC results are applied to compare exhaust odor and irritation of exhaust gases in different types of gasoline and diesel engines. Exhaust odor, irritation and aldehydes are found worst in direct injection (DI) diesel engines and best in some good multi-point injection (MPI) gasoline and direct injection gasoline (DIG) engines. Indirect injection (IDI) diesel engines showed odor, irritation and aldehydes in between the levels of MPI gasoline, DIG and DI diesel engines

  15. Occupational exposures to engine exhausts and other PAHs and breast cancer risk: A population-based case-control study.

    Science.gov (United States)

    Rai, Rajni; Glass, Deborah C; Heyworth, Jane S; Saunders, Christobel; Fritschi, Lin

    2016-06-01

    Some previous studies have suggested that exposure to engine exhausts may increase risk of breast cancer. In a population-based case-control study of breast cancer in Western Australia we assessed occupational exposure to engine exhausts using questionnaires and telephone interviews. Odds Ratios (OR) and 95% Confidence Intervals (CI) were calculated using logistic regression. We found no association between risk of breast cancer and occupational exposure to diesel exhaust (OR 1.07, 95%CI: 0.81-1.41), gasoline exhaust (OR 0.98, 95%CI: 0.74-1.28), or other exhausts (OR 1.08, 95%CI: 0.29-4.08). There were also no significant dose- or duration-response relationships. This study did not find evidence supporting the association between occupational exposures to engine exhausts and breast cancer risk. Am. J. Ind. Med. 59:437-444, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Temperature monitoring of vehicle engine exhaust gases under vibration condition using optical fibre temperature sensor systems

    International Nuclear Information System (INIS)

    Zhao, W Z; Suna, T; Grattana, K T V; Shen, Y H; Wei, C L; Al-Shamma'a, A I

    2006-01-01

    Two optical approaches, comprising and contracting both the fluorescence decay lifetime and the fibre Bragg grating (FBG) methods, were developed and evaluated for temperature monitoring of exhaust gases for use on a vehicle engine. The FBGs used in the system were written into specially designed Bi-Ge co-doped photosensitive fibres, to enable them to sustain high temperatures to over 800 0 C, which is far beyond that of FBGs written into most commercial photosensitive fibres. The sensors were subjected to a range of vibration tests, as a part of an optical exhaust monitoring network under development, and results from the test carried out are reported

  17. Exhaust gas heat recovery through secondary expansion cylinder and water injection in an internal combustion engine

    Directory of Open Access Journals (Sweden)

    Nassiri Toosi Ali

    2017-01-01

    Full Text Available To enhance thermal efficiency and increase performance of an internal combustion engine, a novel concept of coupling a conventional engine with a secondary 4-stroke cylinder and direct water injection process is proposed. The burned gases after working in a traditional 4-stroke combustion cylinder are transferred to a secondary cylinder and expanded even more. After re-compression of the exhaust gases, pre-heated water is injected at top dead center. The evaporation of injected water not only recovers heat from exhaust gases, but also increases the mass of working gas inside the cylinder, therefore improves the overall thermal efficiency. A 0-D/1-D model is used to numerically simulate the idea. The simulations outputs showed that the bottoming cycle will be more efficient at higher engines speeds, specifically in a supercharged/turbocharged engine, which have higher exhaust gas pressure that can reproduce more positive work. In the modeled supercharged engine, results showed that brake thermal efficiency can be improved by about 17%, and brake power by about 17.4%.

  18. Impact of the injection dose of exhaust gases, on work parameters of combustion engine

    Science.gov (United States)

    Marek, W.; Śliwiński, K.

    2016-09-01

    This article is another one from the series in which were presented research results indicated the possible areas of application of the pneumatic injection using hot combustion gases proposed by Professor Jarnuszkiewicz. This publication present the results of the control system of exhaust gas recirculation. The main aim of this research was to determine the effect of exhaust gas recirculation to the operating parameters of the internal combustion engine on the basis of laboratory measurements. All measurements were performed at a constant engine speed. These conditions correspond to the operation of the motor operating an electrical generator. The study was conducted on the four-stroke two-cylinder engine with spark ignition. The study were specifically tested on the air injection system and therefore the selection of the rotational speed was not bound, as in conventional versions of operating parameters of the electrical machine. During the measurement there were applied criterion which used power control corresponding to the requirements of load power, at minimal values of engine speed. Recirculation value determined by the following recurrent position control valve of the injection doses inflator gas for pneumatic injection system. They were studied and recorded, the impact of dose of gases recirculation to the operating and ecological engine parameters such as power, torque, specific fuel consumption, efficiency, air fuel ratio, exhaust gas temperature and nitrogen oxides and hydrocarbons.

  19. Monitoring of diesel engine combustions based on the acoustic source characterisation of the exhaust system

    Science.gov (United States)

    Jiang, J.; Gu, F.; Gennish, R.; Moore, D. J.; Harris, G.; Ball, A. D.

    2008-08-01

    Acoustic methods are among the most useful techniques for monitoring the condition of machines. However, the influence of background noise is a major issue in implementing this method. This paper introduces an effective monitoring approach to diesel engine combustion based on acoustic one-port source theory and exhaust acoustic measurements. It has been found that the strength, in terms of pressure, of the engine acoustic source is able to provide a more accurate representation of the engine combustion because it is obtained by minimising the reflection effects in the exhaust system. A multi-load acoustic method was then developed to determine the pressure signal when a four-cylinder diesel engine was tested with faults in the fuel injector and exhaust valve. From the experimental results, it is shown that a two-load acoustic method is sufficient to permit the detection and diagnosis of abnormalities in the pressure signal, caused by the faults. This then provides a novel and yet reliable method to achieve condition monitoring of diesel engines even if they operate in high noise environments such as standby power stations and vessel chambers.

  20. Paraffin-based hybrid rocket engines applications: A review and a market perspective

    Science.gov (United States)

    Mazzetti, Alessandro; Merotto, Laura; Pinarello, Giordano

    2016-09-01

    Hybrid propulsion technology for aerospace applications has received growing attention in recent years due to its important advantages over competitive solutions. Hybrid rocket engines have a great potential for several aeronautics and aerospace applications because of their safety, reliability, low cost and high performance. As a consequence, this propulsion technology is feasible for a number of innovative missions, including space tourism. On the other hand, hybrid rocket propulsion's main drawback, i.e. the difficulty in reaching high regression rate values using standard fuels, has so far limited the maturity level of this technology. The complex physico-chemical processes involved in hybrid rocket engines combustion are of major importance for engine performance prediction and control. Therefore, further investigation is ongoing in order to achieve a more complete understanding of such phenomena. It is well known that one of the most promising solutions for overcoming hybrid rocket engines performance limits is the use of liquefying fuels. Such fuels can lead to notably increased solid fuel regression rate due to the so-called "entrainment phenomenon". Among liquefying fuels, paraffin-based formulations have great potentials as solid fuels due to their low cost, availability (as they can be derived from industrial waste), low environmental impact and high performance. Despite the vast amount of literature available on this subject, a precise focus on market potential of paraffins for hybrid propulsion aerospace applications is lacking. In this work a review of hybrid rocket engines state of the art was performed, together with a detailed analysis of the possible applications of such a technology. A market study was carried out in order to define the near-future foreseeable development needs for hybrid technology application to the aforementioned missions. Paraffin-based fuels are taken into account as the most promising segment for market development

  1. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    Directory of Open Access Journals (Sweden)

    Juan Miguel Mantilla

    2009-01-01

    Full Text Available Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in real engines’ exhaust pipes. This work also considers how the simulation must be made, based on the previous exploration. The results (presented as e- quations in this first paper show the great influence exerted by pressure wave movement on flow through the engine and there- fore on its final performance.

  2. A Mathematical Model for the Exhaust Gas Temperature Profile of a Diesel Engine

    Science.gov (United States)

    Brito, C. H. G.; Maia, C. B.; Sodré, J. R.

    2015-09-01

    This work presents a heat transfer model for the exhaust gas of a diesel power generator to determine the gas temperature profile in the exhaust pipe. The numerical methodology to solve the mathematical model was developed using a finite difference method approach for energy equation resolution and determination of temperature profiles considering turbulent fluid flow and variable fluid properties. The simulation was carried out for engine operation under loads from 0 kW to 40 kW. The model was compared with results obtained using the multidimensional Ansys CFX software, which was applied to solve the governor equations of turbulent fluid flow. The results for the temperature profiles in the exhaust pipe show a good proximity between the mathematical model developed and the multidimensional software.

  3. The Australian Work Exposures Study: prevalence of occupational exposure to diesel engine exhaust.

    Science.gov (United States)

    Peters, Susan; Carey, Renee N; Driscoll, Timothy R; Glass, Deborah C; Benke, Geza; Reid, Alison; Fritschi, Lin

    2015-06-01

    Diesel engines are widely used in occupational settings. Diesel exhaust has been classified as a lung carcinogen, but data on number of workers exposed to different levels of diesel exhaust are not available in Australia. The aim of this study was to estimate the current prevalence of exposure to diesel engine exhaust in Australian workplaces. A cross-sectional survey of Australian males and females (18-65 years old) in current paid employment was undertaken. Information about the respondents' current job and various demographic factors was collected in a telephone interview using the web-based tool OccIDEAS. Semi-quantitative occupational exposure levels to diesel exhaust were assigned using programmed decision rules and numbers of workers exposed in Australia in 2011 were estimated. We defined substantial exposure as exposed at a medium or high level, for at least 5h per week. Substantial occupational exposure to diesel exhaust was experienced by 13.4% of the respondents in their current job. Exposure prevalence varied across states, ranging from 6.4% in the Australian Capital Territory to 17.0% in Western Australia. Exposures occurred mainly in the agricultural, mining, transport and construction industries, and among mechanics. Men (20.4%) were more often exposed than women (4.7%). Extrapolation to the total working population indicated that 13.8% (95% confidence interval 10.0-20.4) of the 2011 Australian workforce were estimated to be substantially exposed to diesel exhaust, and 1.8% of the workers were estimated to experience high levels of exposures in their current job. About 1.2 million Australian workers were estimated to have been exposed to diesel exhaust in their workplace in 2011. This is the first study to describe the prevalence of occupational diesel exhaust exposure in Australia and will enable estimation of the number of lung cancers attributable to diesel exhaust exposure in the workplace. © The Author 2015. Published by Oxford University Press

  4. EFFECTS OF ETHANOL BLENDED DIESEL FUEL ON EXHAUST EMISSIONS FROM A DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    Özer CAN

    2005-02-01

    Full Text Available Diesel engine emissions can be improved by adding organic oxygenated compounds to the No. 2 diesel fuel. In this study, effects of 10 % and 15 % (in volume ethanol addition to Diesel No. 2 on exhaust emissions from an indirect injection turbocharged diesel engine running at different engine speeds and loads were investigated. Experimental results showed that the ethanol addition reduced CO, soot and SO2 emissions, although it caused some increase in NOx emission and some power reductions due to lower heating value of ethanol. Improvements on emissions were more significant at full load rather than at partial loads.

  5. Review of organic Rankine cycles for internal combustion engine exhaust waste heat recovery

    International Nuclear Information System (INIS)

    Sprouse, Charles; Depcik, Christopher

    2013-01-01

    Escalating fuel prices and future carbon dioxide emission limits are creating a renewed interest in methods to increase the thermal efficiency of engines beyond the limit of in-cylinder techniques. One promising mechanism that accomplishes both objectives is the conversion of engine waste heat to a more useful form of energy, either mechanical or electrical. This paper reviews the history of internal combustion engine exhaust waste heat recovery focusing on Organic Rankine Cycles since this thermodynamic cycle works well with the medium-grade energy of the exhaust. Selection of the cycle expander and working fluid are the primary focus of the review, since they are regarded as having the largest impact on system performance. Results demonstrate a potential fuel economy improvement around 10% with modern refrigerants and advancements in expander technology. -- Highlights: ► This review article focuses on engine exhaust waste heat recovery works. ► The organic Rankine cycle is superior for low to medium exergy heat sources. ► Working fluid and expander selection strongly influence efficiency. ► Several authors demonstrate viable systems for vehicle installation

  6. An Object-Oriented Graphical User Interface for a Reusable Rocket Engine Intelligent Control System

    Science.gov (United States)

    Litt, Jonathan S.; Musgrave, Jeffrey L.; Guo, Ten-Huei; Paxson, Daniel E.; Wong, Edmond; Saus, Joseph R.; Merrill, Walter C.

    1994-01-01

    An intelligent control system for reusable rocket engines under development at NASA Lewis Research Center requires a graphical user interface to allow observation of the closed-loop system in operation. The simulation testbed consists of a real-time engine simulation computer, a controls computer, and several auxiliary computers for diagnostics and coordination. The system is set up so that the simulation computer could be replaced by the real engine and the change would be transparent to the control system. Because of the hard real-time requirement of the control computer, putting a graphical user interface on it was not an option. Thus, a separate computer used strictly for the graphical user interface was warranted. An object-oriented LISP-based graphical user interface has been developed on a Texas Instruments Explorer 2+ to indicate the condition of the engine to the observer through plots, animation, interactive graphics, and text.

  7. A unique nuclear thermal rocket engine using a particle bed reactor

    Science.gov (United States)

    Culver, Donald W.; Dahl, Wayne B.; McIlwain, Melvin C.

    1992-01-01

    Aerojet Propulsion Division (APD) studied 75-klb thrust Nuclear Thermal Rocket Engines (NTRE) with particle bed reactors (PBR) for application to NASA's manned Mars mission and prepared a conceptual design description of a unique engine that best satisfied mission-defined propulsion requirements and customer criteria. This paper describes the selection of a sprint-type Mars transfer mission and its impact on propulsion system design and operation. It shows how our NTRE concept was developed from this information. The resulting, unusual engine design is short, lightweight, and capable of high specific impulse operation, all factors that decrease Earth to orbit launch costs. Many unusual features of the NTRE are discussed, including nozzle area ratio variation and nozzle closure for closed loop after cooling. Mission performance calculations reveal that other well known engine options do not support this mission.

  8. Brayton cycle for internal combustion engine exhaust gas waste heat recovery

    Directory of Open Access Journals (Sweden)

    J Galindo

    2015-06-01

    Full Text Available An average passenger car engine effectively uses about one-third of the fuel combustion energy, while the two-thirds are wasted through exhaust gases and engine cooling. It is of great interest to automotive industry to recover some of this wasted energy, thus increasing the engine efficiency and lowering fuel consumption and contamination. Waste heat recovery for internal combustion engine exhaust gases using Brayton cycle machine was investigated. The principle problems of application of such a system in a passenger car were considered: compressor and expander machine selection, machine size for packaging under the hood, efficiency of the cycle, and improvement of engine efficiency. Important parameters of machines design have been determined and analyzed. An average 2-L turbocharged gasoline engine’s New European Driving Cycle points were taken as inlet points for waste heat recovery system. It is theoretically estimated that the recuperated power of 1515 W can be achieved along with 5.7% improvement in engine efficiency, at the point where engine power is 26550 W.

  9. Effects of water-emulsified fuel on a diesel engine generator's thermal efficiency and exhaust.

    Science.gov (United States)

    Syu, Jin-Yuan; Chang, Yuan-Yi; Tseng, Chao-Heng; Yan, Yeou-Lih; Chang, Yu-Min; Chen, Chih-Chieh; Lin, Wen-Yinn

    2014-08-01

    Water-emulsified diesel has proven itself as a technically sufficient improvement fuel to improve diesel engine fuel combustion emissions and engine performance. However, it has seldom been used in light-duty diesel engines. Therefore, this paper focuses on an investigation into the thermal efficiency and pollution emission analysis of a light-duty diesel engine generator fueled with different water content emulsified diesel fuels (WD, including WD-0, WD-5, WD-10, and WD-15). In this study, nitric oxide, carbon monoxide, hydrocarbons, and carbon dioxide were analyzed by a vehicle emission gas analyzer and the particle size and number concentration were measured by an electrical low-pressure impactor. In addition, engine loading and fuel consumption were also measured to calculate the thermal efficiency. Measurement results suggested that water-emulsified diesel was useful to improve the thermal efficiency and the exhaust emission of a diesel engine. Obviously, the thermal efficiency was increased about 1.2 to 19.9%. In addition, water-emulsified diesel leads to a significant reduction of nitric oxide emission (less by about 18.3 to 45.4%). However the particle number concentration emission might be increased if the loading of the generator becomes lower than or equal to 1800 W. In addition, exhaust particle size distributions were shifted toward larger particles at high loading. The consequence of this research proposed that the water-emulsified diesel was useful to improve the engine performance and some of exhaust emissions, especially the NO emission reduction. Implications: The accumulated test results provide a good basis to resolve the corresponding pollutants emitted from a light-duty diesel engine generator. By measuring and analyzing transforms of exhaust pollutant from this engine generator, the effects of water-emulsified diesel fuel and loading on emission characteristics might be more clear. Understanding reduction of pollutant emissions during the use

  10. Design of a 2000 lbf LOX/LCH4 Throttleable Rocket Engine for a Vertical Lander

    Science.gov (United States)

    Lopez, Israel

    Liquid oxygen (LOX) and liquid methane (LCH4) has been recognized as an attractive rocket propellant combination because of its in-situ resource utilization (ISRU) capabilities, namely in Mars. ISRU would allow launch vehicles to carry greater payloads and promote missions to Mars. This has led to an increasing interest to develop spacecraft technologies that employ this propellant combination. The UTEP Center for Space Exploration and Technology Research (cSETR) has focused part of its research efforts to developing LOX/LCH4 systems. One of those projects includes the development of a vertical takeoff and landing vehicle called JANUS. This vehicle will employ a LOX/LCH 4 propulsion system. The main propulsion engine is called CROME-X and is currently being developed as part of this project. This rocket engine will employ LOX/LCH4 propellants and is intended to operate from 2000-500 lbf thrust range. This thesis describes the design and development of CROME-X. Specifically, it describes the design process for the main engine components, the design criteria for each, and plans for future engine development.

  11. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Directory of Open Access Journals (Sweden)

    Qiang WEI

    2017-08-01

    Full Text Available To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray, the conventional uncoupled spray model for impinging injectors is extended by considering the coupling of the jet impingement process and the ambient gas field. The new coupled model consists of the plain-orifice sub-model, the jet-jet impingement sub-model and the droplet collision sub-model. The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions. The overall model is benchmarked under various impingement angles, jet momentum and off-center ratios. Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics, such as the mass flux and mixture ratio distributions in quiescent air. Besides, impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions. First, a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile. The minimum average droplet diameter is achieved when the orifices work in cavitation state, and is about 30% smaller than the steady single phase state. Second, the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°. The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

  12. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Institute of Scientific and Technical Information of China (English)

    Qiang WEI; Guozhu LIANG

    2017-01-01

    To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray,the conventional uncoupled spray model for impinging injectors is extended by considering the couplingof the jet impingement process and the ambient gas field.The new coupled model consists of the plain-orifice sub-model,the jet-jet impingement sub-model and the droplet collision sub-model.The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions.The overall model is benchmarked under various impingement angles,jet momentum and offcenter ratios.Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics,such as the mass flux and mixture ratio distributions in quiescent air.Besides,impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions.First,a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile.The minimum average droplet diameter is achieved when the orifices work in cavitation state,and is about 30% smaller than the steady single phase state.Second,the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°.The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

  13. Advanced engine management of individual cylinders for control of exhaust species

    Science.gov (United States)

    Graves, Ronald L [Knoxville, TN; West, Brian H [Knoxville, TN; Huff, Shean P [Knoxville, TN; Parks, II, James E

    2008-12-30

    A method and system controls engine-out exhaust species of a combustion engine having a plurality of cylinders. The method typically includes various combinations of steps such as controlling combustion parameters in individual cylinders, grouping the individual cylinders into a lean set and a rich set of one or more cylinders, combusting the lean set in a lean combustion parameter condition having a lean air:fuel equivalence ratio, combusting the rich set in a rich combustion parameter condition having a rich air:fuel equivalence ratio, and adjusting the lean set and the rich set of one or more cylinders to generate net-lean combustion. The exhaust species may have elevated concentrations of hydrogen and oxygen.

  14. Fate of SO(sub 2) During Plasma Treatment of Diesel Engine Exhaust

    International Nuclear Information System (INIS)

    Brusasco, R.M.; Merritt, B.T.; Vogtlin, G.E.

    1999-01-01

    Several catalytic aftertreatment technologies rely on the conversion of NO to NO(sub 2) to achieve efficient reduction of NO(sub x) and particulates in diesel engine exhaust. These technologies require low sulfur fuel because the catalyst component that is active in converting NO to NO(sub 2) is also active in converting SO(sub 2) to SO(sub 3). A non-thermal plasma can be used for the selective partial oxidation of NO to NO(sub 2) in the gas-phase under diesel engine exhaust conditions. This paper discusses how a non-thermal plasma can efficiently oxidize NO to NO(sub 2) without oxidizing SO(sub 2) to SO(sub 3). It is shown that the presence of hydrocarbons in the plasma is essential for enhancing the selective partial oxidation of NO and suppressing the oxidation of SO(sub 2)

  15. DETERMINATION OF CO2 MASSES IN THE EXHAUST GASES OF THE MARINE DIESEL ENGINES

    Directory of Open Access Journals (Sweden)

    Doru COSOFRET

    2016-05-01

    Full Text Available Currently, reducing CO2 emissions that contribute to the greenhouse effect is currently under attention of the relevant international bodies. In the field of maritime transport, in 2011 International Maritime Organization (IMO has taken steps to reduce emissions of CO2 from the exhaust gases of marine diesel engines on ships, by imposing their energy efficiency standards. In this regard, we conducted a laboratory study on a 4-stroke diesel engine naturally aspirated by using to power it diesel and different blends of biodiesel with diesel fuel. The purpose of the study was to determine the formulas for calculating the mass flow rates of CO2 from exhaust gases’ concentrations experimentally determined. Determining the mass flow of CO2 is necessary to calculate the energy efficiency coefficient of the ship to assess the energy efficiency of the board of the limits imposed by the IMO.

  16. Session 4: On-board exhaust gas reforming for improved performance of natural gas HCCI engines

    Energy Technology Data Exchange (ETDEWEB)

    Amieiro, A.; Golunski, S.; James, D. [Johnson Matthey Technology Centre, Sonning Common, Reading (United Kingdom); Miroslaw, Wyszynski; Athanasios, Megaritis; Peucheret, S. [Birmingham Univ., School of Engineering, Future Power Systems Research Group (United Kingdom); Hongming, Xu [Jaguar Cars Ltd, W/2/021 Engineering Centre, Whitley, Coventry (United Kingdom)

    2004-07-01

    Although natural gas (NG) is a non-renewable energy source, it is still a very attractive alternative fuel for transportation - it is inexpensive, abundant, and easier to refine than petroleum. Unfortunately the minimum spark energy required for NG ignition is higher than for liquid fuels, and engine performance is reduced since the higher volume of NG limits the air breathing capacity of the cylinders. On the other hand, the flammability range of NG is wider than for other hydrocarbons, so the engine can operate under leaner conditions. Environmentally, the use of NG is particularly attractive since it has a low flame temperature (resulting in reduced NO{sub x} emissions) and a low carbon content compared to diesel or gasoline (resulting in less CO, CO{sub 2} and particulate). In addition, NG is easily made sulphur-free, and has a high octane rating (RON = 110-130) which makes it suitable for high compression engine applications. Exhaust gas recirculation (EGR) into an engine is known to reduce both flame temperature and speed, and therefore produce lower NO{sub x} emissions. In general, a given volume of exhaust gas has a greater effect on flame speed and NO{sub x} emissions than the same quantity of excess air, although there is a limit to the amount of exhaust gas recirculation that can be used without inhibiting combustion. However, hydrogen addition to exhaust gas recirculation has been proved to reduce emissions while increasing flame speed, so improving both the emissions and the thermal efficiency of the engine. On-board reforming of some of the fuel, by reaction with exhaust gas during EGR, is a novel way of adding hydrogen to an engine. We have carried out reforming tests on mixtures of natural gas and exhaust gas at relatively low temperatures (400-600 C), to mimic the low availability of external heat within the integrated system. The reforming catalyst is a nickel-free formulation, containing precious metals promoted by metal oxides. The roles of

  17. An Experimental Investigation of Ethanol-Diesel Blends on Performance and Exhaust Emissions of Diesel Engines

    Directory of Open Access Journals (Sweden)

    Tarkan Sandalcı

    2014-08-01

    Full Text Available Ethanol is a promising alternative fuel, due to its renewable biobased origin. Also, it has lower carbon content than diesel fuel and it is oxygenated. For this reason, ethanol is providing remarkable potential to reduce particulate emulsions in compression-ignition engines. In this study, performance of ethanol-diesel blends has been investigated experimentally. Tested fuels were mineral diesel fuel (E0D100, 15% (v/v ethanol/diesel fuel blend (E15D85, and 30% (v/v ethanol/diesel fuel blend (E30D70. Firstly, the solubility of ethanol and diesel was experienced. Engine tests were carried out to reveal the performance and emissions of the engine fuelled with the blends. Full load operating conditions at various engine speeds were investigated. Engine brake torque, brake power, brake specific fuel consumption, brake thermal efficiency, exhaust gas temperature, and finally exhaust emissions were measured. Performance of the tested engine decreased substantially while improvement on smoke and gaseous emissions makes ethanol blend favorable.

  18. Experimental investigation on performance and exhaust emissions of castor oil biodiesel from a diesel engine.

    Science.gov (United States)

    Shojaeefard, M H; Etgahni, M M; Meisami, F; Barari, A

    2013-01-01

    Biodiesel, produced from plant and animal oils, is an important alternative to fossil fuels because, apart from dwindling supply, the latter are a major source of air pollution. In this investigation, effects of castor oil biodiesel blends have been examined on diesel engine performance and emissions. After producing castor methyl ester by the transesterification method and measuring its characteristics, the experiments were performed on a four cylinder, turbocharged, direct injection, diesel engine. Engine performance (power, torque, brake specific fuel consumption and thermal efficiency) and exhaust emissions were analysed at various engine speeds. All the tests were done under 75% full load. Furthermore, the volumetric blending ratios of biodiesel with conventional diesel fuel were set at 5, 10, 15, 20 and 30%. The results indicate that lower blends of biodiesel provide acceptable engine performance and even improve it. Meanwhile, exhaust emissions are much decreased. Finally, a 15% blend of castor oil-biodiesel was picked as the optimized blend of biodiesel-diesel. It was found that lower blends of castor biodiesel are an acceptable fuel alternative for the engine.

  19. Modified pressure loss model for T-junctions of engine exhaust manifold

    Science.gov (United States)

    Wang, Wenhui; Lu, Xiaolu; Cui, Yi; Deng, Kangyao

    2014-11-01

    The T-junction model of engine exhaust manifolds significantly influences the simulation precision of the pressure wave and mass flow rate in the intake and exhaust manifolds of diesel engines. Current studies have focused on constant pressure models, constant static pressure models and pressure loss models. However, low model precision is a common disadvantage when simulating engine exhaust manifolds, particularly for turbocharged systems. To study the performance of junction flow, a cold wind tunnel experiment with high velocities at the junction of a diesel exhaust manifold is performed, and the variation in the pressure loss in the T-junction under different flow conditions is obtained. Despite the trend of the calculated total pressure loss coefficient, which is obtained by using the original pressure loss model and is the same as that obtained from the experimental results, large differences exist between the calculated and experimental values. Furthermore, the deviation becomes larger as the flow velocity increases. By improving the Vazsonyi formula considering the flow velocity and introducing the distribution function, a modified pressure loss model is established, which is suitable for a higher velocity range. Then, the new model is adopted to solve one-dimensional, unsteady flow in a D6114 turbocharged diesel engine. The calculated values are compared with the measured data, and the result shows that the simulation accuracy of the pressure wave before the turbine is improved by 4.3% with the modified pressure loss model because gas compressibility is considered when the flow velocities are high. The research results provide valuable information for further junction flow research, particularly the correction of the boundary condition in one-dimensional simulation models.

  20. Modelling for Control of Exhaust Gas Recirculation on Large Diesel Engines

    DEFF Research Database (Denmark)

    Hansen, Jakob Mahler; Zander, Claes-Göran; Pedersen, Nicolai

    2013-01-01

    Exhaust Gas Recirculation (EGR) reduces NOx emissions by reducing O2 concentration for the combustion and is a preferred way to obtain emission regulations that will take effect from 2016. If not properly controlled, reduction of O2 has adverse side eects and proper control requires proper dynami...... principles followed by parameter identication and compares the results of these approaches. The paper performs a validation against experimental data from a test engine and presents a linearised model for EGR control design....

  1. The effect of oil additives on exhaust emission of internal combustion engines

    International Nuclear Information System (INIS)

    Dimitrovski, M.B.; Kuzmanovski, K.A.

    1999-01-01

    An attempt was conducted to acquire data on connection between motor oil and motor oil additives and exhaust emission of internal combustion engine. The consulted literature did not contain enough data, so experiments were conducted. The results of the experiments are presented on diagrams that have been processed in the computer program EXCEL. Conclusions that were made out of that work show the need of expanding research on the subject. (Author)

  2. Multi-stage selective catalytic reduction of NOx in lean burn engine exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Penetrante, B.M.; Hsaio, M.C.; Merritt, B.T.; Vogtlin, G.E. [Lawrence Livermore National Lab., CA (United States)

    1997-12-31

    Many studies suggest that the conversion of NO to NO{sub 2} is an important intermediate step in the selective catalytic reduction (SCR) of NO{sub x} to N{sub 2}. Some effort has been devoted to separating the oxidative and reductive functions of the catalyst in a multi-stage system. This method works fine for systems that require hydrocarbon addition. The hydrocarbon has to be injected between the NO oxidation catalyst and the NO{sub 2} reduction catalyst; otherwise, the first-stage oxidation catalyst will also oxidize the hydrocarbon and decrease its effectiveness as a reductant. The multi-stage catalytic scheme is appropriate for diesel engine exhausts since they contain insufficient hydrocarbons for SCR, and the hydrocarbons can be added at the desired location. For lean-burn gasoline engine exhausts, the hydrocarbons already present in the exhausts will make it necessary to find an oxidation catalyst that can oxidize NO to NO{sub 2} but not oxidize the hydrocarbon. A plasma can also be used to oxidize NO to NO{sub 2}. Plasma oxidation has several advantages over catalytic oxidation. Plasma-assisted catalysis can work well for both diesel engine and lean-burn gasoline engine exhausts. This is because the plasma can oxidize NO in the presence of hydrocarbons without degrading the effectiveness of the hydrocarbon as a reductant for SCR. In the plasma, the hydrocarbon enhances the oxidation of NO, minimizes the electrical energy requirement, and prevents the oxidation of SO{sub 2}. This paper discusses the use of multi-stage systems for selective catalytic reduction of NO{sub x}. The multi-stage catalytic scheme is compared to the plasma-assisted catalytic scheme.

  3. Prediction of emissions and exhaust temperature for direct injection diesel engine with emulsified fuel using ANN

    OpenAIRE

    KÖKKÜLÜNK, Görkem; AKDOĞAN, Erhan; AYHAN, Vezir

    2014-01-01

    Exhaust gases have many effects on human beings and the environment. Therefore, they must be kept under control. The International Convention for the Prevention of Pollution from Ships (MARPOL), which is concerned with the prevention of marine pollution, limits the emissions according to the regulations. In Emission Control Area (ECA) regions, which are determined by MARPOL as ECAs, the emission rates should be controlled. Direct injection (DI) diesel engines are commonly used as a prop...

  4. A source-independent empirical correction procedure for the fast mobility and engine exhaust particle sizers

    Science.gov (United States)

    Zimmerman, Naomi; Jeong, Cheol-Heon; Wang, Jonathan M.; Ramos, Manuel; Wallace, James S.; Evans, Greg J.

    2015-01-01

    The TSI Fast Mobility Particle Sizer (FMPS) and Engine Exhaust Particle Sizer (EEPS) provide size distributions for 6-560 nm particles with a time resolution suitable for characterizing transient particle sources; however, the accuracy of these instruments can be source dependent, due to influences of particle morphology. The aim of this study was to develop a source-independent correction protocol for the FMPS and EEPS. The correction protocol consists of: (1) broadening the >80 nm size range of the distribution to account for under-sizing by the FMPS and EEPS; (2) applying an existing correction protocol in the 8-93 nm size range; and (3) dividing each size bin by the ratio of total concentration measured by the FMPS or EEPS and a water-based Condensation Particle Counter (CPC) as a surrogate scaling factor to account for particle morphology. Efficacy of the correction protocol was assessed for three sources: urban ambient air, diluted gasoline direct injection engine exhaust, and diluted diesel engine exhaust. Linear regression against a reference instrument, the Scanning Mobility Particle Sizer (SMPS), before and after applying the correction protocol demonstrated that the correction ensured agreement within 20%.

  5. Flow effects due to valve and piston motion in an internal combustion engine exhaust port

    International Nuclear Information System (INIS)

    Semlitsch, Bernhard; Wang, Yue; Mihăescu, Mihai

    2015-01-01

    Highlights: • Flow regime identification depending on the valve lift during the exhaust stroke. • Analysis of the valve motion effect onto the flow development in the exhaust port. • Physical interpretation of commonly used discharge and flow coefficient formulations. • Illustration of flow effects in junction regions with pulsatile flow. - Abstract: Performance optimization regarding e.g. exhaust valve strategies in an internal combustion engine is often performed based on one-dimensional simulation investigation. Commonly, a discharge coefficient is used to describe the flow behavior in complex geometries, such as the exhaust port. This discharge coefficient for an exhaust port is obtained by laboratory experiments at fixed valve lifts, room temperatures, and low total pressure drops. The present study investigates the consequences of the valve and piston motion onto the energy losses and the discharge coefficient. Therefore, Large Eddy Simulations are performed in a realistic internal combustion geometry using three different modeling strategies, i.e. fixed valve lift and fixed piston, moving piston and fixed valve lift, and moving piston and moving valve, to estimate the energy losses. The differences in the flow field development with the different modeling approaches is delineated and the dynamic effects onto the primary quantities, e.g. discharge coefficient, are quantified. Considering the motion of piston and valves leads to negative total pressure losses during the exhaust cycle, which cannot be observed at fixed valve lifts. Additionally, the induced flow structures develop differently when valve motion is taken into consideration, which leads to a significant disparity of mass flow rates evolving through the two individual valve ports. However, accounting for piston motion and limited valve motion, leads to a minor discharge coefficient alteration of about one to two percent

  6. Investigation of Dual-Vortical-Flow Hybrid Rocket Engine without Flame Holding Mechanism

    Directory of Open Access Journals (Sweden)

    A. Lai

    2018-01-01

    Full Text Available A 250 kgf thrust hybrid rocket engine was designed, tested, and verified in this work. Due to the injection and flow pattern of this engine, this engine was named dual-vortical-flow engine. This propulsion system uses N2O as oxidizer and HDPE as fuel. This engine was numerically investigated using a CFD tool that can handle reacting flow with finite-rate chemistry and coupled with the real-fluid model. The engine was further verified via a hot-fire test for 12 s. The ground Isp of the engine was 232 s and 221 s for numerical and hot-fire tests, respectively. An oscillation frequency with an order of 100 Hz was observed in both numerical and hot-fire tests with less than 5% of pressure oscillation. Swirling pattern on the fuel surface was also observed in both numerical and hot-fire test, which proves that this swirling dual-vortical-flow engine works exactly as designed. The averaged regression rate of the fuel surface was found to be 0.6~0.8 mm/s at the surface of disk walls and 1.5~1.7 mm/s at the surface of central core of the fuel grain.

  7. Gas core nuclear thermal rocket engine research and development in the former USSR

    International Nuclear Information System (INIS)

    Koehlinger, M.W.; Bennett, R.G.; Motloch, C.G.; Gurfink, M.M.

    1992-09-01

    Beginning in 1957 and continuing into the mid 1970s, the USSR conducted an extensive investigation into the use of both solid and gas core nuclear thermal rocket engines for space missions. During this time the scientific and engineering. problems associated with the development of a solid core engine were resolved. At the same time research was undertaken on a gas core engine, and some of the basic engineering problems associated with the concept were investigated. At the conclusion of the program, the basic principles of the solid core concept were established. However, a prototype solid core engine was not built because no established mission required such an engine. For the gas core concept, some of the basic physical processes involved were studied both theoretically and experimentally. However, no simple method of conducting proof-of-principle tests in a neutron flux was devised. This report focuses primarily on the development of the. gas core concept in the former USSR. A variety of gas core engine system parameters and designs are presented, along with a summary discussion of the basic physical principles and limitations involved in their design. The parallel development of the solid core concept is briefly described to provide an overall perspective of the magnitude of the nuclear thermal propulsion program and a technical comparison with the gas core concept

  8. Mass spectral chemical fingerprints reveal the molecular dependence of exhaust particulate matters on engine speeds.

    Science.gov (United States)

    Li, Yi; Zhang, Hua; Zhao, Zongshan; Tian, Yong; Liu, Kun; Jie, Feifan; Zhu, Liang; Chen, Huanwen

    2018-05-01

    Particulate matters (PMs) emitted by automobile exhaust contribute to a significant fraction of the global PMs. Extractive atmospheric pressure chemical ionization mass spectrometry (EAPCI-MS) was developed to explore the molecular dependence of PMs collected from exhaust gases produced at different vehicle engine speeds. The mass spectral fingerprints of the organic compounds embedded in differentially sized PMs (e.g., 0.22-0.45, 0.45-1.00, 1.00-2.00, 2.00-3.00, 3.00-5.00, and 5.00-10.00μm) generated at different engine speeds (e.g., 1000, 1500, 2000, 2500, and 3000r/min) were chemically profiled in the mass range of mass to charge ratio (m/z) 50-800. Organic compounds, including alcohols, aldehydes, and esters, were detected in all the PMs tested, with varied concentration levels for each individual PM sample. At relatively low engine speeds (≤1500r/min), the total amount of organic species embedded in PMs of 0.22-1.00μm was greater than in PMs of other sizes, while more organic species were found in PMs of 5.00-10.00μm at high engine speeds (≥3000r/min), indicating that the organic compounds distributed in different sizes of PMs strongly correlated with the engine speed. The experimental data showed that the EAPCI-MS technique enables molecular characterization of PMs in exhaust, revealing the chemical dependence of PMs on the engine speeds (i.e., the combustion conditions) of automobiles. Copyright © 2017. Published by Elsevier B.V.

  9. Fuel/propellant mixing in an open-cycle gas core nuclear rocket engine

    International Nuclear Information System (INIS)

    Guo, X.; Wehrmeyer, J.A.

    1997-01-01

    A numerical investigation of the mixing of gaseous uranium and hydrogen inside an open-cycle gas core nuclear rocket engine (spherical geometry) is presented. The gaseous uranium fuel is injected near the centerline of the spherical engine cavity at a constant mass flow rate, and the hydrogen propellant is injected around the periphery of the engine at a five degree angle to the wall, at a constant mass flow rate. The main objective is to seek ways to minimize the mixing of uranium and hydrogen by choosing a suitable injector geometry for the mixing of light and heavy gas streams. Three different uranium inlet areas are presented, and also three different turbulent models (k-var-epsilon model, RNG k-var-epsilon model, and RSM model) are investigated. The commercial CFD code, FLUENT, is used to model the flow field. Uranium mole fraction, axial mass flux, and radial mass flux contours are obtained. copyright 1997 American Institute of Physics

  10. Optical Measurement Techniques for Rocket Engine Testing and Component Applications: Digital Image Correlation and Dynamic Photogrammetry

    Science.gov (United States)

    Gradl, Paul

    2016-01-01

    NASA Marshall Space Flight Center (MSFC) has been advancing dynamic optical measurement systems, primarily Digital Image Correlation, for extreme environment rocket engine test applications. The Digital Image Correlation (DIC) technology is used to track local and full field deformations, displacement vectors and local and global strain measurements. This technology has been evaluated at MSFC through lab testing to full scale hotfire engine testing of the J-2X Upper Stage engine at Stennis Space Center. It has been shown to provide reliable measurement data and has replaced many traditional measurement techniques for NASA applications. NASA and AMRDEC have recently signed agreements for NASA to train and transition the technology to applications for missile and helicopter testing. This presentation will provide an overview and progression of the technology, various testing applications at NASA MSFC, overview of Army-NASA test collaborations and application lessons learned about Digital Image Correlation.

  11. Optimization of the stand for test of hybrid rocket engines of solid fuel

    Directory of Open Access Journals (Sweden)

    Zolotorev Nikolay

    2017-01-01

    Full Text Available In the paper the laboratory experimental stand of the hybrid rocket engine of solid fuel to study ballistic parameters of the engine at burning of high-energy materials in flow of hot gas is presented. Mixture of air with nitrogen with a specified content of active oxygen is used as a gaseous oxidizer. The experimental stand has modular design and consists of system of gas supply, system of heating of gas, system for monitoring gas parameters, to which a load cell with a model engine was connected. The modular design of the stand allows to change its configuration under specific objective. This experimental stand allows to conduct a wide range of the pilot studies at interaction of a hot stream of gas with samples high-energy materials.

  12. Metal particle emissions in the exhaust stream of diesel engines: an electron microscope study.

    Science.gov (United States)

    Liati, Anthi; Schreiber, Daniel; Dimopoulos Eggenschwiler, Panayotis; Arroyo Rojas Dasilva, Yadira

    2013-12-17

    Scanning electron microscopy and transmission electron microscopy were applied to investigate the morphology, mode of occurrence and chemical composition of metal particles (diesel ash) in the exhaust stream of a small truck outfitted with a typical after-treatment system (a diesel oxidation catalyst (DOC) and a downstream diesel particulate filter (DPF)). Ash consists of Ca-Zn-P-Mg-S-Na-Al-K-phases (lube-oil related), Fe, Cr, Ni, Sn, Pb, Sn (engine wear), and Pd (DOC coating). Soot agglomerates of variable sizes (1-5 μm, exceptionally 13 μm), rarely engine wear and escape into the atmosphere.

  13. Trade-off analysis of high-aspect-ratio-cooling-channels for rocket engines

    International Nuclear Information System (INIS)

    Pizzarelli, Marco; Nasuti, Francesco; Onofri, Marcello

    2013-01-01

    Highlights: • Aspect ratio has a significant effect on cooling efficiency and hydraulic losses. • Minimizing power loss is of paramount importance in liquid rocket engine cooling. • A suitable quasi-2D model is used to get fast cooling system analysis. • Trade-off with assigned weight, temperature, and channel height or wall thickness. • Aspect ratio is found that minimizes power loss in the cooling circuit. -- Abstract: High performance liquid rocket engines are often characterized by rectangular cooling channels with high aspect ratio (channel height-to-width ratio) because of their proven superior cooling efficiency with respect to a conventional design. However, the identification of the optimum aspect ratio is not a trivial task. In the present study a trade-off analysis is performed on a cooling channel system that can be of interest for rocket engines. This analysis requires multiple cooling channel flow calculations and thus cannot be efficiently performed by CFD solvers. Therefore, a proper numerical approach, referred to as quasi-2D model, is used to have fast and accurate predictions of cooling system properties. This approach relies on its capability of describing the thermal stratification that occurs in the coolant and in the wall structure, as well as the coolant warming and pressure drop along the channel length. Validation of the model is carried out by comparison with solutions obtained with a validated CFD solver. Results of the analysis show the existence of an optimum channel aspect ratio that minimizes the requested pump power needed to overcome losses in the cooling circuit

  14. To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

    International Nuclear Information System (INIS)

    Nam, Seung Hyun; Chang, Soon Heung

    2013-01-01

    The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application

  15. A reliability as an independent variable (RAIV) methodology for optimizing test planning for liquid rocket engines

    Science.gov (United States)

    Strunz, Richard; Herrmann, Jeffrey W.

    2011-12-01

    The hot fire test strategy for liquid rocket engines has always been a concern of space industry and agency alike because no recognized standard exists. Previous hot fire test plans focused on the verification of performance requirements but did not explicitly include reliability as a dimensioning variable. The stakeholders are, however, concerned about a hot fire test strategy that balances reliability, schedule, and affordability. A multiple criteria test planning model is presented that provides a framework to optimize the hot fire test strategy with respect to stakeholder concerns. The Staged Combustion Rocket Engine Demonstrator, a program of the European Space Agency, is used as example to provide the quantitative answer to the claim that a reduced thrust scale demonstrator is cost beneficial for a subsequent flight engine development. Scalability aspects of major subsystems are considered in the prior information definition inside the Bayesian framework. The model is also applied to assess the impact of an increase of the demonstrated reliability level on schedule and affordability.

  16. To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application.

  17. An optical method for measuring exhaust gas pressure from an internal combustion engine at high speed.

    Science.gov (United States)

    Leach, Felix C P; Davy, Martin H; Siskin, Dmitrij; Pechstedt, Ralf; Richardson, David

    2017-12-01

    Measurement of exhaust gas pressure at high speed in an engine is important for engine efficiency, computational fluid dynamics analysis, and turbocharger matching. Currently used piezoresistive sensors are bulky, require cooling, and have limited lifetimes. A new sensor system uses an interferometric technique to measure pressure by measuring the size of an optical cavity, which varies with pressure due to movement of a diaphragm. This pressure measurement system has been used in gas turbine engines where the temperatures and pressures have no significant transients but has never been applied to an internal combustion engine before, an environment where both temperature and pressure can change rapidly. This sensor has been compared with a piezoresistive sensor representing the current state-of-the-art at three engine operating points corresponding to both light load and full load. The results show that the new sensor can match the measurements from the piezoresistive sensor except when there are fast temperature swings, so the latter part of the pressure during exhaust blowdown is only tracked with an offset. A modified sensor designed to compensate for these temperature effects is also tested. The new sensor has shown significant potential as a compact, durable sensor, which does not require external cooling.

  18. Exhaust temperature analysis of four stroke diesel engine by using MWCNT/Water nanofluids as coolant

    Science.gov (United States)

    Muruganandam, M.; Mukesh Kumar, P. C.

    2017-10-01

    There has been a continuous improvement in designing of cooling system and in quality of internal combustion engine coolants. The liquid engine coolant used in early days faced many difficulties such as low boiling, freezing points and inherently poor thermal conductivity. Moreover, the conventional coolants have reached their limitations of heat dissipating capacity. New heat transfer fluids have been developed and named as nanofluids to try to replace traditional coolants. Moreover, many works are going on the application of nanofluids to avail the benefits of them. In this experimental investigation, 0.1, 0.3 and 0.5% volume concentrations of multi walled carbon nanotube (MWCNT)/water nanofluids have been prepared by two step method with surfactant and is used as a coolant in four stroke single cylinder diesel engine to assess the exhaust temperature of the engine. The nanofluid prepared is characterized with scanning electron microscope (SEM) to confirm uniform dispersion and stability of nanotube with zeta potential analyzer. Experimental tests are performed by various mass flow rate such as 270 300 330 LPH (litre per hour) of coolant nanofluids and by changing the load in the range of 0 to 2000 W and by keeping the engine speed constant. It is found that the exhaust temperature decreases by 10-20% when compared to water as coolant at the same condition.

  19. Performance and exhaust emission characteristics of direct-injection Diesel engine when operating on shale oil

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys

    2005-01-01

    This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine when running on Diesel fuel and shale oil that is produced in Estonia from local oil shale. The purpose of this research is to investigate the possibility of practical usage of the shale oil as the alternative fuel for a high speed Diesel engine as well as to evaluate the combustion efficiency, brake specific fuel consumption, emission composition changes and the smoke opacity of the exhausts. Test results show that when fuelling a fully loaded engine with shale oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.3% and 20.4%. However, the brake thermal efficiencies do not differ widely and their maximum values remain equal to 0.36-0.37 for Diesel fuel and 0.32-0.33 for shale oil. The total nitrogen oxide emissions from the shale oil at engine partial loads remain considerably lower although when running at the maximum torque and rated power, the NO x emissions become correspondingly higher by 21.8% and 27.6%. The smoke opacity of the fully loaded engine at a wide range of speeds is lower by 30-35%, whereas the carbon monoxide and unburned hydrocarbon emissions in the exhausts at moderate and full load regimes do not undergo significant changes

  20. An optical method for measuring exhaust gas pressure from an internal combustion engine at high speed

    Science.gov (United States)

    Leach, Felix C. P.; Davy, Martin H.; Siskin, Dmitrij; Pechstedt, Ralf; Richardson, David

    2017-12-01

    Measurement of exhaust gas pressure at high speed in an engine is important for engine efficiency, computational fluid dynamics analysis, and turbocharger matching. Currently used piezoresistive sensors are bulky, require cooling, and have limited lifetimes. A new sensor system uses an interferometric technique to measure pressure by measuring the size of an optical cavity, which varies with pressure due to movement of a diaphragm. This pressure measurement system has been used in gas turbine engines where the temperatures and pressures have no significant transients but has never been applied to an internal combustion engine before, an environment where both temperature and pressure can change rapidly. This sensor has been compared with a piezoresistive sensor representing the current state-of-the-art at three engine operating points corresponding to both light load and full load. The results show that the new sensor can match the measurements from the piezoresistive sensor except when there are fast temperature swings, so the latter part of the pressure during exhaust blowdown is only tracked with an offset. A modified sensor designed to compensate for these temperature effects is also tested. The new sensor has shown significant potential as a compact, durable sensor, which does not require external cooling.

  1. Turbulent Mixing of Primary and Secondary Flow Streams in a Rocket-Based Combined Cycle Engine

    Science.gov (United States)

    Cramer, J. M.; Greene, M. U.; Pal, S.; Santoro, R. J.; Turner, Jim (Technical Monitor)

    2002-01-01

    This viewgraph presentation gives an overview of the turbulent mixing of primary and secondary flow streams in a rocket-based combined cycle (RBCC) engine. A significant RBCC ejector mode database has been generated, detailing single and twin thruster configurations and global and local measurements. On-going analysis and correlation efforts include Marshall Space Flight Center computational fluid dynamics modeling and turbulent shear layer analysis. Potential follow-on activities include detailed measurements of air flow static pressure and velocity profiles, investigations into other thruster spacing configurations, performing a fundamental shear layer mixing study, and demonstrating single-shot Raman measurements.

  2. A highly efficient six-stroke internal combustion engine cycle with water injection for in-cylinder exhaust heat recovery

    International Nuclear Information System (INIS)

    Conklin, James C.; Szybist, James P.

    2010-01-01

    A concept adding two strokes to the Otto or Diesel engine cycle to increase fuel efficiency is presented here. It can be thought of as a four-stroke Otto or Diesel cycle followed by a two-stroke heat recovery steam cycle. A partial exhaust event coupled with water injection adds an additional power stroke. Waste heat from two sources is effectively converted into usable work: engine coolant and exhaust gas. An ideal thermodynamics model of the exhaust gas compression, water injection and expansion was used to investigate this modification. By changing the exhaust valve closing timing during the exhaust stroke, the optimum amount of exhaust can be recompressed, maximizing the net mean effective pressure of the steam expansion stroke (MEP steam ). The valve closing timing for maximum MEP steam is limited by either 1 bar or the dew point temperature of the expansion gas/moisture mixture when the exhaust valve opens. The range of MEP steam calculated for the geometry of a conventional gasoline engine and is from 0.75 to 2.5 bars. Typical combustion mean effective pressures (MEP combustion ) of naturally aspirated gasoline engines are up to 10 bar, thus this concept has the potential to significantly increase the engine efficiency and fuel economy.

  3. Another Look at Rocket Thrust

    Science.gov (United States)

    Hester, Brooke; Burris, Jennifer

    2012-01-01

    Rocket propulsion is often introduced as an example of Newton's third law. The rocket exerts a force on the exhaust gas being ejected; the gas exerts an equal and opposite force--the thrust--on the rocket. Equivalently, in the absence of a net external force, the total momentum of the system, rocket plus ejected gas, remains constant. The law of…

  4. Effects of the biodiesel blend fuel on aldehyde emissions from diesel engine exhaust

    Science.gov (United States)

    Peng, Chiung-Yu; Yang, Hsi-Hsien; Lan, Cheng-Hang; Chien, Shu-Mei

    Interest in use of biodiesel fuels derived from vegetable oils or animal fats as alternative fuels for petroleum-based diesels has increased due to biodiesels having similar properties of those of diesels, and characteristics of renewability, biodegradability and potential beneficial effects on exhaust emissions. Generally, exhaust emissions of regulated pollutants are widely studied and the results favor biodiesels on CO, HC and particulate emissions; however, limited and inconsistent data are showed for unregulated pollutants, such as carbonyl compounds, which are also important indicators for evaluating available vehicle fuels. For better understanding biodiesel, this study examines the effects of the biodiesel blend fuel on aldehyde chemical emissions from diesel engine exhausts in comparison with those from the diesel fuel. Test engines (Mitsubishi 4M40-2AT1) with four cylinders, a total displacement of 2.84 L, maximum horsepower of 80.9 kW at 3700 rpm, and maximum torque of 217.6 N m at 2000 rpm, were mounted and operated on a Schenck DyNAS 335 dynamometer. Exhaust emission tests were performed several times for each fuel under the US transient cycle protocol from mileages of 0-80,000 km with an interval of 20,000 km, and two additional measurements were carried out at 40,000 and 80,000 km after maintenance, respectively. Aldehyde samples were collected from diluted exhaust by using a constant volume sampling system. Samples were extracted and analyzed by the HPLC/UV system. Dominant aldehydes of both fuels' exhausts are formaldehyde and acetaldehyde. These compounds together account for over 75% of total aldehyde emissions. Total aldehyde emissions for B20 (20% waste cooking oil biodiesel and 80% diesel) and diesel fuels are in the ranges of 15.4-26.9 mg bhp-h -1 and 21.3-28.6 mg bhp-h -1, respectively. The effects of increasing mileages and maintenance practice on aldehyde emissions are insignificant for both fuels. B20 generates slightly less emission than

  5. Exhaust Recirculation Control for Reduction of NOx from Large Two-Stroke Diesel Engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder

    Increased awareness of the detrimental effects on climate, ecosystems and human health have led to numerous restrictions of the emissions from internal combustion engines. Recently the International Maritime Organization has introduced the Tier III standard, which includes a significantly stricter...... the automotive industry, but have only recently been introduced commercially to large two-stroke diesel engines. Recirculation of exhaust gas to the cylinders lowers the oxygen availability and increases the heat capacity during combustion, which in turn leads to less formation of NOx. Experience shows...... of the Tier III standard, while still maintaining maneuverability performance without smoke formation. The design methods acknowledge that engine specific parameter tuning is a scarce resource in the industry and controller complexity is kept to a minimum. An existing dynamic model of the engine and EGR...

  6. Operation of a cryogenic rocket engine an outline with down-to-earth and up-to-space remarks

    CERN Document Server

    Kitsche, Wolfgang

    2010-01-01

    This book presents the operational aspects of the rocket engine on a test facility. It will be useful to engineers and scientists who are in touch with the test facility. To aerospace students it shall provide an insight of the job on the test facility. And to interest readers it shall provide an impression of this thrilling area of aerospace.

  7. Effect of hydroxy (HHO) gas addition on performance and exhaust emissions in compression ignition engines

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Ali Can; Uludamar, Erinc; Aydin, Kadir [Department of Mechanical Engineering, Cukurova University, 01330 Adana (Turkey)

    2010-10-15

    In this study, hydroxy gas (HHO) was produced by the electrolysis process of different electrolytes (KOH{sub (aq)}, NaOH{sub (aq)}, NaCl{sub (aq)}) with various electrode designs in a leak proof plexiglass reactor (hydrogen generator). Hydroxy gas was used as a supplementary fuel in a four cylinder, four stroke, compression ignition (CI) engine without any modification and without need for storage tanks. Its effects on exhaust emissions and engine performance characteristics were investigated. Experiments showed that constant HHO flow rate at low engine speeds (under the critical speed of 1750 rpm for this experimental study), turned advantages of HHO system into disadvantages for engine torque, carbon monoxide (CO), hydrocarbon (HC) emissions and specific fuel consumption (SFC). Investigations demonstrated that HHO flow rate had to be diminished in relation to engine speed below 1750 rpm due to the long opening time of intake manifolds at low speeds. This caused excessive volume occupation of hydroxy in cylinders which prevented correct air to be taken into the combustion chambers and consequently, decreased volumetric efficiency was inevitable. Decreased volumetric efficiency influenced combustion efficiency which had negative effects on engine torque and exhaust emissions. Therefore, a hydroxy electronic control unit (HECU) was designed and manufactured to decrease HHO flow rate by decreasing voltage and current automatically by programming the data logger to compensate disadvantages of HHO gas on SFC, engine torque and exhaust emissions under engine speed of 1750 rpm. The flow rate of HHO gas was measured by using various amounts of KOH, NaOH, NaCl (catalysts). These catalysts were added into the water to diminish hydrogen and oxygen bonds and NaOH was specified as the most appropriate catalyst. It was observed that if the molality of NaOH in solution exceeded 1% by mass, electrical current supplied from the battery increased dramatically due to the too much

  8. Effects of exhaust gas recirculation in diesel engines featuring late PCCI type combustion strategies

    International Nuclear Information System (INIS)

    D’Ambrosio, S.; Ferrari, A.

    2015-01-01

    Highlights: • The effects that a high EGR rate can have on PCCI type combustion strategies have been analyzed. • The dependence of engine emissions and combustion noise on EGR has been addressed. • The time histories of the main in-cylinder variables have been plotted for different EGR rates. - Abstract: The influence of exhaust gas recirculation (EGR) has been analyzed considering experimental results obtained from a Euro 5 diesel engine calibrated with an optimized pilot-main double injection strategy. The engine features a late premixed charge compression ignition (PCCI) type combustion mode. Different steady-state key-points that are representative of the engine application in a passenger car over the New European Driving Cycle (NEDC) have been studied. The engine was fully instrumented to obtain a complete overview of the most important variables. The pressure time history in the combustion chamber has been measured to perform calculations with single and three-zone combustion diagnostic models. These models allow the in-cylinder emissions and the temperature of the burned and unburned zones to be evaluated as functions of the crankshaft angle. The EGR mass fraction was experimentally varied within the 0–50% range. The results of the investigation have shown the influence that high EGR rates can have on intake and exhaust temperatures, in-cylinder pressure and heat release rate time histories, engine-out emissions (CO, HC, NO_x, soot), brake specific fuel consumption and combustion noise for a PCCI type combustion strategy. The outputs of the diagnostic models have been used to conduct a detailed analysis of the cause-and-effect relationships between the EGR rate variations and the engine performance. Finally, the effect of the EGR on the cycle-to-cycle variability of the engine torque has been experimentally investigated.

  9. Development of an Organic Rankine Cycle system for exhaust energy recovery in internal combustion engines

    Science.gov (United States)

    Cipollone, Roberto; Bianchi, Giuseppe; Gualtieri, Angelo; Di Battista, Davide; Mauriello, Marco; Fatigati, Fabio

    2015-11-01

    Road transportation is currently one of the most influencing sectors for global energy consumptions and CO2 emissions. Nevertheless, more than one third of the fuel energy supplied to internal combustion engines is still rejected to the environment as thermal waste at the exhaust. Therefore, a greater fuel economy might be achieved recovering the energy from exhaust gases and converting it into useful power on board. In the current research activity, an ORC-based energy recovery system was developed and coupled with a diesel engine. The innovative feature of the recovery power unit relies upon the usage of sliding vane rotary machines as pump and expander. After a preliminary exhaust gas mapping, which allowed to assess the magnitude of the thermal power to be recovered, a thermodynamic analysis was carried out to design the ORC system and the sliding vane machines using R236fa as working fluid. An experimental campaign was eventually performed at different operating regimes according to the ESC procedure and investigated the recovery potential of the power unit at design and off-design conditions. Mechanical power recovered ranged from 0.7 kW up to 1.9 kW, with an overall cycle efficiency from 3.8% up to 4.8% respectively. These results candidate sliding vane machines as efficient and reliable devices for waste heat recovery applications.

  10. Prehistory and state of catalytic exhaust gas detoxification of vehicle engines

    Energy Technology Data Exchange (ETDEWEB)

    Pischinger, F

    1985-01-01

    The application of catalyst techniques to exhaust gas detoxification of car engines has a prehistory of about 60 years. There were important attempts at further development in the 1940's and 1950's in connection with efforts to comply with the legal measures in California caused by the smog problem in Los Angeles. The technical difficulties had been overcome by the mid-1970's, so that catalytic converters could be introduced into mass production of cars in the USA. Their function was first mainly limited to oxidation of noxious substances in the exhaust gas. Catalysts were first used to reduce nitrogen oxide emission in 1977. The 3 way catalyst now used in mass production in the USA permits the simultaneous reduction of all three important types of noxious substances emitted from petrol engines. In order to ensure the most favourable composition of the exhaust gas for this purpose, the 3 way catalyst is combined with electronic control of the formation of the mixture. The catalytic converter for cars represents by far the most economically important industrial application of catalyst techniques today. There is not other alternative for achieving the low emission of noxious substances which can be reached by this technique. (HW).

  11. Development and analysis of startup strategies for particle bed nuclear rocket engine

    Science.gov (United States)

    Suzuki, David E.

    1993-06-01

    The particle bed reactor (PBR) nuclear thermal propulsion rocket engine concept is the focus of the Air Force's Space Nuclear Thermal Propulsion program. While much progress has been made in developing the concept, several technical issues remain. Perhaps foremost among these concerns is the issue of flow stability through the porous, heated bed of fuel particles. There are two complementary technical issues associated with this concern: the identification of the flow stability boundary and the design of the engine controller to maintain stable operation. This thesis examines a portion of the latter issue which has yet to be addressed in detail. Specifically, it develops and analyzes general engine system startup strategies which maintain stable flow through the PBR fuel elements while reaching the design conditions as quickly as possible. The PBR engine studies are conducted using a computer model of a representative particle bed reactor and engine system. The computer program utilized is an augmented version of SAFSIM, an existing nuclear thermal propulsion modeling code; the augmentation, dubbed SAFSIM+, was developed by the author and provides a more complete engine system modeling tool.

  12. IDI diesel engine performance and exhaust emission analysis using biodiesel with an artificial neural network (ANN

    Directory of Open Access Journals (Sweden)

    K. Prasada Rao

    2017-09-01

    Full Text Available Biodiesel is receiving increasing attention each passing day because of its fuel properties and compatibility. This study investigates the performance and emission characteristics of single cylinder four stroke indirect diesel injection (IDI engine fueled with Rice Bran Methyl Ester (RBME with Isopropanol additive. The investigation is done through a combination of experimental data analysis and artificial neural network (ANN modeling. The study used IDI engine experimental data to evaluate nine engine performance and emission parameters including Exhaust Gas Temperature (E.G.T, Brake Specific Fuel Consumption (BSFC, Brake Thermal Efficiency (B.The and various emissions like Hydrocarbons (HC, Carbon monoxide (CO, Carbon dioxide (CO2, Oxygen (O2, Nitrogen oxides (NOX and smoke. For the ANN modeling standard back propagation algorithm was found to be the optimum choice for training the model. A multi-layer perception (MLP network was used for non-linear mapping between the input and output parameters. It was found that ANN was able to predict the engine performance and exhaust emissions with a correlation coefficient of 0.995, 0.980, 0.999, 0.985, 0.999, 0.999, 0.980, 0.999, and 0.999 for E.G.T, BSFC, B.The, HC, O2, CO2, CO, NOX, smoke respectively.

  13. Experimental Study on the Plasma Purification for Diesel Engine Exhaust Gas

    Science.gov (United States)

    Chen, Jing; Zu, Kan; Wang, Mei

    2018-02-01

    It is known that the use of ternary catalysis is capable of significantly reducing the emission of pollutants from petrol vehicles. However, the disadvantages such as the temperature and other limitations make it unsuitable for diesel engines. The plasma-assisted catalyst technology has been applied in dealing with the diesel exhaust in the experiment in order to do further research on the effects of plasma in exhaust processing. The paper not only includes the experimental observation on the change of particle concentration after the operation of purification device, but also builds the kinetic model of chemical reactions to simulate the reactions of nitrogen oxides in plasma through using the software of Matlab, then compares the calculation results with experimental samples and finally gets some useful conclusions in practice.

  14. A parametric design of compact exhaust manifold junction in heavy duty diesel engine using CFD

    Directory of Open Access Journals (Sweden)

    Naeimi Hessamedin

    2011-01-01

    Full Text Available Nowadays, computational fluid dynamics codes (CFD are prevalently used to simulate the gas dynamics in many fluid piping systems such as steam and gas turbines, inlet and exhaust in internal combustion engines. In this paper, a CFD software is used to obtain the total energy losses in adiabatic compressible flow at compact exhaust manifold junction. A steady state onedimensional adiabatic compressible flow with friction model has been applied to subtract the straight pipe friction losses from the total energy losses. The total pressure loss coefficient has been related to the extrapolated Mach number in the common branch and to the mass flow rate ratio between branches at different flow configurations, in both combining and dividing flows. The study indicate that the numerical results were generally in good agreement with those of experimental data from the literature and will be applied as a boundary condition in one-dimensional global simulation models of fluid systems in which these components are present.

  15. Investigation of diesel engine for low exhaust emissions with different combustion chambers

    Directory of Open Access Journals (Sweden)

    Ghodke Pundlik R.

    2015-01-01

    Full Text Available Upcoming stringent Euro-6 emission regulations for passenger vehicle better fuel economy, low cost are the key challenges for engine development. In this paper, 2.2L, multi cylinder diesel engine have been tested for four different piston bowls designed for compression ratio of CR 15.5 to improve in cylinder performance and reduce emissions. These combustion chambers were verified in CFD at two full load points. 14 mode points have been derived using vehicle model run in AVL CRUISE software as per NEDC cycle based on time weightage factor. Base engine with compression ratio CR16.5 for full load performance and 14-mode points on Engine test bench was taken as reference for comparison. The bowl with flat face on bottom corner has shown reduction 25% and 12 % NOx emissions at 1500 and 3750 rpm full load points at same level of Soot emissions. Three piston bowls were tested for full load performance and 14 mode points on engine test bench and combustion chamber ‘C’ has shown improvement in thermal efficiency by 0.8%. Combinations of cooled EGR and combustion chamber ‘C’ with geometrical changes in engine have reduced exhaust NOx, soot and CO emissions by 22%, 9 % and 64 % as compared to base engine at 14 mode points on engine test bench.

  16. Ion beam analyses of particulate matter in exhaust gas of a ship diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Furuyama, Yuichi, E-mail: furuyama@maritime.kobe-u.ac.jp [Graduate School of Maritime Sciences, Kobe University, Fukae-Minami-Machi, Higashinada-Ku, Kobe 658-0022 (Japan); Fujita, Hirotsugu; Taniike, Akira; Kitamura, Akira [Graduate School of Maritime Sciences, Kobe University, Fukae-Minami-Machi, Higashinada-Ku, Kobe 658-0022 (Japan)

    2011-12-15

    There is an urgent need to reduce emission of the particulate matter (PM) in the exhaust gas from ship diesel engines causing various health hazards and serious environmental pollution. Usually the heavy fuel oil (HFO) for ships is of low quality, and contains various kinds of impurities. Therefore, the emission of PM along with exhaust gas from ship diesel engines is one of the most serious environmental issues. However, the PM fundamental properties are not well known. Therefore, it is important to perform elemental analysis of the PM. The HFO contains sulfur with a relatively high concentration of a few percent. It is important to make quantitative measurements of sulfur in the PM, because this element is poisonous for the human body. In the present work, PM samples were collected from exhaust gas of a test engine, and RBS and PIXE analyses were applied successfully to quantitative analysis of the PM samples. The RBS analysis enabled quantitative analysis of sulfur and carbon in the collected PM, while heavier elements such as vanadium and iron were analyzed quantitatively with the PIXE analysis. It has been found that the concentration ratio of sulfur to carbon was between 0.007 and 0.012, and did not strongly depend on the output power of the engine. The S/C ratio is approximately equal to the original composition of the HFO used in the present work, 0.01. From the known conversion ratio 0.015 of sulfur in the HFO to sulfates, the conversion ratio of carbon in the HFO to the PM is found to be 0.01-0.02 by the RBS measurements. On the other hand, the PIXE analysis revealed a vanadium enrichment of one order of magnitude in the PM.

  17. Designing a heat pipe to improve the exhaust emissions from petrol engines

    International Nuclear Information System (INIS)

    Elmabrouk, A.M.

    2010-01-01

    The national engineering Laboratory and the Shell research laboratory have co-operated in applying the heat pipe to the problem of exhaust emission from petrol engine. It is known that the carbon monoxide CO, un-burnt hydrocarbons (H x C y ) and oxides of Nitrogen (NO x ) content of the exhaust will vary with air to fuel ratio as shown in figure (1), in a conventional car engine the maximum efficiency is achieved at 15:1 and maximum power is obtained at 12:1. It's known that as the air fuel ratio increases, the CO content decreases and H x C y , NO x go through a minimum and maximum respectively. A considerable important in both CO and NO x content could be chivied by selecting a very weak mixture, but this not possible in a standard engine carburetor system due to the ignition difficulty, because the fuel is not fully vaporized, and because the fuel is not distributed equally between the cylinders and the vapor content is not as high as it should be due to the pressure of liquid fuel. This problem could be solved by designing a heat pipe that can transferring a certain quantities of heat from the exhaust to the induction manifold at the carburetor outlet as shown in figure (2). Under this condition a mixture as lean as 22:1 will ignite with out difficulty. In this paper, a complete design of heat pipe is carried out, taking into account the necessary criteria to decide various geometrical parameters. The design has been carried out using basic formulas in thermodynamics, heat transfer and physics. The result of this design have been checked for various practical limits. (author)

  18. An improved heat transfer configuration for a solid-core nuclear thermal rocket engine

    International Nuclear Information System (INIS)

    Clark, J.S.; Walton, J.T.; Mcguire, M.L.

    1992-07-01

    Interrupted flow, impingement cooling, and axial power distribution are employed to enhance the heat-transfer configuration of a solid-core nuclear thermal rocket engine. Impingement cooling is introduced to increase the local heat-transfer coefficients between the reactor material and the coolants. Increased fuel loading is used at the inlet end of the reactor to enhance heat-transfer capability where the temperature differences are the greatest. A thermal-hydraulics computer program for an unfueled NERVA reactor core is employed to analyze the proposed configuration with attention given to uniform fuel loading, number of channels through the impingement wafers, fuel-element length, mass-flow rate, and wafer gap. The impingement wafer concept (IWC) is shown to have heat-transfer characteristics that are better than those of the NERVA-derived reactor at 2500 K. The IWC concept is argued to be an effective heat-transfer configuration for solid-core nuclear thermal rocket engines. 11 refs

  19. Influence of atomization quality modulation on flame dynamics in a hypergolic rocket engine

    Directory of Open Access Journals (Sweden)

    Moritz Schulze

    2016-09-01

    Full Text Available For the numerical evaluation of the thermoacoustic stability of rocket engines often hybrid methods are applied, which separate the computation of wave propagation in the combustor from the analysis of the flame response to acoustic perturbations. Closure requires a thermoacoustic feedback model which provides the heat release fluctuation in the source term of the employed wave transport equations. The influence of the acoustic fluctuations in the combustion chamber on the heat release fluctuations from the modulation of the atomization of the propellants in a hypergolic upper stage rocket engine is studied. Numerical modeling of a single injector provides the time mean reacting flow field. A network of transfer functions representing all aspects relevant for the feedback model is presented. Analytical models for the injector admittances and for the atomization transfer functions are provided. The dynamics of evaporation and combustion are studied numerically and the numerical results are analyzed. An analytical approximation of the computed flame transfer function is combined with the analytical models for the injector and the atomization quality to derive the feedback model for the wave propagation code. The evaluation of this model on the basis of the Rayleigh index reveals the thermoacoustic driving potential originating from the fluctuating spray quality.

  20. Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

    Directory of Open Access Journals (Sweden)

    T. F. Lyon

    Full Text Available Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C1 through C17, CO, CO2, NO, NOx, and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.

  1. Chemical composition and photochemical reactivity of exhaust from aircraft turbine engines

    Directory of Open Access Journals (Sweden)

    C. W. Spicer

    1994-08-01

    Full Text Available Assessment of the environmental impact of aircraft emissions is required by planners and policy makers. Seveal areas of concern are: 1. exposure of airport workers and urban residents to toxic chemicals emitted when the engines operate at low power (idle and taxi on the ground; 2. contributions to urban photochemical air pollution of aircraft volatile organic and nitrogen oxides emissions from operations around airports; and 3. emissions of nitrogen oxides and particles during high-altitude operation. The environmental impact of chemicals emitted from jet aircraft turbine engines has not been firmly established due to lack of data regarding emission rates and identities of the compounds emitted. This paper describes an experimental study of two different aircraft turbine engines designed to determine detailed organic emissions, as well as emissions of inorganic gases. Emissions were measured at several engine power settings. Measurements were made of detailed organic composition from C1 through C17, CO, CO2, NO, NOx, and polycyclic aromatic hydrocarbons. Measurements were made using a multi-port sampling pro be positioned directly behind the engine in the exhaust exit plane. The emission measurements have been used to determine the organic distribution by carbon number and the distribution by compound class at each engine power level. The sum of the organic species was compared with an independent measurement of total organic carbon to assess the carbon mass balance. A portion of the exhaust was captured and irradiated in outdoor smog chambers to assess the photochemical reactivity of the emissions with respect to ozone formation. The reactivity of emissions from the two engines was apportioned by chemical compound class.

  2. Effects of a biodiesel blend on energy distribution and exhaust emissions of a small CI engine

    International Nuclear Information System (INIS)

    Magno, Agnese; Mancaruso, Ezio; Vaglieco, Bianca Maria

    2015-01-01

    Highlights: • B20 does not affect the brake thermal efficiency and the engine energetic flows with respect to diesel fuel. • B20 is characterized by lower combustion noise than diesel fuel. • B20 emits lower CO, HC and PM in the most of the operating conditions. • A definite trend of NO x emissions for B20 with respect to diesel fuel was not found. • B20 emits more nuclei particles than diesel fuel. - Abstract: This paper investigates the energy distribution and the waste heat energy characteristics of a compression ignition engine for micro-cogeneration applications, at different engine speeds and loads. The experimental activity was carried out on a three-cylinder, 1028 cc, common-rail engine. Tests were performed with diesel fuel and a 20% v/v biodiesel blend (B20). The quantity and the quality of the waste heat energy were studied through energy and exergy analyses, respectively. Combustion characteristics were investigated by means of indicating data. Gaseous emissions were measured and particles were characterized in terms of number and size at exhaust. It was found out that the addition of 20% v/v of RME to diesel fuel does not affect significantly the brake fuel conversion efficiency and the energetic flows. On the other hand, biodiesel blend allows to reduce the combustion noise and the pollutants emissions in most of the operating conditions. A proper phasing of the injection strategy for the biodiesel blend could further reduce the exhaust emissions, mainly at high engine speeds. The results presented in this paper could be useful for the development of diesel engine based micro-cogeneration systems working at different engine speeds and loads

  3. Aero-Thermo-Structural Analysis of Inlet for Rocket Based Combined Cycle Engines

    Science.gov (United States)

    Shivakumar, K. N.; Challa, Preeti; Sree, Dave; Reddy, Dhanireddy R. (Technical Monitor)

    2000-01-01

    NASA has been developing advanced space transportation concepts and technologies to make access to space less costly. One such concept is the reusable vehicles with short turn-around times. The NASA Glenn Research Center's concept vehicle is the Trailblazer powered by a rocket-based combined cycle (RBCC) engine. Inlet is one of the most important components of the RBCC engine. This paper presents fluid flow, thermal, and structural analysis of the inlet for Mach 6 free stream velocity for fully supersonic and supercritical with backpressure conditions. The results concluded that the fully supersonic condition was the most severe case and the largest stresses occur in the ceramic matrix composite layer of the inlet cowl. The maximum tensile and the compressive stresses were at least 3.8 and 3.4, respectively, times less than the associated material strength.

  4. Two-phase flow in the cooling circuit of a cryogenic rocket engine

    Science.gov (United States)

    Preclik, D.

    1992-07-01

    Transient two-phase flow was investigated for the hydrogen cooling circuit of the HM7 rocket engine. The nuclear reactor code ATHLET/THESEUS was adapted to cryogenics and applied to both principal and prototype experiments for validation and simulation purposes. The cooling circuit two-phase flow simulation focused on the hydrogen prechilling and pump transient phase prior to ignition. Both a single- and a multichannel model were designed and employed for a valve leakage flow, a nominal prechilling flow, and a prechilling with a subsequent pump-transient flow. The latter case was performed in order to evaluate the difference between a nominal and a delayed turbo-pump start-up. It was found that an extension of the nominal prechilling sequence in the order of 1 second is sufficient to finally provide for liquid injection conditions of hydrogen which, as commonly known, is undesirable for smooth ignition and engine starting transients.

  5. Towards Rocket Engine Components with Increased Strength and Robust Operating Characteristics

    Science.gov (United States)

    Marcu, Bogdan; Hadid, Ali; Lin, Pei; Balcazar, Daniel; Rai, Man Mohan; Dorney, Daniel J.

    2005-01-01

    High-energy rotating machines, powering liquid propellant rocket engines, are subject to various sources of high and low cycle fatigue generated by unsteady flow phenomena. Given the tremendous need for reliability in a sustainable space exploration program, a fundamental change in the design methodology for engine components is required for both launch and space based systems. A design optimization system based on neural-networks has been applied and demonstrated in the redesign of the Space Shuttle Main Engine (SSME) Low Pressure Oxidizer Turbo Pump (LPOTP) turbine nozzle. One objective of the redesign effort was to increase airfoil thickness and thus increase its strength while at the same time detuning the vane natural frequency modes from the vortex shedding frequency. The second objective was to reduce the vortex shedding amplitude. The third objective was to maintain this low shedding amplitude even in the presence of large manufacturing tolerances. All of these objectives were achieved without generating any detrimental effects on the downstream flow through the turbine, and without introducing any penalty in performance. The airfoil redesign and preliminary assessment was performed in the Exploration Technology Directorate at NASA ARC. Boeing/Rocketdyne and NASA MSFC independently performed final CFD assessments of the design. Four different CFD codes were used in this process. They include WIL DCA T/CORSAIR (NASA), FLUENT (commercial), TIDAL (Boeing Rocketdyne) and, a new family (AardvarWPhantom) of CFD analysis codes developed at NASA MSFC employing LOX fluid properties and a Generalized Equation Set formulation. Extensive aerodynamic performance analysis and stress analysis carried out at Boeing Rocketdyne and NASA MSFC indicate that the redesign objectives have been fully met. The paper presents the results of the assessment analysis and discusses the future potential of robust optimal design for rocket engine components.

  6. Sustainability assessment of turbofan engine with mixed exhaust through exergetic approach

    Science.gov (United States)

    Saadon, S.; Redzuan, M. S. Mohd

    2017-12-01

    In this study, the theory, methods and example application are described for a CF6 high-bypass turbofan engine with mixed exhaust flow based on exergo-sustainable point of view. To determine exergetic sustainability index, the turbofan engine has to undergo detailed exergy analysis. The sustainability indicators reviewed here are the overall exergy efficiency of the system, waste exergy ratio, exergy destruction factor, environmental effect factor and the exergetic sustainability index. The results obtained for these parameters are 26.9%, 73.1%, 38.6%, 2.72 and 0.37, respectively, for the maximum take-off condition of the engine. These results would be useful to better understand the connection between the propulsion system parameters and their impact to the environment in order to make it more sustainable for future development.

  7. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines

    Science.gov (United States)

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-01-01

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the “engine-out” soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content. PMID:26580621

  8. Influence Of Aircraft Engine Exhaust Emissions At A Global Level And Preventive Measures

    Directory of Open Access Journals (Sweden)

    Jasna Golubić

    2004-07-01

    Full Text Available The work considers the differences in the aircraft engine exhaustemissions, as well as the impact of the emissions on theenvironment depending on several factors. These include theage of the engine, i. e. technical refinement, engine operating regimesat different thrusts during time periods: takeoff, climb,approach, etc. Also, the exhaust emissions do not have thesame influence on different atmospheric layers. The pollutantsemitted at higher altitudes during cruising have become agreater problem, although the volume of pollutants is smaller,due to the chemical complexity and sensitivity of these layers ascompared to the lower layers of atmosphere. One of the reasonswhy these problems have long remained outside the focus of interestof the environmentalists is that the air transport of goodsand people is performed at high altitudes, so that the pollutionof atmosphere does not present a direct threat to anyone, sincethe environment is being polluted at a global level and thereforeis more difficult to notice at the local level.

  9. Diesel engine exhaust gas recirculation--a review on advanced and novel concepts

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ming E-mail: mzheng@uwindsor.ca; Reader, Graham T.; Hawley, J. Gary

    2004-04-01

    Exhaust gas recirculation (EGR) is effective to reduce nitrogen oxides (NO{sub x}) from Diesel engines because it lowers the flame temperature and the oxygen concentration of the working fluid in the combustion chamber. However, as NO{sub x} reduces, particulate matter (PM) increases, resulting from the lowered oxygen concentration. When EGR further increases, the engine operation reaches zones with higher instabilities, increased carbonaceous emissions and even power losses. In this research, the paths and limits to reduce NO{sub x} emissions from Diesel engines are briefly reviewed, and the inevitable uses of EGR are highlighted. The impact of EGR on Diesel operations is analyzed and a variety of ways to implement EGR are outlined. Thereafter, new concepts regarding EGR stream treatment and EGR hydrogen reforming are proposed.

  10. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines.

    Science.gov (United States)

    Feulner, Markus; Hagen, Gunter; Müller, Andreas; Schott, Andreas; Zöllner, Christian; Brüggemann, Dieter; Moos, Ralf

    2015-11-13

    Soot sensors are required for on-board diagnostics (OBD) of automotive diesel particulate filters (DPF) to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the "engine-out" soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS) agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content.

  11. Conductometric Sensor for Soot Mass Flow Detection in Exhausts of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Markus Feulner

    2015-11-01

    Full Text Available Soot sensors are required for on-board diagnostics (OBD of automotive diesel particulate filters (DPF to detect filter failures. Widely used for this purpose are conductometric sensors, measuring an electrical current or resistance between two electrodes. Soot particles deposit on the electrodes, which leads to an increase in current or decrease in resistance. If installed upstream of a DPF, the “engine-out” soot emissions can also be determined directly by soot sensors. Sensors were characterized in diesel engine real exhausts under varying operation conditions and with two different kinds of diesel fuel. The sensor signal was correlated to the actual soot mass and particle number, measured with an SMPS. Sensor data and soot analytics (SMPS agreed very well, an impressing linear correlation in a double logarithmic representation was found. This behavior was even independent of the used engine settings or of the biodiesel content.

  12. Digital Image Correlation Techniques Applied to Large Scale Rocket Engine Testing

    Science.gov (United States)

    Gradl, Paul R.

    2016-01-01

    Rocket engine hot-fire ground testing is necessary to understand component performance, reliability and engine system interactions during development. The J-2X upper stage engine completed a series of developmental hot-fire tests that derived performance of the engine and components, validated analytical models and provided the necessary data to identify where design changes, process improvements and technology development were needed. The J-2X development engines were heavily instrumented to provide the data necessary to support these activities which enabled the team to investigate any anomalies experienced during the test program. This paper describes the development of an optical digital image correlation technique to augment the data provided by traditional strain gauges which are prone to debonding at elevated temperatures and limited to localized measurements. The feasibility of this optical measurement system was demonstrated during full scale hot-fire testing of J-2X, during which a digital image correlation system, incorporating a pair of high speed cameras to measure three-dimensional, real-time displacements and strains was installed and operated under the extreme environments present on the test stand. The camera and facility setup, pre-test calibrations, data collection, hot-fire test data collection and post-test analysis and results are presented in this paper.

  13. A Programmatic and Engineering Approach to the Development of a Nuclear Thermal Rocket for Space Exploration

    Science.gov (United States)

    Bordelon, Wayne J., Jr.; Ballard, Rick O.; Gerrish, Harold P., Jr.

    2006-01-01

    With the announcement of the Vision for Space Exploration on January 14, 2004, there has been a renewed interest in nuclear thermal propulsion. Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions; however, the cost to develop a nuclear thermal rocket engine system is uncertain. Key to determining the engine development cost will be the engine requirements, the technology used in the development and the development approach. The engine requirements and technology selection have not been defined and are awaiting definition of the Mars architecture and vehicle definitions. The paper discusses an engine development approach in light of top-level strategic questions and considerations for nuclear thermal propulsion and provides a suggested approach based on work conducted at the NASA Marshall Space Flight Center to support planning and requirements for the Prometheus Power and Propulsion Office. This work is intended to help support the development of a comprehensive strategy for nuclear thermal propulsion, to help reduce the uncertainty in the development cost estimate, and to help assess the potential value of and need for nuclear thermal propulsion for a human Mars mission.

  14. Investigation of microalgae HTL fuel effects on diesel engine performance and exhaust emissions using surrogate fuels

    International Nuclear Information System (INIS)

    Hossain, Farhad M.; Nabi, Md. Nurun; Rainey, Thomas J.; Bodisco, Timothy; Rahman, Md. Mostafizur; Suara, Kabir; Rahman, S.M.A.; Van, Thuy Chu; Ristovski, Zoran; Brown, Richard J.

    2017-01-01

    Highlights: • Development of a microalgae HTL surrogate of biocrude fuel using chemical compounds. • Physiochemical properties of surrogate blends were analysed. • Experimentally investigated diesel engine performance and emissions using surrogate fuels. • No significant changes in engine performance were observed with HTL surrogate blends. • Major emissions including PM, PN and CO were reduced significantly with increasing of NOx emission. - Abstract: This paper builds on previous work using surrogate fuel to investigate advanced internal combustion engine fuels. To date, a surrogate fuel of this nature has not been used for microalgae hydrothermal liquefaction (HTL) biocrude. This research used five different chemical groups found in microalgae HTL biocrude to design a surrogate fuel. Those five chemical groups constitute around 65% (by weight) of a microalgae biocrude produced by HTL. Weight percentage of the microalgae HTL biocrude chemical compounds were used to design the surrogate fuel, which was miscible with diesel at all percentages. The engine experiments were conducted on a EURO IIIA turbocharged common-rail direct-injection six-cylinder diesel engine to test engine performance and emissions. Exhaust emissions, including particulate matter and other gaseous emissions, were measured with the surrogate fuel and a reference diesel fuel. Experimental results showed that without significantly deteriorating engine performance, lower particulate mass, particulate number and CO emissions were observed with a penalty in NOx emissions for all surrogate blends compared to those of the reference diesel.

  15. Experimental analysis of diffusion absorption refrigerator driven by electrical heater and engine exhaust gas

    Directory of Open Access Journals (Sweden)

    Mohamed Izzedine Serge ADJIBADE

    2017-09-01

    Full Text Available This work presents an experimental study of H20-NH3-H2 diffusion absorption refrigeration under two types of energy sources, i.e. the conventional electric energy from grid (electric and exhaust gas from internal combustion engine. Dynamic method is used to evaluate the behavior of the components of the system for both energy sources. Results obtained show that the performance of each component under different types of energy sources is almost coherent. For the generator, the electrical heater system requires more time to warm up, around three minutes, compared to the 40 s for system running with exhaust gas. For the evaporator, the decreasing rate is higher for the exhaust gas source and it took only about two hours to reach steady-state while for the electrical heat, the steady-state is reached after about seven hours of operation. For both energy sources, the evaporation temperature stabilizes to 3 °C and the minimum temperature to boil off ammonia is around 140 °C.

  16. Device for the catalytic after-burning of exhaust gases in the exhaust gas system of an internal-combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Lange, K

    1975-06-19

    The invention deals with a device which protects the catalyst for the after-burning of exhaust gases against damage by high temperatures. When the catalyst temperature reaches a certain limiting value, a throttle is activated by an electrical control device influenced by a temperature sensor via a servomotor. The throttle valve opens a by-pass for the exhaust gases which had previously flowed through the system for catalytic after-burning. In order to prevent the throttle from rusting due to its rare use, it is regularly put into use after switching off the ignition of the internal-combustion engine by the still briefly present oil pressure in the engine via an oil pressure switch and the mentioned control device.

  17. High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, David; Singh, Jogender

    2014-01-01

    Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

  18. Rocket-Based Combined Cycle Engine Technology Development: Inlet CFD Validation and Application

    Science.gov (United States)

    DeBonis, J. R.; Yungster, S.

    1996-01-01

    A CFD methodology has been developed for inlet analyses of Rocket-Based Combined Cycle (RBCC) Engines. A full Navier-Stokes analysis code, NPARC, was used in conjunction with pre- and post-processing tools to obtain a complete description of the flow field and integrated inlet performance. This methodology was developed and validated using results from a subscale test of the inlet to a RBCC 'Strut-Jet' engine performed in the NASA Lewis 1 x 1 ft. supersonic wind tunnel. Results obtained from this study include analyses at flight Mach numbers of 5 and 6 for super-critical operating conditions. These results showed excellent agreement with experimental data. The analysis tools were also used to obtain pre-test performance and operability predictions for the RBCC demonstrator engine planned for testing in the NASA Lewis Hypersonic Test Facility. This analysis calculated the baseline fuel-off internal force of the engine which is needed to determine the net thrust with fuel on.

  19. Cooling Duct Analysis for Transpiration/Film Cooled Liquid Propellant Rocket Engines

    Science.gov (United States)

    Micklow, Gerald J.

    1996-01-01

    The development of a low cost space transportation system requires that the propulsion system be reusable, have long life, with good performance and use low cost propellants. Improved performance can be achieved by operating the engine at higher pressure and temperature levels than previous designs. Increasing the chamber pressure and temperature, however, will increase wall heating rates. This necessitates the need for active cooling methods such as film cooling or transpiration cooling. But active cooling can reduce the net thrust of the engine and add considerably to the design complexity. Recently, a metal drawing process has been patented where it is possible to fabricate plates with very small holes with high uniformity with a closely specified porosity. Such a metal plate could be used for an inexpensive transpiration/film cooled liner to meet the demands of advanced reusable rocket engines, if coolant mass flow rates could be controlled to satisfy wall cooling requirements and performance. The present study investigates the possibility of controlling the coolant mass flow rate through the porous material by simple non-active fluid dynamic means. The coolant will be supplied to the porous material by series of constant geometry slots machined on the exterior of the engine.

  20. Comparative study of different exhaust heat exchangers effect on the performance and exergy analysis of a diesel engine

    NARCIS (Netherlands)

    Hatami, M.; Boot, M.D.; Ganji, D.D.; Gorji-Bandpy, M.

    2015-01-01

    In this research, the effect of three designed heat exchangers on the performance of an OM314 diesel engine and its exergy balance is investigated. Vortex generator heat exchanger (HEX), optimized finned-tube HEX and non-optimized HEX are considered and mounted on the exhaust of diesel engine.

  1. Application of L.D.A. to measure instantaneous flow velocity field in the exhaust of a combustion engine

    International Nuclear Information System (INIS)

    Boutrif, M.S.; Thelliez, M.

    1993-01-01

    We present experimental results of instantaneous velocity measurement, which were obtained by application of the laser Doppler anemometry (L.D.A.) at the exhaust pipe of a reciprocating engine under real working conditions. First of all, we show that the instantaneous velocity is monodimensional along a straight exhaust pipe, and that the boundary layer develops within a 2 mm thickness. We also show that the cylinder discharges in two phases: the blow down period and the final part of exhaust stroke. We also make obvious, that the flow escapes very quickly: its velocity varies betwen -100 m/s and 200 m/s within a period shorter than 1 ms; thereby, we do record the acoustic resonance phenomenon, when the engine speed is greater than 3 000 rpm. Finally, we show that in the exhaust pipe the apparent fluctuation - i.e. the cyclic dispersion and the actual turbulence - may reach 15%. (orig.)

  2. Oxidative destruction of biomolecules by gasoline engine exhaust products and detoxifying effects of the three-way catalytic converter.

    Science.gov (United States)

    Blaurock, B; Hippeli, S; Metz, N; Elstner, E F

    1992-01-01

    Aqueous solutions of engine exhaust condensation products were derived from cars powered by diesel or four-stroke gasoline engines (with and without three-way catalytic converter). The cars were operated on a static test platform. Samples of the different exhaust solutions accumulated in a Grimmer-type distillation trap (VDI 3872) during standard test programs (Federal Test Procedure) were incubated with important biomolecules. As indicators of reactive oxygen species or oxidative destruction, ascorbic acid, cysteine, glutathione, serum albumin, the enzymes glycerinaldehyde phosphate dehydrogenase and xanthine oxidase, and the oxygen free-radical indicator keto-methylthiobutyrate were used. During and after the incubations, oxygen activation (consumption) and oxidative destruction were determined. Comparison of the oxidative activities of the different types of exhaust condensates clearly showed that the exhaust condensate derived from the four-stroke car equipped with a three-way catalytic converter exhibited by far the lowest oxidative and destructive power.

  3. Performance and Exhaust Emissions in a Natural-Gas Fueled Dual-Fuel Engine

    Science.gov (United States)

    Shioji, Masahiro; Ishiyama, Takuji; Ikegami, Makoto; Mitani, Shinichi; Shibata, Hiroaki

    In order to establish the optimum fueling in a natural gas fueled dual fuel engine, experiments were done for some operational parameters on the engine performances and the exhaust emissions. The results show that the pilot fuel quantity should be increased and its injection timing should be advanced to suppress unburned hydrocarbon emission in the middle and low output range, while the quantity should be reduced and the timing retarded to avoid onset of knock at high loads. Unburned hydrocarbon emission and thermal efficiency are improved by avoiding too lean natural gas mixture by restricting intake charge air. However, the improvement is limited because the ignition of pilot fuel deteriorates with excessive throttling. It is concluded that an adequate combination of throttle control and equivalence ratio ensures low hydrocarbon emission and the thermal efficiency comparable to diesel operation.

  4. Influence of metallic based fuel additives on performance and exhaust emissions of diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Ali [Tarsus Technical Education Faculty, Mersin University, 33500 Mersin (Turkey); Guerue, Metin, E-mail: mguru@gazi.edu.t [Engineering and Architectural Faculty, Gazi University, 06570 Maltepe, Ankara (Turkey); Altiparmak, Duran [Technical Education Faculty, Gazi University, 06500 Ankara (Turkey)

    2011-01-15

    In this experimental study, influence of the metallic-based additives on fuel consumption and exhaust emissions of diesel engine were investigated. The metallic-based additives were produced by synthesizing of resin acid (abietic acid) with MnO{sub 2} or MgO. These additives were doped into diesel fuel at the rate of 8 {mu}mol/l and 16 {mu}mol/l for preparing test fuels. Both additives improved the properties of diesel fuel such as viscosity, flash point, cloud point and pour point. The fuels with and without additives were tested in a direct injection diesel engine at full load condition. Maximum reduction of specific fuel consumption was recorded as 4.16%. CO emission and smoke opacity decreased by 16.35% and by 29.82%, respectively. NO{sub x} emission was measured higher and CO{sub 2} emission was not changed considerably with the metallic-based additives.

  5. Measurement of nitrogen species NO{sub y} at the exhaust of an aircraft engine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Ristori, A [Office National d` Etudes et de Recherches Aerospatiales (ONERA), Palaiseau (France); Baudoin, C [Societe Nationale d` Etude et de Construction de Moteurs d` Aviation (SNECMA), Villaroche (France)

    1998-12-31

    A research programme named AEROTRACE was supported by the EC (CEC contract AERA-CT94-0003) in order to investigate trace species measurements at the exhaust of aero-engines. Within this project, NO{sub y}, NO, HNO{sub 3} and HONO were measured at the exhaust of aircraft engine combustors. Major species (NO{sub y},NO) were measured by using a chemiluminescence instrument. Minor species (HNO{sub 3},HONO) were measured by using filter packs. Two combustors were tested under various running conditions; the first one at ONERA (Task 2) and the second one at DRA (Task 5). Results show that EI{sub NOy} < 50 g/kg, EI{sub HNO3} < 0.2 g/kg and EI{sub HONO} < 0.55 g/kg. Regarding ratios, (HNO{sub 3})/(NO{sub y}) < 0.5%, (HONO)/(NO{sub y}) < 8%, (HONO)/(NO{sub 2}) {approx} 19.2%, and (HNO{sub 3})/(NO{sub 2}) {approx} 0.8% was found. (author) 9 refs.

  6. Optical system for CO and NO gas detection in the exhaust manifold of combustion engines

    International Nuclear Information System (INIS)

    Mello, M.; De Vittorio, M.; Passaseo, A.; Lomascolo, M.; De Risi, A.

    2007-01-01

    The experimental characterization of an innovative optical system for detection of carbon monoxide (CO) and nitride oxide (NO) in the exhaust manifold of otto and diesel engines is reported. A photodetector based on gallium nitride (GaN) and an UV light source are integrated in a chamber of analysis and form the detection system. The UV light source, consisting of a spark produced by an arc discharge, induces electronic transitions in the gas molecules flowing between the light source and the GaN photodetector. The transitions modify the fraction of light in the UV spectral region which is detected by the GaN photodetector, as a function of the species concentration. By means of its structural properties, gallium nitride (GaN) allows to operate at high temperature and high speed and to work in situ in the exhaust manifold of combustion engines at temperatures as high as 600 o C, at which the deposited organic residuals on the detector can be oxidized. This assures a clear surface necessary for a real time optical measurement of the species concentration to be used for a closed loop control of the fuel injection process. The system was applied to the detection of CO and NO with concentration between 0% and 2% in a buffer of pure nitrogen gas, showing an increase in the measured photocurrent as a function of the above gases

  7. Measurement of nitrogen species NO{sub y} at the exhaust of an aircraft engine combustor

    Energy Technology Data Exchange (ETDEWEB)

    Ristori, A. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), Palaiseau (France); Baudoin, C. [Societe Nationale d`Etude et de Construction de Moteurs d`Aviation (SNECMA), Villaroche (France)

    1997-12-31

    A research programme named AEROTRACE was supported by the EC (CEC contract AERA-CT94-0003) in order to investigate trace species measurements at the exhaust of aero-engines. Within this project, NO{sub y}, NO, HNO{sub 3} and HONO were measured at the exhaust of aircraft engine combustors. Major species (NO{sub y},NO) were measured by using a chemiluminescence instrument. Minor species (HNO{sub 3},HONO) were measured by using filter packs. Two combustors were tested under various running conditions; the first one at ONERA (Task 2) and the second one at DRA (Task 5). Results show that EI{sub NOy} < 50 g/kg, EI{sub HNO3} < 0.2 g/kg and EI{sub HONO} < 0.55 g/kg. Regarding ratios, (HNO{sub 3})/(NO{sub y}) < 0.5%, (HONO)/(NO{sub y}) < 8%, (HONO)/(NO{sub 2}) {approx} 19.2%, and (HNO{sub 3})/(NO{sub 2}) {approx} 0.8% was found. (author) 9 refs.

  8. LOX/hydrocarbon rocket engine analytical design methodology development and validation. Volume 2: Appendices

    Science.gov (United States)

    Niiya, Karen E.; Walker, Richard E.; Pieper, Jerry L.; Nguyen, Thong V.

    1993-05-01

    This final report includes a discussion of the work accomplished during the period from Dec. 1988 through Nov. 1991. The objective of the program was to assemble existing performance and combustion stability models into a usable design methodology capable of designing and analyzing high-performance and stable LOX/hydrocarbon booster engines. The methodology was then used to design a validation engine. The capabilities and validity of the methodology were demonstrated using this engine in an extensive hot fire test program. The engine used LOX/RP-1 propellants and was tested over a range of mixture ratios, chamber pressures, and acoustic damping device configurations. This volume contains time domain and frequency domain stability plots which indicate the pressure perturbation amplitudes and frequencies from approximately 30 tests of a 50K thrust rocket engine using LOX/RP-1 propellants over a range of chamber pressures from 240 to 1750 psia with mixture ratios of from 1.2 to 7.5. The data is from test configurations which used both bitune and monotune acoustic cavities and from tests with no acoustic cavities. The engine had a length of 14 inches and a contraction ratio of 2.0 using a 7.68 inch diameter injector. The data was taken from both stable and unstable tests. All combustion instabilities were spontaneous in the first tangential mode. Although stability bombs were used and generated overpressures of approximately 20 percent, no tests were driven unstable by the bombs. The stability instrumentation included six high-frequency Kistler transducers in the combustion chamber, a high-frequency Kistler transducer in each propellant manifold, and tri-axial accelerometers. Performance data is presented, both characteristic velocity efficiencies and energy release efficiencies, for those tests of sufficient duration to record steady state values.

  9. Kinetic---a system code for analyzing nuclear thermal propulsion rocket engine transients

    International Nuclear Information System (INIS)

    Schmidt, E.; Lazareth, O.; Ludewig, H.

    1993-01-01

    A system code suitable for analyzing Nuclear Thermal Propulsion (NTP) rocket engines is described in this paper. The code consists of a point reactor model and nodes to describe the fluid dynamics and heat transfer mechanism. Feedback from the fuel, coolant, moderator and reflector are allowed for, and the control of the reactor is by motion of controls element (drums or rods). The worth of the control element and feedback coefficients are predetermined. Separate models for the turbo-pump assembly (TPA) and nozzle are also included. The model to be described in this paper is specific for the Particle Bed Reactor (PBR). An illustrative problem is solved. This problem consists of a PBR operating in a blowdown mode

  10. Kinetic—a system code for analyzing nuclear thermal propulsion rocket engine transients

    Science.gov (United States)

    Schmidt, Eldon; Lazareth, Otto; Ludewig, Hans

    1993-01-01

    A system code suitable for analyzing Nuclear Thermal Propulsion (NTP) rocket engines is described in this paper. The code consists of a point reactor model and nodes to describe the fluid dynamics and heat transfer mechanism. Feedback from the fuel, coolant, moderator and reflector are allowed for, and the control of the reactor is by motion of controls element (drums or rods). The worth of the control element and feedback coefficients are predetermined. Separate models for the turbo-pump assembly (TPA) and nozzle are also included. The model to be described in this paper is specific for the Particle Bed Reactor (PBR). An illustrative problem is solved. This problem consists of a PBR operating in a blowdown mode.

  11. KINETIC: A system code for analyzing Nuclear thermal propulsion rocket engine transients

    Science.gov (United States)

    Schmidt, E.; Lazareth, O.; Ludewig, H.

    1993-07-01

    A system code suitable for analyzing Nuclear Thermal Propulsion (NTP) rocket engines is described in this paper. The code consists of a point reactor model and nodes to describe the fluid dynamics and heat transfer mechanism. Feedback from the fuel coolant, moderator and reflector are allowed for, and the control of the reactor is by motion of control elements (drums or rods). The worth of the control clement and feedback coefficients are predetermined. Separate models for the turbo-pump assembly (TPA) and nozzle are also included. The model to be described in this paper is specific for the Particle Bed Reactor (PBR). An illustrative problem is solved. This problem consists of a PBR operating in a blowdown mode.

  12. Status on Technology Development of Optic Fiber-Coupled Laser Ignition System for Rocket Engine Applications

    Science.gov (United States)

    Trinh, Huu P.; Early, Jim; Osborne, Robin; Thomas, Matthew; Bossard, John

    2003-01-01

    To pursue technology developments for future launch vehicles, NASA/Marshall Space Flight Center (MSFC) is examining vortex chamber concepts for liquid rocket engine applications. Past studies indicated that the vortex chamber schemes potentially have a number of advantages over conventional chamber methods. Due to the nature of the vortex flow, relatively cooler propellant streams tend to flow along the chamber wall. Hence, the thruster chamber can be operated without the need of any cooling techniques. This vortex flow also creates strong turbulence, which promotes the propellant mixing process. Consequently, the subject chamber concept: not only offer system simplicity, but also enhance the combustion performance. Test results have shown that chamber performance is markedly high even at a low chamber length-to-diameter ratio. This incentive can be translated to a convenience in the thrust chamber packaging.

  13. Exhaust emissions reduction from diesel engine using combined Annona-Eucalyptus oil blends and antioxidant additive

    Science.gov (United States)

    Senthil, R.; Silambarasan, R.; Pranesh, G.

    2017-03-01

    The limited resources, rising petroleum prices and depletion of fossil fuel have now become a matter of great concern. Hence, there is an urgent need for researchers to find some alternate fuels which are capable of substituting partly or wholly the higher demanded conventional diesel fuel. Lot of research work has been conducted on diesel engine using biodiesel and its blends with diesel as an alternate fuel. Very few works have been done with combination of biodiesel-Eucalypts oil without neat diesel and this leads to lots of scope in this area. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using eucalyptus oil-biodiesel as fuel. The presence of eucalyptus oil in the blend reduces the viscosity and improves the volatility of the blends. The methyl ester of Annona oil is blended with eucalypts oil in 10, 20, 30, 40 and 50 %. The performance and emission characteristics are evaluated by operating the engine at different loads. The performance characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust gas temperature are evaluated. The emission constituents measured are Carbon monoxide (CO), unburned hydrocarbons (HC), Oxides of nitrogen (NOx) and Smoke. It is found that A50-Eu50 (50 Annona + 50 % Eucalyptus oil) blend showed better performance and reduction in exhaust emissions. But, it showed a very marginal increase in NOx emission when compared to that of diesel. Therefore, in order to reduce the NOx emission, antioxidant additive (A-tocopherol acetate) is mixed with Annona-Eucalyptus oil blends in various proportions by which NOx emission is reduced. Hence, A50-Eu50 blend can be used as an alternate fuel for diesel engine without any modifications.

  14. Primary Emission and the Potential of Secondary Aerosol Formation from Chinese Gasoline Engine Exhaust

    Science.gov (United States)

    Hu, Min; Peng, Jianfei; Qin, Yanhong; Du, Zhuofei; Li, Mengjin; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Lu, Sihua; Wu, Yusheng; Zeng, Limin; Guo, Song; Shao, Min; Wang, Yinhui; Shuai, Shijin

    2017-04-01

    Along with the urbanization and economic growth, vehicle population in China reached 269 million, ranked the second in the world in 2015. Gasoline vehicle is identified to be the main source for urban PM2.5 in China, accounting for 15%-31%. In this study the impact of fuel components on PM2.5 and volatile organic compounds (VOCs) emissions from a gasoline port fuel injection (PFI) engine and a gasoline direct injection (GDI) engine are discussed. Results show that, higher proportion of aromatics, alkenes or sulfur in gasoline fuel will lead to higher PM emissions. The PM from the PFI engine mainly consists of OC and a small amount of EC and inorganic ions, while the PM discharge from the GDI engine mainly consists of EC, OM and a small amount of inorganic ions. Since the GDI engines can reduce fuel consumption and CO2 emissions, and it would become more and more popular in the near future. The characteristics of POM component, emission factors and source profile were investigated from GDI engine, particularly focused on the effect of engine speed, load and the catalyst, which will be very much helpful for source identification as source indicators. Chamber experiments were conducted to quantify the potential of secondary aerosol formation from exhaust of a PFI gasoline engine and China V gasoline fuel. During 4-5 h simulation, equivalent to10 days of atmospheric photo-oxidation in Beijing, the extreme SOA production was 426 ± 85 mg/kg fuel, with high precursors and OH exposure. 14% of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatility organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reduction of emissions of aerosol precursor gases from vehicles is essential to mediate pollution in China.

  15. Fuzzy/Neural Software Estimates Costs of Rocket-Engine Tests

    Science.gov (United States)

    Douglas, Freddie; Bourgeois, Edit Kaminsky

    2005-01-01

    The Highly Accurate Cost Estimating Model (HACEM) is a software system for estimating the costs of testing rocket engines and components at Stennis Space Center. HACEM is built on a foundation of adaptive-network-based fuzzy inference systems (ANFIS) a hybrid software concept that combines the adaptive capabilities of neural networks with the ease of development and additional benefits of fuzzy-logic-based systems. In ANFIS, fuzzy inference systems are trained by use of neural networks. HACEM includes selectable subsystems that utilize various numbers and types of inputs, various numbers of fuzzy membership functions, and various input-preprocessing techniques. The inputs to HACEM are parameters of specific tests or series of tests. These parameters include test type (component or engine test), number and duration of tests, and thrust level(s) (in the case of engine tests). The ANFIS in HACEM are trained by use of sets of these parameters, along with costs of past tests. Thereafter, the user feeds HACEM a simple input text file that contains the parameters of a planned test or series of tests, the user selects the desired HACEM subsystem, and the subsystem processes the parameters into an estimate of cost(s).

  16. Coil-On-Plug Ignition for LOX/Methane Liquid Rocket Engines in Thermal Vacuum Environments

    Science.gov (United States)

    Melcher, John C.; Atwell, Matthew J.; Morehead, Robert L.; Hurlbert, Eric A.; Bugarin, Luz; Chaidez, Mariana

    2017-01-01

    A coil-on-plug ignition system has been developed and tested for Liquid Oxygen (LOX) / liquid methane rocket engines operating in thermal vacuum conditions. The igniters were developed and tested as part of the Integrated Cryogenic Propulsion Test Article (ICPTA), previously tested as part of the Project Morpheus test vehicle. The ICPTA uses an integrated, pressure-fed, cryogenic LOX/methane propulsion system including a reaction control system (RCS) and a main engine. The ICPTA was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. In order to successfully demonstrate ignition reliability in the vacuum conditions and eliminate corona discharge issues, a coil-on-plug ignition system has been developed. The ICPTA uses spark-plug ignition for both the main engine igniter and the RCS. The coil-on-plug configuration eliminates the conventional high-voltage spark plug cable by combining the coil and the spark-plug into a single component. Prior to ICPTA testing at Plum Brook, component-level reaction control engine (RCE) and main engine igniter testing was conducted at NASA Johnson Space Center (JSC), which demonstrated successful hot-fire ignition using the coil-on-plug from sea-level ambient conditions down to 10(exp.-2) torr. Integrated vehicle hot-fire testing at JSC demonstrated electrical and command/data system performance. Lastly, Plum Brook testing demonstrated successful ignitions at simulated altitude conditions at 30 torr and cold thermal-vacuum conditions at 6 torr. The test campaign successfully proved that coil-on-plug technology will enable integrated LOX/methane propulsion systems in future spacecraft.

  17. Evaluation of SI engine exhaust gas emissions upstream and downstream of the catalytic converter

    International Nuclear Information System (INIS)

    Silva, C.M.; Costa, M.; Farias, T.L.; Santos, H.

    2006-01-01

    The conversion efficiency of a catalytic converter, mounted on a vehicle equipped with a 2.8 l spark ignition engine, was evaluated under steady state operating conditions. The inlet and outlet chemical species concentration, temperature and air fuel ratio (A/F) were measured as a function of the brake mean effective pressure (BMEP) and engine speed (rpm). Oil temperature, coolant temperature, brake power and spark advance were also monitored. In parallel, a mathematical model for the catalytic converter has been developed. The main inputs of the model are the temperature, flow rate, chemical species mass flow and local A/F ratio as measured at the catalyst inlet section. The main conclusions are: (i) the exhaust gas and substrate wall temperatures at the catalyst outlet increase with BMEP and rpm; (ii) the HC conversion efficiency increases with the value of BMEP up to a maximum beyond which it decreases; (iii) the CO conversion efficiencies typically increase with BMEP; (iv) the NO x conversion efficiency remains nearly constant regardless of BMEP and rpm; (v) except for idle, the NO x conversion efficiency is typically the highest, followed in turn by the CO and HC conversion efficiencies; (vi) conversion efficiencies are lower for idle conditions, which can be a problem under traffic conditions where idle is a common situation; (vii) regardless of rpm and load, for the same flow rate the conversion efficiency is about the same; (viii) the model predictions slightly over estimate the exhaust gas temperature data at the catalyst outlet section with the observed differences decreasing with BMEP and engine speed; (ix) in general, the model predictions of the conversion efficiencies are satisfactory

  18. Numerical simulations on increasing turbojet engines exhaust mixture ratio using fluidic chevrons

    Directory of Open Access Journals (Sweden)

    Adrian GRUZEA

    2017-06-01

    Full Text Available This paper refers to some aspects regarding the terms “chevron” and “fluidic chevron” and to the process of increasing the jet engines exhaust mixing rate towards achieving noise reduction. One of the noise reduction methods consists in covering the high velocity main flow with a secondary one, having a much lower velocity, similar to the turbofan engines. The fluidic chevrons try to accomplish these requirements, being used just in particular moments of the flight. This study will be based on numerical simulations carried using the commercial software ANSYS. The geometry used will the based on the micro jet engine JetCat P80, equipping the turbines laboratory from the Faculty of Aerospace Engineering. A research based on the measured geometric, gasodynamic and cinematic parameters will be carried varying the mass flow and keeping the immersion angle constant. As a result of these simulations we’ll observe the influence of the mentioned parameters on the jet’s flow field.

  19. Combustion Performance and Exhaust Emission of DI Diesel Engine Using Various Sources of Waste Cooking Oil

    Science.gov (United States)

    Afiq, Mohd; Azuhairi, Mohd; Jazair, Wira

    2010-06-01

    In Malaysia, more than 200-tone of cooking oil are used by domestic users everyday. After frying process, about a quarter of these cooking oil was remained and drained into sewage system. This will pollutes waterways and affects the ecosystem. The use of waste cooking oil (WCO) for producing bio-diesel was considered in economical factor which current production cost of bio-diesel production is higher in Malaysia due to higher price of palm oil. Thus, the aim of this study is to investigate the most suitable source of WCO to become a main source of bio-diesel for bio-diesel production in this country. To perform this research, three type of WCO were obtained from house's kitchen, cafeteria and mamak's restaurant. In this study, prospect of these bio-diesel source was evaluated based on its combustion performance and exhaust emissions operated in diesel engine in the form of waste cooking oil methyl ester (WCOME) and have been compared with pure diesel fuel. A 0.6 liter, single-cylinder, air-cooled direct injection diesel engine was used to perform this experiment. Experiment was done at variable engine loads and constant engine speed. As the result, among three stated WCOMEs, the one collected from house's kitchen gives the best performance in term of brake specific fuel consumption (bsfc) and brake power (BP) with lowest soot emission.

  20. Analysis of benefits of using internal exhaust gas recirculation in biogas-fueled HCCI engines

    International Nuclear Information System (INIS)

    Kozarac, Darko; Vuilleumier, David; Saxena, Samveg; Dibble, Robert W.

    2014-01-01

    Highlights: • The influence of EGR on combustion of biogas fueled HCCI was investigated. • The aim was to reduce intake temperature requirement by internal EGR. • Combustion products caused the delay of combustion in similar conditions. • Internal EGR enabled by negative valve overlap increased cylinder temperature. • This increase was not enough to significantly reduce the intake temperature. - Abstract: This paper describes a numerical study that analyzed the influence of combustion products (CP) concentration on the combustion characteristics (combustion timing and combustion duration) of a biogas fueled homogeneous charge compression ignition (HCCI) engine and the possibility of reducing the high intake temperature requirement necessary for igniting biogas in a HCCI engine by using internal exhaust gas recirculation (EGR) enabled by negative valve overlap (NVO). An engine model created in AVL Boost, and validated against experimental engine data, was used in this study. The results show, somewhat counter-intuitively, that when CP concentrations are increased the required intake temperature for maintaining the same combustion timing must be increased. When greater NVO is used to increase the in-cylinder CP concentration, the in-cylinder temperature does increase, but the chemical dilution influence of CP almost entirely counteracts this thermal effect. Additionally, it has been observed that with larger fractions of CP some instability of combustion in the calculation was obtained which indicates that the increase of internal EGR might produce some combustion instability

  1. The effect of ethanol-gasoline blends on performance and exhaust emissions of a spark ignition engine through exergy analysis

    International Nuclear Information System (INIS)

    Doğan, Battal; Erol, Derviş; Yaman, Hayri; Kodanli, Evren

    2017-01-01

    Highlights: • Examining the performance of ethanol-gasoline blend. • Evaluation of the exhaust emissions. • Energy and exergy analysis. • Calculation of irreversibility from cooling system and the exhaust resulting. - Abstract: Ethanol which is considered as an environmentally cleaner alternative to fossil fuels is used on its own or blended with other fuels in different ratios. In this study, ethanol which has high octane rating, low exhaust emission, and which is easily obtained from agricultural products has been used in fuels prepared by blending it with gasoline in various ratios (E0, E10, E20, and E30). Ethanol-gasoline blends have been used in a four-cylinder four-stroke spark ignition engine for performance and emission analysis under full load. In the experimental studies, engine torque, fuel and cooling water flow rates, and exhaust and engine surface temperature have been measured. Engine energy distribution, irreversible processes in the cooling system and the exhaust, and the exergy distribution have been calculated using the experimental data and the formulas for the first and second laws of thermodynamics. Experiments and theoretical calculations showed that ethanol added fuels show reduction in carbon monoxide (CO), carbon dioxide (CO_2) and nitrogen oxide (NO_X) emissions without significant loss of power compared to gasoline. But it was measured that the reduction of the temperature inside the cylinder increases the hydrocarbon (HC) emission.

  2. Effects of ethanol-diesel fuel blends on the performance and exhaust emissions of heavy duty DI diesel engine

    International Nuclear Information System (INIS)

    Rakopoulos, D.C.; Rakopoulos, C.D.; Kakaras, E.C.; Giakoumis, E.G.

    2008-01-01

    An experimental investigation is conducted to evaluate the effects of using blends of ethanol with conventional diesel fuel, with 5% and 10% (by vol.) ethanol, on the performance and exhaust emissions of a fully instrumented, six-cylinder, turbocharged and after-cooled, heavy duty, direct injection (DI), Mercedes-Benz engine, installed at the authors' laboratory, which is used to power the mini-bus diesel engines of the Athens Urban Transport Organization sub-fleet with a view to using bio-ethanol produced from Greek feedstock. The tests are conducted using each of the above fuel blends, with the engine working at two speeds and three loads. Fuel consumption, exhaust smokiness and exhaust regulated gas emissions such as nitrogen oxides, carbon monoxide and total unburned hydrocarbons are measured. The differences in the measured performance and exhaust emissions of the two ethanol-diesel fuel blends from the baseline operation of the engine, i.e. when working with neat diesel fuel, are determined and compared. Theoretical aspects of diesel engine combustion combined with the widely differing physical and chemical properties of the ethanol against those for the diesel fuel, are used to aid the correct interpretation of the observed engine behavior

  3. Effects of injection timing on the engine performance and exhaust emissions of a dual-fuel diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Sayin, Cenk [Department of Mechanical Education, Marmara University, 34722 Istanbul (Turkey); Canakci, Mustafa [Department of Mechanical Education, Kocaeli University, 41380 Izmit (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Izmit (Turkey)

    2009-01-15

    In this study, influence of injection timing on the engine performance and exhaust emissions of a naturally aspirated, single cylinder diesel engine has been experimentally investigated when using ethanol blended diesel fuel from 0% to 15% with an increment of 5%. The engine load was selected as 15 and 30 Nm. The tests were conducted at five different injection timings (21 , 24 , 27 , 30 and 33 CA BTDC) by changing the thickness of advance shim. The experimental test results showed that BSFC and emissions of NO{sub x} and CO{sub 2} increased as BTE and emissions of CO and HC decreased with increasing amount of ethanol in the fuel mixture. When compared to the results of original injection timing (27 CA BTDC), NO{sub x} and CO{sub 2} emissions increased, and unburned HC and CO emissions decreased for the retarded injection timings (21 and 24 CA BTDC) at the all test conditions. On the other side, with the advanced injection timings (30 and 33 CA BTDC), decreasing HC and CO emissions diminished, and NO{sub x} and CO{sub 2} emissions boosted. In terms of BSFC and BTE, retarded and advanced injection timings compared to the original injection timing in the all fuel blends gave negative results for all engine speeds and loads. (author)

  4. Effects of injection timing on the engine performance and exhaust emissions of a dual-fuel diesel engine

    International Nuclear Information System (INIS)

    Sayin, Cenk; Canakci, Mustafa

    2009-01-01

    In this study, influence of injection timing on the engine performance and exhaust emissions of a naturally aspirated, single cylinder diesel engine has been experimentally investigated when using ethanol blended diesel fuel from 0% to 15% with an increment of 5%. The engine load was selected as 15 and 30 Nm. The tests were conducted at five different injection timings (21 deg., 24 deg., 27 deg., 30 deg. and 33 deg. CA BTDC) by changing the thickness of advance shim. The experimental test results showed that BSFC and emissions of NO x and CO 2 increased as BTE and emissions of CO and HC decreased with increasing amount of ethanol in the fuel mixture. When compared to the results of original injection timing (27 deg. CA BTDC), NO x and CO 2 emissions increased, and unburned HC and CO emissions decreased for the retarded injection timings (21 deg. and 24 deg. CA BTDC) at the all test conditions. On the other side, with the advanced injection timings (30 deg. and 33 deg. CA BTDC), decreasing HC and CO emissions diminished, and NO x and CO 2 emissions boosted. In terms of BSFC and BTE, retarded and advanced injection timings compared to the original injection timing in the all fuel blends gave negative results for all engine speeds and loads

  5. Fuel characterisation, engine performance, combustion and exhaust emissions with a new renewable Licella biofuel

    International Nuclear Information System (INIS)

    Nabi, Md Nurun; Rahman, Md Mostafizur; Islam, Muhammad Aminul; Hossain, Farhad M.; Brooks, Peter; Rowlands, William N.; Tulloch, John; Ristovski, Zoran D.; Brown, Richard J.

    2015-01-01

    Highlights: • A new biofuel produced by hydrothermal liquefaction is investigated. • Licella biofuel blends showed no significant changes in engine performance. • Licella blends showed higher THC and NO emissions. • PM and PN emissions were observed to be lower for all Licella blends. • Hydrothermal liquefaction Licella biofuel is suitable for use in diesel engine. - Abstract: The current study investigates the opportunity of using Licella biofuel as a partly renewable fuel provided by Licella P/L. Hereafter this fuel will be referred to as Licella biofuel. The renewable component of the Licella biofuel was made from the hydrothermal conversion of Australian pinus radiata wood flour using Licella’s proprietary Cat-HTR™ technology. The diesel-soluble component of the hydrothermal product was extracted into road diesel to give a blended fuel containing approximately 30% renewable material with the balance from diesel. This was further blended with a regular diesel fuel (designated R0) to give fuels for testing containing 5%, 10% and 20% renewable fuel (designated R5, R10 and R20). Some of the key fuel properties were measured for R30 and compared with those of regular diesel fuel. The engine experiment was conducted on a four-cylinder turbocharged common rail direct injection diesel engine. All experiments were performed with a constant speed and five different engine loads. Exhaust emissions including particulate matter (PM) mass and numbers, nitric oxide (NO), total unburnt hydrocarbon (THC), carbon dioxide (CO 2 ) and performance parameters including brake power (BP), indicated power (IP), brake mean effective pressure (BMEP), indicated mean effective pressure (IMEP), mechanical efficiency (ME), brake thermal efficiency (BTE) and brake specific energy consumption (BSEC) were investigated for all four blends (R0, R5, R10 and R20). Among other engine parameters, in-cylinder pressure, heat release rate (HRR) and pressure (P) versus volume (V) diagrams

  6. Nuclear rockets

    International Nuclear Information System (INIS)

    Sarram, M.

    1972-01-01

    Nuclear energy has found many applications in space projects. This article deals with these applications. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear energy for propulsion purposes in space flight. The main objective is to develop a 75000 pound thrust flight engine call NERVA by heating liquid hydrogen, in a nuclear reactor, from 420F to 4000 0 F. The paper describes in detail the salient features of the NERVA rocket as well as its comparison with the conventional chemical rockets. It is shown that a nuclear rocket using liquid hydrogen as medium is at least 85% more efficient as compared with the chemical rockets such as those used for the APOLLO moon flight

  7. Nuclear rockets

    Energy Technology Data Exchange (ETDEWEB)

    Sarram, M [Teheran Univ. (Iran). Inst. of Nuclear Science and Technology

    1972-02-01

    Nuclear energy has found many applications in space projects. This article deals with these applications. The first application is the use of nuclear energy for the production of electricity in space and the second main application is the use of nuclear energy for propulsion purposes in space flight. The main objective is to develop a 75000 pound thrust flight engine called NERVA by heating liquid hydrogen in a nuclear reactor. The paper describes in detail the salient features of the NERVA rocket as well as its comparison with the conventional chemical rockets. It is shown that a nuclear rocket using liquid hydrogen as medium is at least 85% more efficient as compared with the chemical rockets such as those used for the APOLLO moon flight.

  8. Impact of an Exhaust Throat on Semi-Idealized Rotating Detonation Engine Performance

    Science.gov (United States)

    Paxson, Daniel E.

    2016-01-01

    A computational fluid dynamic (CFD) model of a rotating detonation engine (RDE) is used to examine the impact of an exhaust throat (i.e., a constriction) on performance. The model simulates an RDE which is premixed, adiabatic, inviscid, and which contains an inlet valve that prevents backflow from the high pressure region directly behind the rotating detonation. Performance is assessed in terms of ideal net specific impulse which is computed on the assumption of lossless expansion of the working fluid to the ambient pressure through a notional diverging nozzle section downstream of the throat. Such a semi-idealized analysis, while not real-world, allows the effect of the throat to be examined in isolation from, rather than coupled to (as it actually is) various loss mechanisms. For the single Mach 1.4 flight condition considered, it is found that the addition of a throat can yield a 9.4 percent increase in specific impulse. However, it is also found that when the exit throat restriction gets too small, an unstable type of operation ensues which eventually leads to the detonation failing. This behavior is found to be somewhat mitigated by the addition of an RDE inlet restriction across which there is an aerodynamic loss. Remarkably, this loss is overcome by the benefits of the further exhaust restrictions allowed. The end result is a configuration with a 10.3 percent improvement in ideal net specific thrust.

  9. Passive Sampling and Analysis of Naphthalene in Internal Combustion Engine Exhaust with Retracted SPME Device and GC-MS

    Directory of Open Access Journals (Sweden)

    Nassiba Baimatova

    2017-07-01

    Full Text Available Exhaust gases from internal combustion engines are the main source of urban air pollution. Quantification of Polycyclic aromatic hydrocarbons (PAHs in the exhaust gases is needed for emissions monitoring, enforcement, development, and testing of control technologies. The objective was to develop quantification of gaseous naphthalene in diesel engine exhaust based on diffusion-controlled extraction onto a retracted solid-phase microextraction (SPME fiber coating and analysis on gas chromatography-mass spectrometry (GC-MS. Extraction of naphthalene with retracted fibers followed Fick’s law of diffusion. Extracted mass of naphthalene was proportional to Cg, t, Dg, T and inversely proportional to Z. Method detection limit (p = 0.95 was 11.5 ppb (0.06 mg·m−3 at t = 9 h, Z = 10 mm and T = 40 °C, respectively. It was found that the % mass extracted of naphthalene by SPME needle assembly depended on the type of fiber. Storage time at different temperatures did not affect analyte losses extracted by polydimethylsiloxane (PDMS 100 µm fiber. The developed method was tested on exhaust gases from idling pickup truck and tractor, and compared side-by-side with a direct injection of sampled exhaust gas method. Time-weighted average (TWA concentrations of naphthalene in exhaust gases from idling pickup truck and a tractor ranged from 0.08 to 0.3 mg·m−3 (15.3–53.7 ppb.

  10. Genetic algorithm to optimize the design of main combustor and gas generator in liquid rocket engines

    Science.gov (United States)

    Son, Min; Ko, Sangho; Koo, Jaye

    2014-06-01

    A genetic algorithm was used to develop optimal design methods for the regenerative cooled combustor and fuel-rich gas generator of a liquid rocket engine. For the combustor design, a chemical equilibrium analysis was applied, and the profile was calculated using Rao's method. One-dimensional heat transfer was assumed along the profile, and cooling channels were designed. For the gas-generator design, non-equilibrium properties were derived from a counterflow analysis, and a vaporization model for the fuel droplet was adopted to calculate residence time. Finally, a genetic algorithm was adopted to optimize the designs. The combustor and gas generator were optimally designed for 30-tonf, 75-tonf, and 150-tonf engines. The optimized combustors demonstrated superior design characteristics when compared with previous non-optimized results. Wall temperatures at the nozzle throat were optimized to satisfy the requirement of 800 K, and specific impulses were maximized. In addition, the target turbine power and a burned-gas temperature of 1000 K were obtained from the optimized gas-generator design.

  11. Derating design for optimizing reliability and cost with an application to liquid rocket engines

    International Nuclear Information System (INIS)

    Kim, Kyungmee O.; Roh, Taeseong; Lee, Jae-Woo; Zuo, Ming J.

    2016-01-01

    Derating is the operation of an item at a stress that is lower than its rated design value. Previous research has indicated that reliability can be increased from operational derating. In order to derate an item in field operation, however, an engineer must rate the design of the item at a stress level higher than the operational stress level, which increases the item's nominal failure rate and development costs. At present, there is no model available to quantify the cost and reliability that considers the design uprating as well as the operational derating. In this paper, we establish the reliability expression in terms of the derating level assuming that the nominal failure rate is constant with time for a fixed rated design value. The total development cost is expressed in terms of the rated design value and the number of tests necessary to demonstrate the reliability requirement. The properties of the optimal derating level are explained for maximizing the reliability or for minimizing the cost. As an example, the proposed model is applied to the design of liquid rocket engines. - Highlights: • Modeled the effect of derating design on the reliability and the development cost. • Discovered that derating design may reduce the cost of reliability demonstration test. • Optimized the derating design parameter for reliability maximization or cost minimization.

  12. Fast reconstruction of an unmanned engineering vehicle and its application to carrying rocket

    Directory of Open Access Journals (Sweden)

    Jun Qian

    2014-04-01

    Full Text Available Engineering vehicle is widely used as a huge moving platform for transporting heavy goods. However, traditional human operations have a great influence on the steady movement of the vehicle. In this Letter, a fast reconstruction process of an unmanned engineering vehicle is carried out. By adding a higher-level controller and two two-dimensional laser scanners on the moving platform, the vehicle could perceive the surrounding environment and locate its pose according to extended Kalman filter. Then, a closed-loop control system is formed by communicating with the on-board lower-level controller. To verify the performance of automatic control system, the unmanned vehicle is automatically navigated when carrying a rocket towards a launcher in a launch site. The experimental results show that the vehicle could align with the launcher smoothly and safely within a small lateral deviation of 1 cm. This fast reconstruction presents an efficient way of rebuilding low-cost unmanned special vehicles and other automatic moving platforms.

  13. Integrated System Health Management: Pilot Operational Implementation in a Rocket Engine Test Stand

    Science.gov (United States)

    Figueroa, Fernando; Schmalzel, John L.; Morris, Jonathan A.; Turowski, Mark P.; Franzl, Richard

    2010-01-01

    This paper describes a credible implementation of integrated system health management (ISHM) capability, as a pilot operational system. Important core elements that make possible fielding and evolution of ISHM capability have been validated in a rocket engine test stand, encompassing all phases of operation: stand-by, pre-test, test, and post-test. The core elements include an architecture (hardware/software) for ISHM, gateways for streaming real-time data from the data acquisition system into the ISHM system, automated configuration management employing transducer electronic data sheets (TEDS?s) adhering to the IEEE 1451.4 Standard for Smart Sensors and Actuators, broadcasting and capture of sensor measurements and health information adhering to the IEEE 1451.1 Standard for Smart Sensors and Actuators, user interfaces for management of redlines/bluelines, and establishment of a health assessment database system (HADS) and browser for extensive post-test analysis. The ISHM system was installed in the Test Control Room, where test operators were exposed to the capability. All functionalities of the pilot implementation were validated during testing and in post-test data streaming through the ISHM system. The implementation enabled significant improvements in awareness about the status of the test stand, and events and their causes/consequences. The architecture and software elements embody a systems engineering, knowledge-based approach; in conjunction with object-oriented environments. These qualities are permitting systematic augmentation of the capability and scaling to encompass other subsystems.

  14. Engineering studies of tritium recovery from CTR blankets and plasma exhaust

    International Nuclear Information System (INIS)

    Watson, J.S.

    1975-01-01

    Engineering studies on tritium handling problems in fusion reactors have included conceptual and experimental studies of techniques for recovery of tritium bred in the reactor blanket and conceptual designs for recovery and processing of tritium from plasma exhausts. The process requirements and promising techniques for the blanket system depend upon the materials used for the blanket, coolant, and structure and on the operating temperatures. Process requirements are likely to be set in some systems by allowable loss rates to the steam system or by inventory considerations. Conceptual studies have also been made for tritium handling equipment for fueling, recovery, and processing in plasma recycle systems of fusion reactors, and a specific design has been prepared for ''near-term'' Tokamak experiments. (auth)

  15. Investigation of Nitro-Organic Compounds in Diesel Engine Exhaust: Final Report, February 2007 - April 2008

    Energy Technology Data Exchange (ETDEWEB)

    Dane, J.; Voorhees, K. J.

    2010-06-01

    The National Renewable Energy Laboratory upgraded its ReFUEL engine and vehicle testing facility to speciate unregulated gas-phase emissions. To complement this capability, the laboratory contracted with the Colorado School of Mines (CSM) to study the effects of soy biodiesel fuel and a diesel particle filter (DPF) on emissions of polycyclic aromatic hydrocarbons (PAH) and nitro-polycyclic aromatic hydrocarbons (NPAH). CSM developed procedures to sample diesel particulate matter (PM) emissions from raw and diluted exhaust, with and without a DPF. They also developed improved procedures for extracting PAH and NPAH from the PM and quantifying them with a gas chromatograph-electron monochromator mass spectrometer. The study found the DPF generally reduced PAH emissions by 1 to 3 orders of magnitude. PAH conversion was lowest for B100, suggesting that PAHs were forming in the DPF. Orders of magnitude reductions were also found for NPAH emissions exiting the DPF.

  16. Cycle-by-cycle exhaust temperature monitoring for detection of misfiring and combustion instability in reciprocating natural gas engines

    Energy Technology Data Exchange (ETDEWEB)

    Gardiner, D.P. [Nexum Research Corp., Kingston, ON (Canada); Bardon, M.F. [Royal Military Coll. of Canada, Kingston, ON (Canada). Dept. of Mechanical Engineering

    2007-07-01

    The effectiveness of a cycle-by-cycle exhaust temperature monitoring system on engines operating at or near their fully rate load capacity was examined. Tests were conducted on stationary industrial natural gas engines. The study evaluated the monitoring system's ability to detect isolated single misfires, as well as combustion instability during misfire-free operations when the air/fuel ratio of the engine was adjusted to progressively lower settings. The combustion instability level of the engines was quantified by determining the relative variability of the groups of consecutive cycles. The coefficient of variation of indicated mean effective pressure (COV of IMEP) was used to examine cyclic variability. A combustion instability index was used to quantify cyclic variability with cycle-by-cycle exhaust temperature monitoring. Two engines were tested, notably a Cummins QSK 19G turbocharged natural gas engine; and a Waukesha VHP L5790G industrial natural gas engine. The tests demonstrated that cycle-by-cycle exhaust temperature monitoring system was capable of detecting misfiring and combustion instabilities in natural gas engines. 6 refs., 9 figs.

  17. Experimental study on engine gas-path component fault monitoring using exhaust gas electrostatic signal

    International Nuclear Information System (INIS)

    Sun, Jianzhong; Zuo, Hongfu; Liu, Pengpeng; Wen, Zhenhua

    2013-01-01

    This paper presents the recent development in engine gas-path components health monitoring using electrostatic sensors in combination with signal-processing techniques. Two ground-based engine electrostatic monitoring experiments are reported and the exhaust gas electrostatic monitoring signal-based fault-detection method is proposed. It is found that the water washing, oil leakage and combustor linear cracking result in an increase in the activity level of the electrostatic monitoring signal, which can be detected by the electrostatic monitoring system. For on-line health monitoring of the gas-path components, a baseline model-based fault-detection method is proposed and the multivariate state estimation technique is used to establish the baseline model for the electrostatic monitoring signal. The method is applied to a data set from a turbo-shaft engine electrostatic monitoring experiment. The results of the case study show that the system with the developed method is capable of detecting the gas-path component fault in an on-line fashion. (paper)

  18. Influence of injection timing on the exhaust emissions of a dual-fuel CI engine

    Energy Technology Data Exchange (ETDEWEB)

    Sayin, Cenk [Department of Mechanical Education, Marmara University, 34722 Istanbul (Turkey); Uslu, Kadir [Department of Automotive Education, Fatih Vocational High School, 54100 Sakarya (Turkey); Canakci, Mustafa [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Kocaeli (Turkey)

    2008-06-15

    Environmental concerns and limited amount of petroleum fuels have caused interests in the development of alternative fuels for internal combustion (IC) engines. As an alternative, biodegradable, and renewable fuel, ethanol is receiving increasing attention. Therefore, in this study, influence of injection timing on the exhaust emission of a single cylinder, four stroke, direct injection, naturally aspirated diesel engine has been experimentally investigated using ethanol blended diesel fuel from 0% to 15% with an increment of 5%. The engine has an original injection timing 27 CA BTDC. The tests were performed at five different injection timings (21 , 24 , 27 , 30 , and 33 CA BTDC) by changing the thickness of advance shim. The experimental test results showed that NO{sub x} and CO{sub 2} emissions increased as CO and HC emissions decreased with increasing amount of ethanol in the fuel mixture. When compared to the results of original injection timing, at the retarded injection timings (21 and 24 CA BTDC), NO{sub x} and CO{sub 2} emissions increased, and unburned HC and CO emissions decreased for all test conditions. On the other hand, with the advanced injection timings (30 and 33 CA BTDC), HC and CO emissions diminished, and NO{sub x} and CO{sub 2} emissions boosted for all test conditions. (author)

  19. Marine diesel engines exhaust noise. Pt. VII: Calculation of the acoustical performance of diesel engine exhaust systems / Uitlaatgeluid van scheepsdieselmotoren. Dl. VII: Berekening van de akoestische eigenschappen van uitlaatsystemen van dieselmotoren

    NARCIS (Netherlands)

    Buiten, J.; Gerretsen, E.; Vellekoop, J.C.

    1974-01-01

    A method is given lor the calculation of the transfer damping of diesel engine exhaust systems. Also the complete computer program in FORTRAN IV, based on this calculation method is given. The method includes such system elements as chamber resonators, 1,5-pipes, absorbing siìencers and shunts to

  20. Improving the performance of LOX/kerosene upper stage rocket engines

    Directory of Open Access Journals (Sweden)

    IgorN. Nikischenko

    2017-09-01

    Full Text Available Improved liquid rocket engine cycles were proposed and analyzed via comparison with existing staged combustion and gas-generator cycles. The key features of the proposed cycles are regenerative cooling of thrust chamber by oxygen and subsequent use of this oxygen for driving one or two oxygen pumps. The fuel pump(s are driven in a conventional manner, for example, using a fuel-rich gas-generator cycle. Comparison with staged combustion cycle based on oxygen-rich pre-burner showed that one of the proposed semi-expander cycles has a specific impulse only on 0.4% lower while providing much lower oxygen temperature, more efficient tank pressurizing system and built-in roll control. This semi-expander cycle can be considered as a more reliable and cost-effective alternative of staged combustion cycle. Another semi-expander cycle can be considered as an improvement of gas-generator cycle. All proposed semi-expander cycles were developed as a derivative of thrust chamber regenerative cooling performed by oxygen. Analysis of existing oxygen/kerosene engines showed that replacing of kerosene regenerative cooling with oxygen allows a significant increase of achievable specific impulse, via optimization of mixture ratio. It is especially the case for upper stage engines. The increasing of propellants average density can be considered as an additional benefit of mixture ratio optimization. It was demonstrated that oxygen regenerative cooling of thrust chamber is a feasible and the most promising option for oxygen/kerosene engines. Combination of oxygen regenerative cooling and semi-expander cycles potentially allows creating the oxygen/kerosene propulsion systems with minimum specific impulse losses. It is important that such propulsion systems can be fully based on inherited and well-proven technical solutions. A hypothetic upper stage engine with thrust 19.6 kN was chosen as a prospective candidate for theoretical analysis of the proposed semi

  1. Acoustic streaming in simplified liquid rocket engines with transverse mode oscillations

    Science.gov (United States)

    Fischbach, Sean R.; Flandro, Gary A.; Majdalani, Joseph

    2010-06-01

    This study considers a simplified model of a liquid rocket engine in which uniform injection is imposed at the faceplate. The corresponding cylindrical chamber has a small length-to-diameter ratio with respect to solid and hybrid rockets. Given their low chamber aspect ratios, liquid thrust engines are known to experience severe tangential and radial oscillation modes more often than longitudinal ones. In order to model this behavior, tangential and radial waves are superimposed onto a basic mean-flow model that consists of a steady, uniform axial velocity throughout the chamber. Using perturbation tools, both potential and viscous flow equations are then linearized in the pressure wave amplitude and solved to the second order. The effects of the headwall Mach number are leveraged as well. While the potential flow analysis does not predict any acoustic streaming effects, the viscous solution carried out to the second order gives rise to steady secondary flow patterns near the headwall. These axisymmetric, steady contributions to the tangential and radial traveling waves are induced by the convective flow motion through interactions with inertial and viscous forces. We find that suppressing either the convective terms or viscosity at the headwall leads to spurious solutions that are free from streaming. In our problem, streaming is initiated at the headwall, within the boundary layer, and then extends throughout the chamber. We find that nonlinear streaming effects of tangential and radial waves act to alter the outer solution inside a cylinder with headwall injection. As a result of streaming, the radial wave velocities are intensified in one-half of the domain and reduced in the opposite half at any instant of time. Similarly, the tangential waves are either enhanced or weakened in two opposing sectors that are at 90° angle to the radial velocity counterparts. The second-order viscous solution that we obtain clearly displays both an oscillating and a steady flow

  2. Small rocket exhaust plume data

    Science.gov (United States)

    Chirivella, J. E.; Moynihan, P. I.; Simon, W.

    1972-01-01

    During recent cryodeposit tests with an 0.18-N thruster, the mass flux in the plume back field was measured for the first time for nitrogen, carbon dioxide, and a mixture of nitrogen, hydrogen, and ammonia at various inlet pressures. This mixture simulated gases that would be generated by a hydrazine plenum attitude propulsion system. The measurements furnish a base upon which to build a mathematical model of plume back flow that will be used in predicting the mass distribution in the boundary region of other plumes. The results are analyzed and compared with existing analytical predictions.

  3. Modeling and optimization of integrated exhaust gas recirculation and multi-stage waste heat recovery in marine engines

    DEFF Research Database (Denmark)

    Kyriakidis, Fotis; Sørensen, Kim; Singh, Shobhana

    2017-01-01

    Waste heat recovery combined with exhaust gas recirculation is a promising technology that can address both the issue of NOx (nitrogen oxides) reduction and fuel savings by including a pressurized boiler. In the present study, a theoretical optimization of the performance of two different...... configurations of steam Rankine cycles, with integrated exhaust gas recirculation for a marine diesel engine, is presented. The first configuration employs two pressure levels and the second is configured with three-pressure levels. The models are developed in MATLAB based on the typical data of a large two......-stroke marine diesel engine. A turbocharger model together with a blower, a pre-scrubber and a cooler for the exhaust gas recirculation line, are included. The steam turbine, depending on the configuration, is modeled as either a dual or triple pressure level turbine. The condensation and pre-heating process...

  4. An analytical study on the performance of the organic Rankine cycle for turbofan engine exhaust heat recovery

    Science.gov (United States)

    Saadon, S.; Abu Talib, A. R.

    2016-10-01

    Due to energy shortage and global warming, issues of energy saving have become more important. To increase the energy efficiency and reduce the fuel consumption, waste heat recovery is a significant method for energy saving. The organic Rankine cycle (ORC) has great potential to recover the waste heat from the core jet exhaust of a turbofan engine and use it to produce power. Preliminary study of the design concept and thermodynamic performance of this ORC system would assist researchers to predict the benefits of using the ORC system to extract the exhaust heat engine. In addition, a mathematical model of the heat transfer of this ORC system is studied and developed. The results show that with the increment of exhaust heat temperature, the mass flow rate of the working fluid, net power output and the system thermal efficiency will also increase. Consequently, total consumption of jet fuel could be significantly saved as well.

  5. Effect of buoyancy on fuel containment in an open-cycle gas-core nuclear rocket engine.

    Science.gov (United States)

    Putre, H. A.

    1971-01-01

    Analysis aimed at determining the scaling laws for the buoyancy effect on fuel containment in an open-cycle gas-core nuclear rocket engine, so conducted that experimental conditions can be related to engine conditions. The fuel volume fraction in a short coaxial flow cavity is calculated with a programmed numerical solution of the steady Navier-Stokes equations for isothermal, variable density fluid mixing. A dimensionless parameter B, called the Buoyancy number, was found to correlate the fuel volume fraction for large accelerations and various density ratios. This parameter has the value B = 0 for zero acceleration, and B = 350 for typical engine conditions.

  6. Catalytic reduction of NOx in gasoline engine exhaust over copper- and nickel-exchanged X-zeolite catalysts

    International Nuclear Information System (INIS)

    Bhattacharyya, S.; Das, R.K.

    2001-01-01

    Catalytic removal of NO x in engine exhaust gases can be accomplished by non-selective reduction, selective reduction and decomposition. Noble metals are extensively used for non-selective reduction of NO x and up to 90% of engine NO x emissions can be reduced in a stoichiometric exhaust. This requirement of having the stoichiometric fuel-air ratio acts against efficiency improvement of engines. Selective NO x reduction in the presence of different reductants such as, NH 3 , urea or hydrocarbons, requires close control of the amount of reductant being injected which otherwise may be emitted as a pollutant. Catalytic decomposition is the best option for NO x removal. Nevertheless, catalysts which are durable, economic and active for NO x reduction at normal engine exhaust temperature ranges are still being investigated. Three catalysts based on X-zeolite have been developed by exchanging the Na+ ion with copper, nickel and copper-nickel metal ions and applied to the exhaust of a stationary gasoline engine to explore their potential for catalytic reduction of NO x under a wide range of engine and exhaust conditions. Some encouraging results have been obtained. The catalyst Cu-X exhibits much better NO x reduction performance at any temperature in comparison to Cu-Ni-X and Ni-X; while Cu-Ni-X catalyst exhibits slightly better performance than Ni-X catalyst. Maximum NO x efficiency achieved with Cu-X catalyst is 59.2% at a space velocity (sv) of 31 000 h -1 ; while for Cu-Ni-X and Ni-X catalysts the equivalent numbers are 60.4% and 56% respectively at a sv of 22 000 h -1 . Unlike noble metals, the doped X-zeolite catalysts exhibit significant NO x reduction capability for a wide range of air/fuel ratio and with a slower rate of decline as well with increase in air/fuel ratio. (author)

  7. Theoretical and Experimental Aspects of Acoustic Modelling of Engine Exhaust Systems with Applications to a Vacuum Pump

    Science.gov (United States)

    Sridhara, Basavapatna Sitaramaiah

    In an internal combustion engine, the engine is the noise source and the exhaust pipe is the main transmitter of noise. Mufflers are often used to reduce engine noise level in the exhaust pipe. To optimize a muffler design, a series of experiments could be conducted using various mufflers installed in the exhaust pipe. For each configuration, the radiated sound pressure could be measured. However, this is not a very efficient method. A second approach would be to develop a scheme involving only a few measurements which can predict the radiated sound pressure at a specified distance from the open end of the exhaust pipe. In this work, the engine exhaust system was modelled as a lumped source-muffler-termination system. An expression for the predicted sound pressure level was derived in terms of the source and termination impedances, and the muffler geometry. The pressure source and monopole radiation models were used for the source and the open end of the exhaust pipe. The four pole parameters were used to relate the acoustic properties at two different cross sections of the muffler and the pipe. The developed formulation was verified through a series of experiments. Two loudspeakers and a reciprocating type vacuum pump were used as sound sources during the tests. The source impedance was measured using the direct, two-load and four-load methods. A simple expansion chamber and a side-branch resonator were used as mufflers. Sound pressure level measurements for the prediction scheme were made for several source-muffler and source-straight pipe combinations. The predicted and measured sound pressure levels were compared for all cases considered. In all cases, correlation of the experimental results and those predicted by the developed expressions was good. Predicted and measured values of the insertion loss of the mufflers were compared. The agreement between the two was good. Also, an error analysis of the four-load method was done.

  8. Engine performances and exhaust gas characteristics of methanol-fueled two-cycle engines. Kogata ni cycle ter dot methanol kikan no seino ni oyobosu shoinshi no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Sawa, N.; Kajitani, S. (Ibaraki Univ., Ibaraki (Japan). Faculty of Engineerineering); Hayashi, S.; Kubota, Y. (Muroran Inst. of Technology, Muroran (Japan))

    1990-10-25

    Regarding crank case compressed two cycle engine, feasibility of methanol-fueled engine was investigated by studying effective factors on properties of power, combustion, and exhaust gas. For the experiment, air-cooling single cylinder engine was used of which specification was shown by table. As for the experiment, quantities of in-taken air, fuel consumption, torque, and composition of exhaust gas were measured under various conditions. As the consideration of experimental results, those were obtained that less exhaust gas with high performance operation of tow-cycle engie was achieved, too, by using diluted mixture gas of methanol, and that problems were found to be studied for the realization of high compression ratio. 12 refs., 13 figs., 1 tab.

  9. Conceptual Engine System Design for NERVA derived 66.7KN and 111.2KN Thrust Nuclear Thermal Rockets

    International Nuclear Information System (INIS)

    Fittje, James E.; Buehrle, Robert J.

    2006-01-01

    The Nuclear Thermal Rocket concept is being evaluated as an advanced propulsion concept for missions to the moon and Mars. A tremendous effort was undertaken during the 1960's and 1970's to develop and test NERVA derived Nuclear Thermal Rockets in the 111.2 KN to 1112 KN pound thrust class. NASA GRC is leveraging this past NTR investment in their vehicle concepts and mission analysis studies, and has been evaluating NERVA derived engines in the 66.7 KN to the 111.2 KN thrust range. The liquid hydrogen propellant feed system, including the turbopumps, is an essential component of the overall operation of this system. The NASA GRC team is evaluating numerous propellant feed system designs with both single and twin turbopumps. The Nuclear Engine System Simulation code is being exercised to analyze thermodynamic cycle points for these selected concepts. This paper will present propellant feed system concepts and the corresponding thermodynamic cycle points for 66.7 KN and 111.2 KN thrust NTR engine systems. A pump out condition for a twin turbopump concept will also be evaluated, and the NESS code will be assessed against the Small Nuclear Rocket Engine preliminary thermodynamic data

  10. Concept Assessment of a Fission Fragment Rocket Engine (FFRE) Propelled Spacecraft

    Science.gov (United States)

    Werka, Robert; Clark, Rod; Sheldon, Rob; Percy, Tom

    2012-01-01

    The March, 2012 issue of Aerospace America stated that ?the near-to-medium prospects for applying advanced propulsion to create a new era of space exploration are not very good. In the current world, we operate to the Moon by climbing aboard a Carnival Cruise Lines vessel (Saturn 5), sail from the harbor (liftoff) shedding whole decks of the ship (staging) along the way and, having reached the return leg of the journey, sink the ship (burnout) and return home in a lifeboat (Apollo capsule). Clearly this is an illogical way to travel, but forced on Explorers by today's propulsion technology. However, the article neglected to consider the one propulsion technology, using today's physical principles that offer continuous, substantial thrust at a theoretical specific impulse of 1,000,000 sec. This engine unequivocally can create a new era of space exploration that changes the way spacecraft operate. Today's space Explorers could travel in Cruise Liner fashion using the technology not considered by Aerospace America, the novel Dusty Plasma Fission Fragment Rocket Engine (FFRE). This NIAC study addresses the FFRE as well as its impact on Exploration Spacecraft design and operation. It uses common physics of the relativistic speed of fission fragments to produce thrust. It radiatively cools the fissioning dusty core and magnetically controls the fragments direction to practically implement previously patented, but unworkable designs. The spacecraft hosting this engine is no more complex nor more massive than the International Space Station (ISS) and would employ the successful ISS technology for assembly and check-out. The elements can be lifted in "chunks" by a Heavy Lift Launcher. This Exploration Spacecraft would require the resupply of small amounts of nuclear fuel for each journey and would be an in-space asset for decades just as any Cruise Liner on Earth. This study has synthesized versions of the FFRE, integrated one concept onto a host spacecraft designed for

  11. Impact of methanol-gasoline fuel blend on the fuel consumption and exhaust emission of a SI engine

    Science.gov (United States)

    Rifal, Mohamad; Sinaga, Nazaruddin

    2016-04-01

    In this study, the effect of methanol-gasoline fuel blend (M15, M30 and M50) on the fuel consumption and exhaust emission of a spark ignition engine (SI) were investigated. In the experiment, an engine four-cylinder, four stroke injection system (engine of Toyota Kijang Innova 1TR-FE) was used. Test were did to know the relation of fuel consumption and exhaust emission (CO, CO2, HC) were analyzed under the idle throttle operating condition and variable engine speed ranging from 1000 to 4000 rpm. The experimental result showed that the fuel consumption decrease with the use of methanol. It was also shown that the CO and HC emission were reduced with the increase methanol content while CO2 were increased.

  12. Emission Characteristics for a Homogeneous Charged Compression Ignition Diesel Engine with Exhaust Gas Recirculation Using Split Injection Methodology

    Directory of Open Access Journals (Sweden)

    Changhee Lee

    2017-12-01

    Full Text Available Due to the serious issues caused by air pollution and global warming, emission regulations are becoming stricter. New technologies that reduce NOx and PM emissions are needed. To cope with these social exhaust gas regulation demands, many advanced countries are striving to develop eco-friendly vehicles in order to respond to stricter emissions regulations. The homogeneous charged compression ignition engine (HCCI incorporates a multi-stage combustion engine with multiple combustion modes, catalyst, direct fuel injection and partial mixing combustion. In this study, the HCCI combustion was applied to analyze and review the results of engines applying HCCI combustion without altering the conventional engine specifications. The optimization of exhaust gas recirculation (EGR and compression ratio changes provides an optimal fuel economy. In this study, potential for optimum economy within the range of IMEP 0.8 MPa has been evaluated.

  13. Investigation of Deposit Formation Mechanisms for Engine In-cylinder Combustion and Exhaust Systems Using Quantitative Analysis and Sustainability Study

    Science.gov (United States)

    Ye, Z.; Meng, Q.; Mohamadian, H. P.; Wang, J. T.; Chen, L.; Zhu, L.

    2007-06-01

    The formation of SI engine combustion deposits is a complex phenomenon which depends on various factors of fuel, oil, additives, and engine. The goal of this study is to examine the effects of operating conditions, gasoline, lubricating oil, and additives on deposit formation. Both an experimental investigation and theoretical analysis are conducted on a single cylinder engine. As a result, the impact of deposits on engine performance and exhaust emissions (HC, NO x ) has been indicated. Using samples from a cylinder head and exhaust pipe as well as switching gases via the dual-gas method (N2, O2), the deposit formation mechanism is thoroughly investigated via the thermogravity analysis approach, where the roles of organic, inorganic, and volatile components of fuel, additives, and oil on deposit formation are identified from thermogravity curves. Sustainable feedback control design is then proposed for potential emission control and performance optimization

  14. Comparison of aldehyde emissions simulation with FTIR measurements in the exhaust of a spark ignition engine fueled by ethanol

    Science.gov (United States)

    Zarante, Paola Helena Barros; Sodré, José Ricardo

    2018-02-01

    This work presents a numerical simulation model for aldehyde formation and exhaust emissions from ethanol-fueled spark ignition engines. The aldehyde simulation model was developed using FORTRAN software, with the input data obtained from the dedicated engine cycle simulation software AVL BOOST. The model calculates formaldehyde and acetaldehyde concentrations from post-flame partial oxidation of methane, ethane and unburned ethanol. The calculated values were compared with experimental data obtained from a mid-size sedan powered by a 1.4-l spark ignition engine, tested on a chassis dynamometer. Exhaust aldehyde concentrations were determined using a Fourier Transform Infrared (FTIR) Spectroscopy analyzer. In general, the results demonstrate that the concentrations of aldehydes and the source elements increased with engine speed and exhaust gas temperature. The measured acetaldehyde concentrations showed values from 3 to 6 times higher than formaldehyde in the range studied. The model could predict reasonably well the qualitative experimental trends, with the quantitative results showing a maximum discrepancy of 39% for acetaldehyde concentration and 21 ppm for exhaust formaldehyde.

  15. Identification of black-box linear models : the case of thermal periodic contact of exhaust valves in internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Shojaeefard, M.H.; Fazelpour, M. [Iran Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Dept. of Automotive Engineering; Goudarzi, K. [Iran Univ. of Science and Technology, Tehran (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2009-07-01

    In internal combustion engines, hot exhaust gases that pass through the exhaust valve lead to high temperatures in the exhaust valve and the valve seat. Heat must be transferred from the exhaust valve to valve seat as they come in contact with each other during the opening and closing cycle in order to avoid damaging the exhaust valve. The heat transfer rate from the valve to valve seat is a function of many factors, including the thermal contact conductance (TCC) between the valve and valve seat. The objective of this study was to experimentally calculate the TCC for six different frequencies in the quasi-steady-state condition and also to obtain a transfer function to estimate the exhaust valve temperature by using black-box models of system identification. Periodic contact was taken into consideration in the study. The paper presented the experimental setup including the loading system, heat and cooling system, temperature measurement system, specimens properties, and data acquisition system. The paper also described the test procedure and experimental results. System identification was also described. It was concluded that the TCC decreased as the frequency of contact increased. The temperature transfer function was calculated by using the system identification method and having the temperatures at both sides of the contact surface. By knowing the temperature of one rod, the temperature of the other rod was estimated with high accuracy. 16 refs., 4 tabs., 7 figs.

  16. Verification on spray simulation of a pintle injector for liquid rocket engine

    Science.gov (United States)

    Son, Min; Yu, Kijeong; Radhakrishnan, Kanmaniraja; Shin, Bongchul; Koo, Jaye

    2016-02-01

    The pintle injector used for a liquid rocket engine is a newly re-attracted injection system famous for its wide throttle ability with high efficiency. The pintle injector has many variations with complex inner structures due to its moving parts. In order to study the rotating flow near the injector tip, which was observed from the cold flow experiment using water and air, a numerical simulation was adopted and a verification of the numerical model was later conducted. For the verification process, three types of experimental data including velocity distributions of gas flows, spray angles and liquid distribution were all compared using simulated results. The numerical simulation was performed using a commercial simulation program with the Eulerian multiphase model and axisymmetric two dimensional grids. The maximum and minimum velocities of gas were within the acceptable range of agreement, however, the spray angles experienced up to 25% error when the momentum ratios were increased. The spray density distributions were quantitatively measured and had good agreement. As a result of this study, it was concluded that the simulation method was properly constructed to study specific flow characteristics of the pintle injector despite having the limitations of two dimensional and coarse grids.

  17. EFFECT OF OXYGENATED HYDROCARBON ADDITIVES ON EXHAUST EMISSIONS OF A DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    C. Sundar Raj

    2010-12-01

    Full Text Available The use of oxygenated fuels seems to be a promising solution for reducing particulate emissions in existing and future diesel motor vehicles. In this work, the influence of the addition of oxygenated hydrocarbons to diesel fuels on performance and emission parameters of a diesel engine is experimentally studied. 3-Pentanone (C5H10O and Methyl anon (C7H12O were used as oxygenated fuel additives. It was found that the addition of oxygenated hydrocarbons reduced the production of soot precursors with respect to the availability of oxygen content in the fuel. On the other hand, a serious increase of NOx emissions is observed. For this reason the use of exhaust gas recirculation (EGR to control NOx emissions is examined. From the analysis of it is examined experimental findings, it is seen that the use of EGR causes a sharp reduction in NOx and smoke simultaneously. On the other hand, EGR results in a slight reduction of engine efficiency and maximum combustion pressure which in any case does not alter the benefits obtained from the oxygenated fuel.

  18. Control of PCDDs/PCDFs, PCBs and PAHs emissions in exhaust of landfill gas fed engines

    Energy Technology Data Exchange (ETDEWEB)

    Idczak, F.; Dengis, P.; Duchateau, P.; Petitjean, S. [ISSeP, Liege (Belgium)

    2004-09-15

    Wallonia in Belgium, like many countries around the world, planned to reduce amounts of waste generated by human activity and stored in landfills. Since they experienced a couple of crisis situations in the past, both with former and presently used landfill sites, authorities launched a demanding landfill monitoring program which covers now 9 out of the 10 major sites. Biogas produced in these landfills are collected and eliminated in two different ways. Either simply burned in a flare, or, when the methane grade and flow are high enough, the biogas can be burned in electricity producing engines. This later use represents an energy recovery from the waste. In the context of difficulty for landfill sites to be accepted by the public (the well-known NIMBY phenomenon), the question has been raised whether combustion of the biogas did not entail production of dioxins and other polyaromatic compounds. For the exhaust gases of engines operated with biogas, a check on the presence of dioxins and associated organic pollutants, composed of three different runs or days of sampling for each of 5 landfill sites was performed upon demand of responsible authorities.

  19. Biodiesel from lemon and lemon grass oil and its effect on engine performance and exhaust emission

    Science.gov (United States)

    Dhivagar, R.; Sundararaj, S.; Vignesh, V. R.

    2018-03-01

    In the present scenario many developing countries are depending on oil producing nations for their fuel resources. Due to demand and scarcity of the fuel, there has been a huge increase in fuel prices. The vehicular population is also continuously increasing and becoming a great menace to peoples. This paper aims to provide an alternate solution for petroleum based fuels. It suggests that biodiesel produced from lemon and lemon grass oil can be used as an alternative fuel. This work investigates the thermal performance of four stroke diesel engine using blends of biodiesel and diesel as a fuel. Performance parameters like brake thermal efficiency, mechanical efficiency and specific fuel consumption were measured at different loads for diesel and various combination of biofuel (L10, L20, and L30). The maximum brake thermal efficiency obtained is about 26.12%for L20 which is slightly higher than that of diesel (24.91%). Engine experimental results showed that exhaust emissions including CO2 and HC were reduced by 6% and 5% for L20 mixture of biodiesel whereas CO emission was as same as diesel. However, there was increase in NOxby 26% to the diesel fuel.

  20. The Effect of Fuel Dose Division on The Emission of Toxic Components in The Car Diesel Engine Exhaust Gas

    Directory of Open Access Journals (Sweden)

    Pietras Dariusz

    2016-09-01

    Full Text Available The article discusses the effect of fuel dose division in the Diesel engine on smoke opacity and composition of the emitted exhaust gas. The research activities reported in the article include experimental examination of a small Diesel engine with Common Rail type supply system. The tests were performed on the engine test bed equipped with an automatic data acquisition system which recorded all basic operating and control parameters of the engine, and smoke opacity and composition of the exhaust gas. The parameters measured during the engine tests also included the indicated pressure and the acoustic pressure. The tests were performed following the pre-established procedure in which 9 engine operation points were defined for three rotational speeds: 1500, 2500 and 3500 rpm, and three load levels: 25, 40 and 75 Nm. At each point, the measurements were performed for 7 different forms of fuel dose injection, which were: the undivided dose, the dose divided into two or three parts, and three different injection advance angles for the undivided dose and that divided into two parts. The discussion of the obtained results includes graphical presentation of contests of hydrocarbons, carbon oxide, and nitrogen oxides in the exhaust gas, and its smoke opacity. The presented analyses referred to two selected cases, out of nine examined engine operation points. In these cases the fuel dose was divided into three parts and injected at the factory set control parameters. The examination has revealed a significant effect of fuel dose division on the engine efficiency, and on the smoke opacity and composition of the exhaust gas, in particular the content of nitrogen oxides. Within the range of low loads and rotational speeds, dividing the fuel dose into three parts clearly improves the overall engine efficiency and significantly decreases the concentration of nitrogen oxides in the exhaust gas. Moreover, it slightly decreases the contents of hydrocarbons and

  1. Observations and model calculations of B747 engine exhaust products at cruise altitude and inferred initial OH emissions

    Energy Technology Data Exchange (ETDEWEB)

    Tremmel, H.G.; Schlager, H.; Konopka, P.; Schulte, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere; Arnold, F.; Klemm, M.; Droste-Franke, B. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

    1997-06-01

    NO{sub y} (NO, HNO{sub 2} and HNO{sub 3}) exhaust emissions in the near-field plume of two B747 jet airliners cruising in the upper troposphere were measured in situ using the DLR Falcon research aircraft. In addition CO{sub 2} was measured providing exhaust plume dilution rates for the species. The observations were used to estimate the initial OH concentration and NO{sub 2}/NO{sub x} ratio at the engine exit and the combustor exit by back calculations using a chemistry box model. From the two different plume events, and using two different model simulation modes in each case, we inferred OH emission indices EI(OH) = 0.32-0.39 g/kg fuel (OH{sub 0} = 9-14.4 ppmv) and (NO{sub 2}/NO{sub x}){sub 0} = 0.12-0.17. Furthermore, our results indicate that the chemistry of the exhaust species during the short period between the combustion chamber exit and the engine exit must be considered, because OH is already consumed to a great extent in this engine section, due to conversion to HNO{sub 2} and HNO{sub 3}. For the engines discussed here, the modeled OH concentration between combustor exit und engine exit decreases by a factor of about 350, leading to OH concentrations of 1-2.10{sup 12} molec/cm{sup 3} at the engine exit. (orig.) 45 refs.

  2. Performance analysis of exhaust heat recovery using organic Rankine cycle in a passenger car with a compression ignition engine

    Science.gov (United States)

    Ghilvacs, M.; Prisecaru, T.; Pop, H.; Apostol, V.; Prisecaru, M.; Pop, E.; Popescu, Gh; Ciobanu, C.; Mohanad, A.; Alexandru, A.

    2016-08-01

    Compression ignition engines transform approximately 40% of the fuel energy into power available at the crankshaft, while the rest part of the fuel energy is lost as coolant, exhaust gases and other waste heat. An organic Rankine cycle (ORC) can be used to recover this waste heat. In this paper, the characteristics of a system combining a compression ignition engine with an ORC which recover the waste heat from the exhaust gases are analyzed. The performance map of the diesel engine is measured on an engine test bench and the heat quantities wasted by the exhaust gases are calculated over the engine's entire operating region. Based on this data, the working parameters of ORC are defined, and the performance of a combined engine-ORC system is evaluated across this entire region. The results show that the net power of ORC is 6.304kW at rated power point and a maximum of 10% reduction in brake specific fuel consumption can be achieved.

  3. Exhaust Aftertreatment and Low Pressure Loop EGR Applied to an Off-Highway Engine

    Energy Technology Data Exchange (ETDEWEB)

    Baumgard, Kirby; Triana, Antonio; Johnson, John; Yang, Song; Premchand, Kiran

    2006-01-30

    packing density inside the porous wall were 1 to 5 kg/m{sup 3}; and percolation factors were 0.81 to 0.97. Average particulate layer permeability was 1.95 x 10{sup -14} m{sup 2}. Solid particulate layer packing density values were between 11 and 128 kg/m{sup 3}. These values were in good agreement with the Peclet number correlation theory reported in the literature. NO{sub 2}-assisted oxidation of PM in the DPF showed experimentally that a significant reduction of the pressure drop can be achieved (<8 kPa) when sufficient NO{sub 2} (>120 ppm) is available and high exhaust gas temperatures ({approx}360-460 C) can be maintained, even at high PM loadings (low NO{sub 2}/solid PM ratios). The CRT{trademark} (DOC-DPF system) showed limited advantages when used with high PM rates (low NOx/PM ratios) in combination with a low pressure loop EGR strategy for a continuous operation of an engine-exhaust aftertreatment system. The 8.1-liter engine was not designed for low-pressure loop EGR and when the EGR was added the NOx emissions were reduced but the PM emissions increased. This corresponds to the well known NOx to PM relationship in which if the NOx is reduced the PM emissions increase. In order for this technology to be successful on this engine family, the engine out PM emissions must be reduced. These results led to Task II. Task II objective was to meet the interim Tier 4 standards using the CCRT{trademark} technology applied to an advanced 6.8 liter John Deere engine. The advanced engine incorporated a 4 valve head, required additional EGR, an advanced high pressure common rail fuel system and a better matched turbocharger. The EGR system was optimized and the goal of less than 2 g/kWh NOx and less than 0.02 g/kWh PM were achieved over the 8 mode test. Again, experimental data was provided to Michigan Tech to study the passive regeneration of the CCRT{trademark} technology. Two computer models, i.e., the MTU 1-D DOC model and the MTU 1-D 2-layer CPF model were developed as

  4. Aircraft engine exhaust emissions and other airport-related contributions to ambient air pollution: A review

    Science.gov (United States)

    Masiol, Mauro; Harrison, Roy M.

    2014-10-01

    Civil aviation is fast-growing (about +5% every year), mainly driven by the developing economies and globalisation. Its impact on the environment is heavily debated, particularly in relation to climate forcing attributed to emissions at cruising altitudes and the noise and the deterioration of air quality at ground-level due to airport operations. This latter environmental issue is of particular interest to the scientific community and policymakers, especially in relation to the breach of limit and target values for many air pollutants, mainly nitrogen oxides and particulate matter, near the busiest airports and the resulting consequences for public health. Despite the increased attention given to aircraft emissions at ground-level and air pollution in the vicinity of airports, many research gaps remain. Sources relevant to air quality include not only engine exhaust and non-exhaust emissions from aircraft, but also emissions from the units providing power to the aircraft on the ground, the traffic due to the airport ground service, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants for passengers and operators, intermodal transportation systems, and road traffic for transporting people and goods in and out to the airport. Many of these sources have received inadequate attention, despite their high potential for impact on air quality. This review aims to summarise the state-of-the-art research on aircraft and airport emissions and attempts to synthesise the results of studies that have addressed this issue. It also aims to describe the key characteristics of pollution, the impacts upon global and local air quality and to address the future potential of research by highlighting research needs.

  5. Innovative MAN Euro V engines without exhaust aftertreatment; Innovative MAN Euro V Motorisierung ohne Abgasnachbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Held, W.; Raab, G.; Schaller, K.V.; Gotre, W.; Lehmann, H.; Moeller, H.; Schroeppel, W. [MAN Nutzfahrzeuge AG, Muenchen (Germany); MAN Nutzfahrzeuge AG, Nuernberg (Germany); MAN Nutzfahrzeuge AG, Steyr (Austria)

    2009-07-01

    MAN Nutzfahrzeuge AG (Munich, Federal Republic of Germany) always is eager to offer products for the respective markets whereby the products are interesting for the customer under economic criteria. Additionally, the products shall not lack in the travelling comfort under consideration of the legal emission borders. Thus, a AdBlue {sup registered} free technology for all MAN series was already offered before the legal introduction of EURO IV. This technology is based on an internal-motor solution with external, cooled AGR and a PM-Cat {sup registered} -filter. This solution is esteemed highly by our customers because apart from the well-known advantages in relation to a SCR technology there were no losses with the operating cost. With EURO V which is inserted in some countries MAN Nutzfahrzeuge AG returns to a long-term experience with SCR technology. The motivation for the development of a AdBlue {sup registered} free solution was the positive feedback of our customers on the basis of MAN EURO IV AGR/PM Cat technology. With the developed EURO V AGR solution, other EURO IV solutions in line with market conditions for the 'Emerging markets' can be derived with which a technology without exhaust post-treatment can be offered worldwide for our customers. This technology presents the basis for a platform concept EURO IV/V and EURO VI. In this concept, EURO IV can be presented without subsequent treatment of exhaust gases, EURO V in connection with an Oxicat and EURO VI with a SCRT system. Here, the vehicle/engine concept presents the most important components for the individual series in particular. By means of these components, the goal EURO V was achieved internal-motor without losses of operating cost and life span in relation to SCR technologies.

  6. High Thermal Conductivity NARloy-Z-Diamond Composite Liner for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar; Greene, Sandra

    2015-01-01

    NARloy-Z (Cu-3Ag-0.5Zr) alloy is state-of-the-art combustion chamber liner material used in liquid propulsion engines such as the RS-68 and RS-25. The performance of future liquid propulsion systems can be improved significantly by increasing the heat transfer through the combustion chamber liner. Prior work1 done at NASA Marshall Space Flight Center (MSFC) has shown that the thermal conductivity of NARloy-Z alloy can be improved significantly by embedding high thermal conductivity diamond particles in the alloy matrix to form NARloy-Z-diamond composite (fig. 1). NARloy-Z-diamond composite containing 40vol% diamond showed 69% higher thermal conductivity than NARloy-Z. It is 24% lighter than NARloy-Z and hence the density normalized thermal conductivity is 120% better. These attributes will improve the performance and life of the advanced rocket engines significantly. The research work consists of (a) developing design properties (thermal and mechanical) of NARloy-Z-D composite, (b) fabrication of net shape subscale combustion chamber liner, and (c) hot-fire testing of the liner to test performance. Initially, NARloy-Z-D composite slabs were made using the Field Assisted Sintering Technology (FAST) for the purpose of determining design properties. In the next step, a cylindrical shape was fabricated to demonstrate feasibility (fig. 3). The liner consists of six cylinders which are sintered separately and then stacked and diffusion bonded to make the liner (fig. 4). The liner will be heat treated, finish-machined, and assembled into a combustion chamber and hot-fire tested in the MSFC test facility (TF 115) to determine perform.

  7. X-ray Radiography Measurements of Shear Coaxial Rocket Injectors

    Science.gov (United States)

    2013-05-07

    Shear coaxial jets can be found in a number of combustion devices – Turbofan engine exhaust , air blast furnaces, and liquid rocket engines ...water and gaseous nitro-gen as propellant simulants at atmospheric backpressure , the effect of momentum flux ratio and mass flux ratio, are...the effect of momentum flux ratio, mass flux ratio and post thickness on the liquid mass distribution – Use quantitative centerline profiles to

  8. Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

    Science.gov (United States)

    Alanen, Jenni; Simonen, Pauli; Saarikoski, Sanna; Timonen, Hilkka; Kangasniemi, Oskari; Saukko, Erkka; Hillamo, Risto; Lehtoranta, Kati; Murtonen, Timo; Vesala, Hannu; Keskinen, Jorma; Rönkkö, Topi

    2017-07-01

    Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM) chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6-268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA) formation potential was measured to be 9-20 mg kgfuel-1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize - more than half an hour - which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission source and system temperatures. Sulfate was

  9. Comparison of primary and secondary particle formation from natural gas engine exhaust and of their volatility characteristics

    Directory of Open Access Journals (Sweden)

    J. Alanen

    2017-07-01

    Full Text Available Natural gas usage in the traffic and energy production sectors is a growing trend worldwide; thus, an assessment of its effects on air quality, human health and climate is required. Engine exhaust is a source of primary particulate emissions and secondary aerosol precursors, which both contribute to air quality and can cause adverse health effects. Technologies, such as cleaner engines or fuels, that produce less primary and secondary aerosols could potentially significantly decrease atmospheric particle concentrations and their adverse effects. In this study, we used a potential aerosol mass (PAM chamber to investigate the secondary aerosol formation potential of natural gas engine exhaust. The PAM chamber was used with a constant UV-light voltage, which resulted in relatively long equivalent atmospheric ages of 11 days at most. The studied retro-fitted natural gas engine exhaust was observed to form secondary aerosol. The mass of the total aged particles, i.e., particle mass measured downstream of the PAM chamber, was 6–268 times as high as the mass of the emitted primary exhaust particles. The secondary organic aerosol (SOA formation potential was measured to be 9–20 mg kgfuel−1. The total aged particles mainly consisted of organic matter, nitrate, sulfate and ammonium, with the fractions depending on exhaust after-treatment and the engine parameters used. Also, the volatility, composition and concentration of the total aged particles were found to depend on the engine operating mode, catalyst temperature and catalyst type. For example, a high catalyst temperature promoted the formation of sulfate particles, whereas a low catalyst temperature promoted nitrate formation. However, in particular, the concentration of nitrate needed a long time to stabilize – more than half an hour – which complicated the conclusions but also indicates the sensitivity of nitrate measurements on experimental parameters such as emission

  10. The effect of rapeseed oil methyl ester on direct injection Diesel engine performance and exhaust emissions

    International Nuclear Information System (INIS)

    Labeckas, Gvidonas; Slavinskas, Stasys

    2006-01-01

    This article presents the comparative bench testing results of a four stroke, four cylinder, direct injection, unmodified, naturally aspirated Diesel engine when operating on neat RME and its 5%, 10%, 20% and 35% blends with Diesel fuel. The purpose of this research is to examine the effects of RME inclusion in Diesel fuel on the brake specific fuel consumption (bsfc) of a high speed Diesel engine, its brake thermal efficiency, emission composition changes and smoke opacity of the exhausts. The brake specific fuel consumption at maximum torque (273.5 g/kW h) and rated power (281 g/kW h) for RME is higher by 18.7% and 23.2% relative to Diesel fuel. It is difficult to determine the RME concentration in Diesel fuel that could be recognised as equally good for all loads and speeds. The maximum brake thermal efficiency varies from 0.356 to 0.398 for RME and from 0.373 to 0.383 for Diesel fuel. The highest fuel energy content based economy (9.36-9.61 MJ/kW h) is achieved during operation on blend B10, whereas the lowest ones belong to B35 and neat RME. The maximum NO x emissions increase proportionally with the mass percent of oxygen in the biofuel and engine speed, reaching the highest values at the speed of 2000 min -1 , the highest being 2132 ppm value for the B35 blend and 2107 ppm for RME. The carbon monoxide, CO, emissions and visible smoke emerging from the biodiesel over all load and speed ranges are lower by up to 51.6% and 13.5% to 60.3%, respectively. The carbon dioxide, CO 2 , emissions along with the fuel consumption and gas temperature, are slightly higher for the B20 and B35 blends and neat RME. The emissions of unburned hydrocarbons, HC, for all biofuels are low, ranging at 5-21 ppm levels

  11. Exhaust gas emissions evaluation in the flight of a multirole fighter equipped with a F100-PW-229 turbine engine

    Directory of Open Access Journals (Sweden)

    Markowski Jarosław

    2017-01-01

    Full Text Available The issue of exhaust gas emission generated by turbine engines described in ICAO Annex 16 of the International Civil Aviation Convention includes a number of procedures and requirements. Their implementation is aimed at determining the value of the engine’s environmental parameters and comparing them to the values specified in the norms. The turbine engine exhaust gas emission test procedures are defined as stationary and the operating parameters values are set according to the LTO test. The engine load setting values refer to engine operating parameters that occur when the plane is in the vicinity of airports. Such a procedure is dedicated to civilian passenger and transport aircraft. The operating conditions of a multirole fighter aircraft vary considerably from passenger aircraft and the variability of their flight characteristics requires a special approach in assessing its environmental impact. This article attempts to evaluate the exhaust gas emissions generated by the turbine engine in a multirole fighter flight using the parameters recorded by the onboard flight recorder.

  12. The Effect of Exhaust Gas Recirculation (EGR on the Emission of a Single Cylinder Spark Ignition Engine

    Directory of Open Access Journals (Sweden)

    Limyaa Mahdi Asaad

    2016-07-01

    Full Text Available A single cylinder variable compression ratio spark ignition engine type PRODIT was used in this study. The  experiments  were  conducted  with  gasoline  fuel  (80  octane  No.at  equivalence  ratio  (Ø  =1.  This study examined the effects of exhaust gas recirculation on emission. It was conducted at engine speeds (1500, 1900, 2300 and 2700 r.p.m..The  exhaust  gases  were  added  in  volumetric  ratios  of  10%,  20%  and  30%  of  the  entering  air/fuel charge. The results showed that the EGR addition decreases the CO2 concentrations, in the same time CO and HC concentrations increase remarkably.  NOx concentration decreased highly with the increase of EGR percentage at variable engine speeds and constant torque. Also, it decreased when the engine run  at  constant  speed  and  variable  engine  torque.  The  exhaust  gas  temperature  decreased  with increasing EGR ratio.

  13. Liquid rocket propulsion dynamic flow modeling using the ROCETS engineering modules in the EASY5x environment

    Science.gov (United States)

    Follett, Randolph F.; Taylor, Robert P.; Nunez, Stephen C.

    1993-01-01

    A report on the progress of porting the ROCETS (ROCket Engine Transient Simulator) into the EASY5x simulation environment is presented. Brief descriptions of each of the software systems, information regarding the actual port process, and examples comparing the results of the two systems are given. It is shown that EASY5x is a suitable environment for utilization of the ROCETS engineering modules, and that, for the example systems shown, EASY5x actually seems to give more accurate solutions than the straight ROCETS code.

  14. Reuse fo a Cold War Surveillance Drone to Flight Test a NASA Rocket Based Combined Cycle Engine

    Science.gov (United States)

    Brown, T. M.; Smith, Norm

    1999-01-01

    Plans for and early feasibility investigations into the modification of a Lockheed D21B drone to flight test the DRACO Rocket Based Combined Cycle (RBCC) engine are discussed. Modifications include the addition of oxidizer tanks, modern avionics systems, actuators, and a vehicle recovery system. Current study results indicate that the D21B is a suitable candidate for this application and will allow demonstrations of all DRACO engine operating modes at Mach numbers between 0.8 and 4.0. Higher Mach numbers may be achieved with more extensive modification. Possible project risks include low speed stability and control, and recovery techniques.

  15. Diesel engine performance and exhaust emission analysis using waste cooking biodiesel fuel with an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Ghobadian, B.; Rahimi, H.; Nikbakht, A.M.; Najafi, G. [Tarbiat Modares University, P.O. Box 14115-111, Tehran (Iran); Yusaf, T.F. [University of Southern Queensland, Toowoomba 4350 QLD (Australia)

    2009-04-15

    This study deals with artificial neural network (ANN) modeling of a diesel engine using waste cooking biodiesel fuel to predict the brake power, torque, specific fuel consumption and exhaust emissions of the engine. To acquire data for training and testing the proposed ANN, a two cylinders, four-stroke diesel engine was fuelled with waste vegetable cooking biodiesel and diesel fuel blends and operated at different engine speeds. The properties of biodiesel produced from waste vegetable oil was measured based on ASTM standards. The experimental results revealed that blends of waste vegetable oil methyl ester with diesel fuel provide better engine performance and improved emission characteristics. Using some of the experimental data for training, an ANN model was developed based on standard Back-Propagation algorithm for the engine. Multi layer perception network (MLP) was used for non-linear mapping between the input and output parameters. Different activation functions and several rules were used to assess the percentage error between the desired and the predicted values. It was observed that the ANN model can predict the engine performance and exhaust emissions quite well with correlation coefficient (R) 0.9487, 0.999, 0.929 and 0.999 for the engine torque, SFC, CO and HC emissions, respectively. The prediction MSE (Mean Square Error) error was between the desired outputs as measured values and the simulated values were obtained as 0.0004 by the model. (author)

  16. Investigation of Exhaust Backflow From a Simulated Cluster of Three Wide-Spaced Rocket Nozzles in a Near-Space Environment

    National Research Council Canada - National Science Library

    Cubbage, James M

    1965-01-01

    ... and to determine pressure and heat- transfer coefficients in the region washed by the backflow. Experiments were conducted in a 61-foot-diameter vacuum sphere using a sine solid-propellant rocket motor and a reflection plate...

  17. Techniques to assess acoustic-structure interaction in liquid rocket engines

    Science.gov (United States)

    Davis, R. Benjamin

    Acoustoelasticity is the study of the dynamic interaction between elastic structures and acoustic enclosures. In this dissertation, acoustoelasticity is considered in the context of liquid rocket engine design. The techniques presented here can be used to determine which forcing frequencies are important in acoustoelastic systems. With a knowledge of these frequencies, an analyst can either find ways to attenuate the excitation at these frequencies or alter the system in such a way that the prescribed excitations do result in a resonant condition. The end result is a structural component that is less susceptible to failure. The research scope is divided into three parts. In the first part, the dynamics of cylindrical shells submerged in liquid hydrogen (LH2) and liquid oxygen (LOX) are considered. The shells are bounded by rigid outer cylinders. This configuration gives rise to two fluid-filled cavities---an inner cylindrical cavity and an outer annular cavity. Such geometries are common in rocket engine design. The natural frequencies and modes of the fluid-structure system are computed by combining the rigid wall acoustic cavity modes and the in vacuo structural modes into a system of coupled ordinary differential equations. Eigenvalue veering is observed near the intersections of the curves representing natural frequencies of the rigid wall acoustic and the in vacuo structural modes. In the case of a shell submerged in LH2, system frequencies near these intersections are as much as 30% lower than the corresponding in vacuo structural frequencies. Due to its high density, the frequency reductions in the presence of LOX are even more dramatic. The forced responses of a shell submerged in LH2 and LOX while subject to a harmonic point excitation are also presented. The responses in the presence of fluid are found to be quite distinct from those of the structure in vacuo. In the second part, coupled mode theory is used to explore the fundamental features of

  18. Using Decision Trees to Detect and Isolate Simulated Leaks in the J-2X Rocket Engine

    Science.gov (United States)

    Schwabacher, Mark A.; Aguilar, Robert; Figueroa, Fernando F.

    2009-01-01

    The goal of this work was to use data-driven methods to automatically detect and isolate faults in the J-2X rocket engine. It was decided to use decision trees, since they tend to be easier to interpret than other data-driven methods. The decision tree algorithm automatically "learns" a decision tree by performing a search through the space of possible decision trees to find one that fits the training data. The particular decision tree algorithm used is known as C4.5. Simulated J-2X data from a high-fidelity simulator developed at Pratt & Whitney Rocketdyne and known as the Detailed Real-Time Model (DRTM) was used to "train" and test the decision tree. Fifty-six DRTM simulations were performed for this purpose, with different leak sizes, different leak locations, and different times of leak onset. To make the simulations as realistic as possible, they included simulated sensor noise, and included a gradual degradation in both fuel and oxidizer turbine efficiency. A decision tree was trained using 11 of these simulations, and tested using the remaining 45 simulations. In the training phase, the C4.5 algorithm was provided with labeled examples of data from nominal operation and data including leaks in each leak location. From the data, it "learned" a decision tree that can classify unseen data as having no leak or having a leak in one of the five leak locations. In the test phase, the decision tree produced very low false alarm rates and low missed detection rates on the unseen data. It had very good fault isolation rates for three of the five simulated leak locations, but it tended to confuse the remaining two locations, perhaps because a large leak at one of these two locations can look very similar to a small leak at the other location.

  19. Development and Hotfire Testing of Additively Manufactured Copper Combustion Chambers for Liquid Rocket Engine Applications

    Science.gov (United States)

    Gradl, Paul R.; Greene, Sandy; Protz, Chris

    2017-01-01

    NASA and industry partners are working towards fabrication process development to reduce costs and schedules associated with manufacturing liquid rocket engine components with the goal of reducing overall mission costs. One such technique being evaluated is powder-bed fusion or selective laser melting (SLM), commonly referred to as additive manufacturing (AM). The NASA Low Cost Upper Stage Propulsion (LCUSP) program was designed to develop processes and material characterization for GRCop-84 (a NASA Glenn Research Center-developed copper, chrome, niobium alloy) commensurate with powder bed AM, evaluate bimetallic deposition, and complete testing of a full scale combustion chamber. As part of this development, the process has been transferred to industry partners to enable a long-term supply chain of monolithic copper combustion chambers. To advance the processes further and allow for optimization with multiple materials, NASA is also investigating the feasibility of bimetallic AM chambers. In addition to the LCUSP program, NASA’s Marshall Space Flight Center (MSFC) has completed a series of development programs and hot-fire tests to demonstrate SLM GRCop-84 and other AM techniques. MSFC’s efforts include a 4,000 pounds-force thrust liquid oxygen/methane (LOX/CH4) combustion chamber. Small thrust chambers for 1,200 pounds-force LOX/hydrogen (H2) applications have also been designed and fabricated with SLM GRCop-84. Similar chambers have also completed development with an Inconel 625 jacket bonded to the GRCop-84 material, evaluating direct metal deposition (DMD) laser- and arc-based techniques. The same technologies for these lower thrust applications are being applied to 25,000-35,000 pounds-force main combustion chamber (MCC) designs. This paper describes the design, development, manufacturing and testing of these numerous combustion chambers, and the associated lessons learned throughout their design and development processes.

  20. Inflammation-Related Effects of Diesel Engine Exhaust Particles: Studies on Lung Cells In Vitro

    Science.gov (United States)

    Schwarze, P. E.; Totlandsdal, A. I.; Låg, M.; Refsnes, M.; Holme, J. A.; Øvrevik, J.

    2013-01-01

    Diesel exhaust and its particles (DEP) have been under scrutiny for health effects in humans. In the development of these effects inflammation is regarded as a key process. Overall, in vitro studies report similar DEP-induced changes in markers of inflammation, including cytokines and chemokines, as studies in vivo. In vitro studies suggest that soluble extracts of DEP have the greatest impact on the expression and release of proinflammatory markers. Main DEP mediators of effects have still not been identified and are difficult to find, as fuel and engine technology developments lead to continuously altered characteristics of emissions. Involved mechanisms remain somewhat unclear. DEP extracts appear to comprise components that are able to activate various membrane and cytosolic receptors. Through interactions with receptors, ion channels, and phosphorylation enzymes, molecules in the particle extract will trigger various cell signaling pathways that may lead to the release of inflammatory markers directly or indirectly by causing cell death. In vitro studies represent a fast and convenient system which may have implications for technology development. Furthermore, knowledge regarding how particles elicit their effects may contribute to understanding of DEP-induced health effects in vivo, with possible implications for identifying susceptible groups of people and effect biomarkers. PMID:23509760

  1. Compact high-speed MWIR spectrometer applied to monitor CO2 exhaust dynamics from a turbojet engine

    Science.gov (United States)

    Linares-Herrero, R.; Vergara, G.; Gutiérrez Álvarez, R.; Fernández Montojo, C.; Gómez, L. J.; Villamayor, V.; Baldasano Ramírez, A.; Montojo, M. T.; Archilla, V.; Jiménez, A.; Mercader, D.; González, A.; Entero, A.

    2013-05-01

    Dfgfdg Due to international environmental regulations, aircraft turbojet manufacturers are required to analyze the gases exhausted during engine operation (CO, CO2, NOx, particles, unburned hydrocarbons (aka UHC), among others).Standard procedures, which involve sampling the gases from the exhaust plume and the analysis of the emissions, are usually complex and expensive, making a real need for techniques that allow a more frequent and reliable emissions measurements, and a desire to move from the traditional gas sampling-based methods to real time and non-intrusive gas exhaust analysis, usually spectroscopic. It is expected that the development of more precise and faster optical methods will provide better solutions in terms of performance/cost ratio. In this work the analysis of high-speed infrared emission spectroscopy measurements of plume exhaust are presented. The data was collected during the test trials of commercial engines carried out at Turbojet Testing Center-INTA. The results demonstrate the reliability of the technique for studying and monitoring the dynamics of the exhausted CO2 by the observation of the infrared emission of hot gases. A compact (no moving parts), high-speed, uncooled MWIR spectrometer was used for the data collection. This device is capable to register more than 5000 spectra per second in the infrared band ranging between 3.0 and 4.6 microns. Each spectrum is comprised by 128 spectral subbands with aband width of 60 nm. The spectrometer operated in a passive stand-off mode and the results from the measurements provided information of both the dynamics and the concentration of the CO2 during engine operation.

  2. Ongoing Analysis of Rocket Based Combined Cycle Engines by the Applied Fluid Dynamics Analysis Group at Marshall Space Flight Center

    Science.gov (United States)

    Ruf, Joseph; Holt, James B.; Canabal, Francisco

    1999-01-01

    This paper presents the status of analyses on three Rocket Based Combined Cycle configurations underway in the Applied Fluid Dynamics Analysis Group (TD64). TD64 is performing computational fluid dynamics analysis on a Penn State RBCC test rig, the proposed Draco axisymmetric RBCC engine and the Trailblazer engine. The intent of the analysis on the Penn State test rig is to benchmark the Finite Difference Navier Stokes code for ejector mode fluid dynamics. The Draco engine analysis is a trade study to determine the ejector mode performance as a function of three engine design variables. The Trailblazer analysis is to evaluate the nozzle performance in scramjet mode. Results to date of each analysis are presented.

  3. Comparison of Airway Responses Induced in a Mouse Model by the Gas and Particulate Fractions of Gasoline Direct Injection Engine Exhaust.

    Science.gov (United States)

    Maikawa, Caitlin L; Zimmerman, Naomi; Ramos, Manuel; Shah, Mittal; Wallace, James S; Pollitt, Krystal J Godri

    2018-03-01

    Diesel exhaust has been associated with asthma, but its response to other engine emissions is not clear. The increasing prevalence of vehicles with gasoline direct injection (GDI) engines motivated this study, and the objective was to evaluate pulmonary responses induced by acute exposure to GDI engine exhaust in an allergic asthma murine model. Mice were sensitized with an allergen to induce airway hyperresponsiveness or treated with saline (non-allergic group). Animals were challenged for 2-h to exhaust from a laboratory GDI engine operated at conditions equivalent to a highway cruise. Exhaust was filtered to assess responses induced by the particulate and gas fractions. Short-term exposure to particulate matter from GDI engine exhaust induced upregulation of genes related to polycyclic aromatic hydrocarbon (PAH) metabolism ( Cyp1b1 ) and inflammation ( TNFα ) in the lungs of non-allergic mice. High molecular weight PAHs dominated the particulate fraction of the exhaust, and this response was therefore likely attributable to the presence of these PAHs. The particle fraction of GDI engine exhaust further contributed to enhanced methacholine responsiveness in the central and peripheral tissues in animals with airway hyperresponsiveness. As GDI engines gain prevalence in the vehicle fleet, understanding the health impacts of their emissions becomes increasingly important.

  4. Comparison of Airway Responses Induced in a Mouse Model by the Gas and Particulate Fractions of Gasoline Direct Injection Engine Exhaust

    Directory of Open Access Journals (Sweden)

    Caitlin L. Maikawa

    2018-03-01

    Full Text Available Diesel exhaust has been associated with asthma, but its response to other engine emissions is not clear. The increasing prevalence of vehicles with gasoline direct injection (GDI engines motivated this study, and the objective was to evaluate pulmonary responses induced by acute exposure to GDI engine exhaust in an allergic asthma murine model. Mice were sensitized with an allergen to induce airway hyperresponsiveness or treated with saline (non-allergic group. Animals were challenged for 2-h to exhaust from a laboratory GDI engine operated at conditions equivalent to a highway cruise. Exhaust was filtered to assess responses induced by the particulate and gas fractions. Short-term exposure to particulate matter from GDI engine exhaust induced upregulation of genes related to polycyclic aromatic hydrocarbon (PAH metabolism (Cyp1b1 and inflammation (TNFα in the lungs of non-allergic mice. High molecular weight PAHs dominated the particulate fraction of the exhaust, and this response was therefore likely attributable to the presence of these PAHs. The particle fraction of GDI engine exhaust further contributed to enhanced methacholine responsiveness in the central and peripheral tissues in animals with airway hyperresponsiveness. As GDI engines gain prevalence in the vehicle fleet, understanding the health impacts of their emissions becomes increasingly important.

  5. Improving of technical characteristics of launch vehicles with liquid rocket engines using active onboard de-orbiting systems

    Science.gov (United States)

    Trushlyakov, V.; Shatrov, Ya.

    2017-09-01

    In this paper, the analysis of technical requirements (TR) for the development of modern space launch vehicles (LV) with main liquid rocket engines (LRE) is fulfilled in relation to the anthropogenic impact decreasing. Factual technical characteristics on the example of a promising type of rocket ;Soyuz-2.1.v.; are analyzed. Meeting the TR in relation to anthropogenic impact decrease based on the conventional design approach and the content of the onboard system does not prove to be efficient and leads to depreciation of the initial technical characteristics obtained at the first design stage if these requirements are not included. In this concern, it is shown that the implementation of additional active onboard de-orbiting system (AODS) of worked-off stages (WS) into the onboard LV stages systems allows to meet the TR related to the LV environmental characteristics, including fire-explosion safety. In some cases, the orbital payload mass increases.

  6. The new generation of exhaust aftertreatment systems for lean fuel gasoline engines; Die neue Generation von Abgasnachbehandlungssystemen fuer magerlaufende Benzinmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Eckhoff, Stephan; Hoyer, Ruediger; Adam, Frank; Lammarck, Christian; Mueller, Wilfried [Umicore AG und Co. KG, Hanau-Wolfgang (Germany)

    2010-07-01

    Stratified gasoline direct injection engines show a great potential for the reduction of CO{sub 2} emissions and therefore improved fuel economy. The next generation of stratified gasoline engines with turbo charger and more efficient combustion are expected to have even lower exhaust temperatures compared with current series vehicle with stratified combustion. For this reason exhaust gas aftertreatment systems are required which have low light off temperatures for HC and CO during lean combustion and a high NOx-storage efficiency at low temperatures. This study shows the great improvements made over the last years for the development of new TWC and NOx-storage catalysts for the aftertreatment for lean GDI. A precious metal related cost reduction of about 40% was achieved for the new generation of aftertreatment systems. (orig.)

  7. EVALUATION OF EMISSION OF CO, NO AND NOX IN EXHAUST OF DIESEL ENGINE FUELED WITH FUEL ADDITIVED

    Directory of Open Access Journals (Sweden)

    Gilson Rodrigo de Miranda

    2011-01-01

    Full Text Available Air pollution has emerged as major global problems. In the last decade, the development of new engines, the use of different forms of treatment of exhaust gases and the increase in fuel quality were used to reduce pollutants (regulated or not. Among the various developments to reduce emissions, the use of oxygenated additives to diesel and paraffin is a quick and effective measure to reduce pollutants. In this work we studied the influence of oxygenated compounds (diethyl ether (DEE, 1-dodecanol (DOD, 2-methoxy-acetate (MEA and terc-butanol (TERC and paraffin (heptane (HEPT and n- hexadecane (CET added to diesel in order to improve the quality of CO, NO and NOx in the exhaust of diesel engine, single cylinder. The fuels used in the studies are formulations of diesel reference, here named S10, which contains low sulfur (

  8. THE EFFECT OF KARANJA OIL METHYL ESTER ON KIRLOSKAR HA394DI DIESEL ENGINE PERFORMANCE AND EXHAUST EMISSIONS

    Directory of Open Access Journals (Sweden)

    Sharanappa K Godiganur

    2010-01-01

    Full Text Available Biofuels are being investigated as potential substitutes for current high pollutant fuels obtained from the conventional sources. The primary problem associated with using straight vegetable oil as fuel in a compression ignition engine is caused by viscosity. The process of transesterifiction of vegetable oil with methyl alcohol provides a significant reduction in viscosity, thereby enhancing the physical properties of vegetable oil. The Kirloskar HA394 compression ignition, multi cylinder diesel engine does not require any modification to replace diesel by karanja methyl ester. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. The purpose of this research was to evaluate the potential of karanja oil methyl ester and its blend with diesel from 20% to 80% by volume. Engine performance and exhaust emissions were investigated and compared with the ordinary diesel fuel in a diesel engine. The experimental results show that the engine power of the mixture is closed to the values obtained from diesel fuel and the amounts of exhaust emissions are lower than those of diesel fuel. Hence, it is seen that the blend of karanja ester and diesel fuel can be used as an alternative successfully in a diesel engine without any modification and in terms of emission parameters; it is an environmental friendly fuel

  9. Experimental aerodynamic and acoustic model testing of the Variable Cycle Engine (VCE) testbed coannular exhaust nozzle system: Comprehensive data report

    Science.gov (United States)

    Nelson, D. P.; Morris, P. M.

    1980-01-01

    The component detail design drawings of the one sixth scale model of the variable cycle engine testbed demonstrator exhaust syatem tested are presented. Also provided are the basic acoustic and aerodynamic data acquired during the experimental model tests. The model drawings, an index to the acoustic data, an index to the aerodynamic data, tabulated and graphical acoustic data, and the tabulated aerodynamic data and graphs are discussed.

  10. Biological effects of chronic inhalation of coal mine dust and/or diesel engine exhaust in rodents

    International Nuclear Information System (INIS)

    Karagianes, M.T.; Palmer, R.F.; Stuart, B.O.; Zwicker, G.M.; Teats, D.

    1979-01-01

    Rats were killed at 4, 8, 16, and 20 mo after the start of exposures to inhaled high-CWP bituminous coal mine dust separately and combined with unscrubbed exhaust fumes from a diesel engine operated under load-rpm cycling. General health and hematologic parameters were normal. Lung lesions and accumulations of particulate matter increased with length and type of exposure; however, no animals have developed lung tumors or precancerous tissue changes up to 16 mo postexposure

  11. Engineering aspect of the microwave ionosphere nonlinear interaction experiment (MINIX) with a sounding rocket

    Science.gov (United States)

    Nagatomo, Makoto; Kaya, Nobuyuki; Matsumoto, Hiroshi

    The Microwave Ionosphere Nonlinear Interaction Experiment (MINIX) is a sounding rocket experiment to study possible effects of strong microwave fields in case it is used for energy transmission from the Solar Power Satellite (SPS) upon the Earth's atmosphere. Its secondary objective is to develop high power microwave technology for space use. Two rocket-borne magnetrons were used to emit 2.45 GHz microwave in order to make a simulated condition of power transmission from an SPS to a ground station. Sounding of the environment radiated by microwave was conducted by the diagnostic package onboard the daughter unit which was separated slowly from the mother unit. The main design drivers of this experiment were to build such high power equipments in a standard type of sounding rocket, to keep the cost within the budget and to perform a series of experiments without complete loss of the mission. The key technology for this experiment is a rocket-borne magnetron and high voltage converter. Location of position of the daughter unit relative to the mother unit was a difficult requirement for a spin-stabilized rocket. These problems were solved by application of such a low cost commercial products as a magnetron for microwave oven and a video tape recorder and camera.

  12. Demonstration of high temperature thermoelectric waste heat recovery from exhaust gases of a combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Trottmann, Matthias; Weidenkaff, Anke; Populoh, Sascha; Brunko, Oliver; Veziridis, Angelika; Bach, Christian; Cabalzar, Urs [Empa, Duebendorf (Switzerland)

    2011-07-01

    The energy efficiency of passenger cars becomes increasingly important due to a growing awareness in terms of climate change and shortages of resources associated with rising fuel prices. In addition to the efforts towards the optimization of the engine's internal efficiency, waste heat recovery is the main objective. In this respect, thermoelectric (TE) devices seem to be suited as heat recuperation systems. Thermoelectric generators allow for direct transformation of thermal into electrical energy. In order to thoroughly investigate this type of recovery system a TE demonstrator was mounted on the muffler of a VW Touran and tested. The waste heat of the exhaust gas was converted into electricity with a conversion rate of {proportional_to}. 3.5%. The limiting factor was the low thermal stability of the commercial modules used in this pre-study to elaborate reference values. Thermoelectric modules based on sustainable and temperature-stable materials are being developed to improve the measured values. A thermoelectric test generator with perovskite-type oxide modules was constructed confirm the function and stability at elevated temperatures. Despite all the advantages of this material class, the TE performance is still to be improved. A quantitative measure of a material's TE performance is the temperature-independent Figure of Merit ZT. ZT increases with decreasing thermal and increasing electrical conductivity. An approach to thermal conductivity reduction is nanostructuring of the material. The Ultrasonic Spray Combustion (USC) technique allows to produce powders with a grain size on the nanoscale and was tested in this study. (orig.)

  13. Copper-Multiwall Carbon Nanotubes and Copper-Diamond Composites for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, Dave L.; Smelyanskiy, Vadim; Foygel, Michael; Rape, Aaron; Singh, Jogender; Vohra, Yogesh K.; Thomas, Vinoy; Otte, Kyle G.; Li, Deyu

    2013-01-01

    This paper reports on the research effort to improve the thermal conductivity of the copper-based alloy NARloy-Z (Cu-3 wt.%Ag-0.5 wt.% Zr), the state-of-the-art alloy used to make combustion chamber liners in regeneratively-cooled liquid rocket engines, using nanotechnology. The approach was to embed high thermal conductivity multiwall carbon nanotubes (MWCNTs) and diamond (D) particles in the NARloy-Z matrix using powder metallurgy techniques. The thermal conductivity of MWCNTs and D have been reported to be 5 to 10 times that of NARloy-Z. Hence, 10 to 20 vol. % MWCNT finely dispersed in NARloy-Z matrix could nearly double the thermal conductivity, provided there is a good thermal bond between MWCNTs and copper matrix. Quantum mechanics-based modeling showed that zirconium (Zr) in NARloy-Z should form ZrC at the MWCNT-Cu interface and provide a good thermal bond. In this study, NARloy-Z powder was blended with MWCNTs in a ball mill, and the resulting mixture was consolidated under high pressure and temperature using Field Assisted Sintering Technology (FAST). Microstructural analysis showed that the MWCNTs, which were provided as tangles of MWCNTs by the manufacturer, did not detangle well during blending and formed clumps at the prior particle boundaries. The composites made form these powders showed lower thermal conductivity than the base NARloy-Z. To eliminate the observed physical agglomeration, tangled multiwall MWCNTs were separated by acid treatment and electroless plated with a thin layer of chromium to keep them separated during further processing. Separately, the thermal conductivities of MWCNTs used in this work were measured, and the results showed very low values, a major factor in the low thermal conductivity of the composite. On the other hand, D particles embedded in NARloy-Z matrix showed much improved thermal conductivity. Elemental analysis showed migration of Zr to the NARloy-Z-D interface to form ZrC, which appeared to provide a low contact

  14. Copper Multiwall Carbon Nanotubes and Copper-Diamond Composites for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, Dave L.; Smelyanskiy, Vadim; Foygel, Michael; Singh, Jogender; Rape, Aaron; Vohra, Yogesh; Thomas, Vinoy; Li, Deyu; Otte, Kyle

    2013-01-01

    This paper reports on the research effort to improve the thermal conductivity of the copper-based alloy NARloy-Z (Cu-3 wt.%Ag-0.5 wt.% Zr), the state-of-the-art alloy used to make combustion chamber liners in regeneratively-cooled liquid rocket engines, using nanotechnology. The approach was to embed high thermal conductivity multiwall carbon nanotubes (MWCNTs) and diamond (D) particles in the NARloy-Z matrix using powder metallurgy techniques. The thermal conductivity of MWCNTs and D have been reported to be 5 to 10 times that of NARloy-Z. Hence, 10 to 20 vol. % MWCNT finely dispersed in NARloy-Z matrix could nearly double the thermal conductivity, provided there is a good thermal bond between MWCNTs and copper matrix. Quantum mechanics-based modeling showed that zirconium (Zr) in NARloy-Z should form ZrC at the MWCNT-Cu interface and provide a good thermal bond. In this study, NARloy-Z powder was blended with MWCNTs in a ball mill, and the resulting mixture was consolidated under high pressure and temperature using Field Assisted Sintering Technology (FAST). Microstructural analysis showed that the MWCNTs, which were provided as tangles of MWCNTs by the manufacturer, did not detangle well during blending and formed clumps at the prior particle boundaries. The composites made form these powders showed lower thermal conductivity than the base NARloy-Z. To eliminate the observed physical agglomeration, tangled multiwall MWCNTs were separated by acid treatment and electroless plated with a thin layer of chromium to keep them separated during further processing. Separately, the thermal conductivities of MWCNTs used in this work were measured, and the results showed very low values, a major factor in the low thermal conductivity of the composite. On the other hand, D particles embedded in NARloy-Z matrix showed much improved thermal conductivity. Elemental analysis showed migration of Zr to the NARloy-Z-D interface to form ZrC, which appeared to provide a low contact

  15. Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas

    International Nuclear Information System (INIS)

    Papagiannakis, R.G.; Hountalas, D.T.

    2004-01-01

    Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high autoignition temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions

  16. Ongoing Analyses of Rocket Based Combined Cycle Engines by the Applied Fluid Dynamics Analysis Group at Marshall Space Flight Center

    Science.gov (United States)

    Ruf, Joseph H.; Holt, James B.; Canabal, Francisco

    2001-01-01

    This paper presents the status of analyses on three Rocket Based Combined Cycle (RBCC) configurations underway in the Applied Fluid Dynamics Analysis Group (TD64). TD64 is performing computational fluid dynamics (CFD) analysis on a Penn State RBCC test rig, the proposed Draco axisymmetric RBCC engine and the Trailblazer engine. The intent of the analysis on the Penn State test rig is to benchmark the Finite Difference Navier Stokes (FDNS) code for ejector mode fluid dynamics. The Draco analysis was a trade study to determine the ejector mode performance as a function of three engine design variables. The Trailblazer analysis is to evaluate the nozzle performance in scramjet mode. Results to date of each analysis are presented.

  17. Improvement of the thermal and mechanical flow characteristics in the exhaust system of piston engine through the use of ejection effect

    Science.gov (United States)

    Plotnikov, L. V.; Zhilkin, B. P.; Brodov, Yu M.

    2017-11-01

    The results of experimental research of gas dynamics and heat transfer in the exhaust process in piston internal combustion engines are presented. Studies were conducted on full-scale models of piston engine in the conditions of unsteady gas-dynamic (pulsating flows). Dependences of the instantaneous flow speed and the local heat transfer coefficient from the crankshaft rotation angle in the exhaust pipe are presented in the article. Also, the flow characteristics of the exhaust gases through the exhaust systems of various configurations are analyzed. It is shown that installation of the ejector in the exhaust system lead to a stabilization of the flow and allows to improve cleaning of the cylinder from exhaust gases and to optimize the thermal state of the exhaust pipes. Experimental studies were complemented by numerical simulation of the working process of the DM-21 diesel engine (production of “Ural diesel-motor plant”). The object of modeling was the eight-cylinder diesel with turbocharger. The simulation was performed taking into account the processes nonstationarity in the intake and exhaust pipes for the various configurations of exhaust systems (with and without ejector). Numerical simulation of the working process of diesel was performed in ACTUS software (ABB Turbo Systems). The simulation results confirmed the stabilization of the flow due to the use of the ejection effect in the exhaust system of a diesel engine. The use of ejection in the exhaust system of the DM-21 diesel leads to improvement of cleaning cylinders up to 10 %, reduces the specific fuel consumption on average by 1 %.

  18. Fast spatially resolved exhaust gas recirculation (EGR) distribution measurements in an internal combustion engine using absorption spectroscopy.

    Science.gov (United States)

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2015-09-01

    Exhaust gas recirculation (EGR) in internal combustion engines is an effective method of reducing NOx emissions while improving efficiency. However, insufficient mixing between fresh air and exhaust gas can lead to cycle-to-cycle and cylinder-to-cylinder non-uniform charge gas mixtures of a multi-cylinder engine, which can in turn reduce engine performance and efficiency. A sensor packaged into a compact probe was designed, built and applied to measure spatiotemporal EGR distributions in the intake manifold of an operating engine. The probe promotes the development of more efficient and higher-performance engines by resolving high-speed in situ CO2 concentration at various locations in the intake manifold. The study employed mid-infrared light sources tuned to an absorption band of CO2 near 4.3 μm, an industry standard species for determining EGR fraction. The calibrated probe was used to map spatial EGR distributions in an intake manifold with high accuracy and monitor cycle-resolved cylinder-specific EGR fluctuations at a rate of up to 1 kHz.

  19. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    OpenAIRE

    Juan Miguel Mantilla; Camilo Andrés Falla; Jorge Arturo Gómez

    2010-01-01

    Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes) which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in re...

  20. Internal combustion engine exhaust pipe flow simulation. Part I: theoretical aspects

    OpenAIRE

    Juan Miguel Mantilla; Camilo Andrés Falla; Jorge Arturo Gómez

    2009-01-01

    Unsteady gas flow theory can be used for simulating a spark ignition internal combustion engine’s exhaust system, using pressure waves. The method explained here is based on the discretization of interpolated spaces (called meshes) which are located throughout the whole length of the exhaust pipe, irrespective of its form or size. The most important aspects of this theory are theoretically explored, such as pressure wave movement and shock and their application to cases found in real engines’...

  1. An investigation of the treatment of particulate matter from gasoline engine exhaust using non-thermal plasma

    International Nuclear Information System (INIS)

    Ye Dan; Gao Dengshan; Yu Gang; Shen Xianglin; Gu Fan

    2005-01-01

    A plasma reactor with catalysts was used to treat exhaust gas from a gasoline engine in order to decrease particulate matter (PM) emissions. The effect of non-thermal plasma (NTP) of the dielectric discharges on the removal of PM from the exhaust gas was investigated experimentally. The removal efficiency of PM was based on the concentration difference in PM for particle diameters ranging from 0.3 to 5.0 μm as measured by a particle counter. Several factors affecting PM conversion, including the density of plasma energy, reaction temperature, flow rate of exhaust gas, were investigated in the experiment. The results indicate that PM removal efficiency ranged approximately from 25 to 57% and increased with increasing energy input in the reactor, reaction temperature and residence time of the exhaust gas in the reactor. Enhanced removal of the PM was achieved by filling the discharge gap of the reactor with Cu-ZSM-5 catalyst pellets. In addition, the removal of unburned hydrocarbons was studied. Finally, available approaches for PM conversion were analyzed involving the interactions between discharge and catalytic reactions

  2. Determination of the Flow Field in the Propellant Tank of a Rocket Engine on Completion of the Mission

    Science.gov (United States)

    Fedorov, A. V.; Bedarev, I. A.; Lavruk, S. A.; Trushlyakov, V. I.; Kudentsov, V. Yu.

    2018-03-01

    In the present work, a method of mathematical simulation is employed to describe processes occurring in the specimens of new equipment and using the remaining propellant in rocket-engine tanks. Within the framework of certain turbulence models, the authors perform a calculation of the flow field in the volume of the tank of the launch-vehicle stage when a hot gas jet is injected into it. A vortex flow structure is revealed; the characteristics of heat transfer for different angles of injection of the jet are determined. The obtained correlation Nu = Nu(Re) satisfactorily describes experimental data.

  3. Validated analytical modeling of diesel engine regulated exhaust CO emission rate

    Directory of Open Access Journals (Sweden)

    Waleed F Faris

    2016-06-01

    Full Text Available Albeit vehicle analytical models are often favorable for explainable mathematical trends, no analytical model has been developed of the regulated diesel exhaust CO emission rate for trucks yet. This research unprecedentedly develops and validates for trucks a model of the steady speed regulated diesel exhaust CO emission rate analytically. It has been found that the steady speed–based CO exhaust emission rate is based on (1 CO2 dissociation, (2 the water–gas shift reaction, and (3 the incomplete combustion of hydrocarbon. It has been found as well that the steady speed–based CO exhaust emission rate based on CO2 dissociation is considerably less than the rate that is based on the water–gas shift reaction. It has also been found that the steady speed–based CO exhaust emission rate based on the water–gas shift reaction is the dominant source of CO exhaust emission. The study shows that the average percentage of deviation of the steady speed–based simulated results from the corresponding field data is 1.7% for all freeway cycles with 99% coefficient of determination at the confidence level of 95%. This deviation of the simulated results from field data outperforms its counterpart of widely recognized models such as the comprehensive modal emissions model and VT-Micro for all freeway cycles.

  4. Engineering task plan for rotary mode core sampling exhausters CAM high radiation interlock

    International Nuclear Information System (INIS)

    BOGER, R.M.

    1999-01-01

    The Rotary Mode Core Sampling (RMCS) system is primarily made up of the Rotary Mode Core Sample Trucks (RMCST) and the RMCS Exhausters. During RMCS operations an Exhauster is connected to a tank riser and withdraws gases from the tank dome vapor space at approximately 200 Standard Cubic Feet per Minute (SCFM). The gases are passed through two High Efficiency Particulate Air (HEPA) filters before passing out the exhaust stack to the atmosphere. A Continuous Air Monitor (CAM) monitors the exhaust gases in the exhaust stack for beta particle and gamma radiation. The CAM has a high radiation alarm output and a detector fail alarm output. The CAM alarms are currently connected to the data logger only. The CAM alarms require operator response per procedure LMHC 1998 but no automatic functions are initiated by the CAM alarms. Currently, there are three events that can cause an automatic shut down of the Exhauster. These are, Low Tank Pressure, Highnow Stack Flow and High HEPA Filter Differential Pressure (DP)

  5. UV Absorption Measurements of Nitric Oxide Compared to Probe Sampling Data for Measurements in a Turbine Engine Exhaust at Simulated Altitude Conditions

    National Research Council Canada - National Science Library

    Howard, R

    1997-01-01

    Nitric oxide measurements were conducted in the exhaust of a turbofan engine at simulated altitude conditions in a ground-level test cell using both optical nonintrusive and conventional gas sampling techniques...

  6. Specific emissions analysis for a combustion engine in dynamometer operation in relation to the thermal state of the exhaust gas aftertreatment systems in a modified NRSC test

    Directory of Open Access Journals (Sweden)

    Merkisz Jerzy

    2017-01-01

    Full Text Available Exhaust gas aftertreatment systems have been present in motor vehicles for decades and have contributed to reducing their impact on the environment and people. Most of them for oxidation or reduction of harmful emissions of particulates and fumes require a certain temperature to be reached that changes with the exhaust temperature, i.e. the points of engine operation. The article describes the effect of oxidation reactor and particulate filter temperatures on specific emissions of gaseous compounds and particulate matter during the modified NRSC engine test. Before the first measurement cycle, the engine was idling, before the second measurement cycle, the exhaust system was heated with exhaust gases at full engine load until passive regeneration of the particle filter occurred (noticeable decrease in instantaneous particle concentration.

  7. Effect of Exhaust Gas Recirculation on Performance of a Diesel Engine Fueled with Waste Plastic Oil / Diesel Blends

    Directory of Open Access Journals (Sweden)

    Punitharani K.

    2017-11-01

    Full Text Available NOx emission is one of the major sources for health issues, acid rain and global warming. Diesel engine vehicles are the major sources for NOx emissions. Hence there is a need to reduce the emissions from the engines by identifying suitable techniques or by means of alternate fuels. The present investigation deals with the effect of Exhaust Gas Recirculation (EGR on 4S, single cylinder, DI diesel engine using plastic oil/Diesel blends P10 (10% plastic oil & 90% diesel in volume, P20 and P30 at various EGR rates. Plastic oil blends were able to operate in diesel engines without any modifications and the results showed that P20 blend had the least NOx emission quantity.

  8. 40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.

    Science.gov (United States)

    2010-07-01

    ... exhaust duct excludes the length of pipe representative of the vehicle exhaust pipe) shall be minimized... exhaust manifold, immediately after exhaust aftertreatment systems, or after a length of pipe representative of the vehicle exhaust pipe; or (iv) Partial dilution of the exhaust gas prior to entering the...

  9. Rockets: Educator's Guide with Activities in Science, Technology, Engineering and Mathematics

    Science.gov (United States)

    Shearer, Deborah A.; Vogt, Gregory L.

    2008-01-01

    This guide provides teachers and students many opportunities. Chapters within the guide present the history of rocketry, National Aeronautics and Space Administration's (NASA's) 21st Century Space Exploration Policy, rocketry principles, and practical rocketry. These topics lay the foundation for what follows--a wealth of dynamic rocket science…

  10. A review of findings of a study of rocket based combined cycle engines applied to extensively axisymmetric single stage to orbit vehicles

    Science.gov (United States)

    Foster, Richard W.

    1992-01-01

    Extensively axisymmetric and non-axisymmetric Single Stage To Orbit (SSTO) vehicles are considered. The information is presented in viewgraph form and the following topics are presented: payload comparisons; payload as a percent of dry weight - a system hardware cost indicator; life cycle cost estimations; operations and support costs estimation; selected engine type; and rocket engine specific impulse calculation.

  11. Calculated concentrations of any radionuclide deposited on the ground by release from underground nuclear detonations, tests of nuclear rockets, and tests of nuclear ramjet engines

    International Nuclear Information System (INIS)

    Hicks, H.G.

    1981-11-01

    This report presents calculated gamma radiation exposure rates and ground deposition of related radionuclides resulting from three types of event that deposited detectable radioactivity outside the Nevada Test Site complex, namely, underground nuclear detonations, tests of nuclear rocket engines and tests of nuclear ramjet engines

  12. Affordable Development and Demonstration of a Small Nuclear Thermal Rocket (NTR) Engine and Stage: How Small Is Big Enough?

    Science.gov (United States)

    Borowski, Stanley K.; Sefcik, Robert J.; Fittje, James E.; McCurdy, David R.; Qualls, Arthur L.; Schnitzler, Bruce G.; Werner, James E.; Weitzberg, Abraham; Joyner, Claude R.

    2016-01-01

    The Nuclear Thermal Rocket (NTR) derives its energy from fission of uranium-235 atoms contained within fuel elements that comprise the engine's reactor core. It generates high thrust and has a specific impulse potential of approximately 900 specific impulse - a 100 percent increase over today's best chemical rockets. The Nuclear Thermal Propulsion (NTP) project, funded by NASA's Advanced Exploration Systems (AES) program, includes five key task activities: (1) Recapture, demonstration, and validation of heritage graphite composite (GC) fuel (selected as the Lead Fuel option); (2) Engine Conceptual Design; (3) Operating Requirements Definition; (4) Identification of Affordable Options for Ground Testing; and (5) Formulation of an Affordable Development Strategy. During fiscal year (FY) 2014, a preliminary Design Development Test and Evaluation (DDT&E) plan and schedule for NTP development was outlined by the NASA Glenn Research Center (GRC), Department of Energy (DOE) and industry that involved significant system-level demonstration projects that included Ground Technology Demonstration (GTD) tests at the Nevada National Security Site (NNSS), followed by a Flight Technology Demonstration (FTD) mission. To reduce cost for the GTD tests and FTD mission, small NTR engines, in either the 7.5 or 16.5 kilopound-force thrust class, were considered. Both engine options used GC fuel and a common fuel element (FE) design. The small approximately 7.5 kilopound-force criticality-limited engine produces approximately157 thermal megawatts and its core is configured with parallel rows of hexagonal-shaped FEs and tie tubes (TTs) with a FE to TT ratio of approximately 1:1. The larger approximately 16.5 kilopound-force Small Nuclear Rocket Engine (SNRE), developed by Los Alamos National Laboratory (LANL) at the end of the Rover program, produces approximately 367 thermal megawatts and has a FE to TT ratio of approximately 2:1. Although both engines use a common 35-inch (approximately

  13. Analysis of the Impact of Early Exhaust Valve Opening and Cylinder Deactivation on Aftertreatment Thermal Management and Efficiency for Compression Ignition Engines

    OpenAIRE

    Roberts, Leighton Edward

    2014-01-01

    In order to meet strict emissions regulations, engine manufacturers have implemented aftertreatment technologies which reduce the tailpipe emissions from diesel engines. The effectiveness of most of these systems is limited when exhaust temperatures are low (usually below 200°C to 250°C). This is a problem for extended low load operation, such as idling and during cold start. Use of variable valve actuation, including early exhaust valve opening (EEVO) and cylinder deactivation (CDA), has bee...

  14. Effects of valve timing, valve lift and exhaust backpressure on performance and gas exchanging of a two-stroke GDI engine with overhead valves

    International Nuclear Information System (INIS)

    Dalla Nora, Macklini; Lanzanova, Thompson Diórdinis Metzka; Zhao, Hua

    2016-01-01

    Highlights: • Two-stroke operation was achieved in a four-valve direct injection gasoline engine. • Shorter valve opening durations improved torque at lower engine speeds. • The longer the valve opening duration, the lower was the air trapping efficiency. • Higher exhaust backpressure and lower valve lift reduced the compressor work. - Abstract: The current demand for fuel efficient and lightweight powertrains, particularly for application in downsized and hybrid electric vehicles, has renewed the interest in two-stroke engines. In this framework, an overhead four-valve spark-ignition gasoline engine was modified to run in the two-stroke cycle. The scavenging process took place during a long valve overlap period around bottom dead centre at each crankshaft revolution. Boosted intake air was externally supplied at a constant pressure and gasoline was directly injected into the cylinder after valve closure. Intake and exhaust valve timings and lifts were independently varied through an electrohydraulic valve train, so their effects on engine performance and gas exchanging were investigated at 800 rpm and 2000 rpm. Different exhaust backpressures were also evaluated by means of exhaust throttling. Air trapping efficiency, charging efficiency and scavenge ratio were calculated based on air and fuel flow rates, and exhaust oxygen concentration at fuel rich conditions. The results indicated that longer intake and exhaust valve opening durations increased the charge purity and hence torque at higher engine speeds. At lower speeds, although, shorter valve opening durations increased air trapping efficiency and reduced the estimated supercharger power consumption due to lower air short-circuiting. A strong correlation was found between torque and charging efficiency, while air trapping efficiency was more associated to exhaust valve opening duration. The application of exhaust backpressure, as well as lower intake/exhaust valve lifts, made it possible to increase

  15. Two-Dimensional Motions of Rockets

    Science.gov (United States)

    Kang, Yoonhwan; Bae, Saebyok

    2007-01-01

    We analyse the two-dimensional motions of the rockets for various types of rocket thrusts, the air friction and the gravitation by using a suitable representation of the rocket equation and the numerical calculation. The slope shapes of the rocket trajectories are discussed for the three types of rocket engines. Unlike the projectile motions, the…

  16. Effect of Exhaust Gas Recirculation (EGR on the Performance Characteristics of a Direct Injection Multi Cylinders Diesel Engine

    Directory of Open Access Journals (Sweden)

    Khalil Ibrahim Abaas

    2016-07-01

    Full Text Available Owing  to  the  energy  crisis  and  pollution  problems  of  today  investigations  have  concentrated  on decreasing  fuel  consumption  and  on  lowering  the  concentration  of  toxic  components  in  combustion products by using exhaust gas after treatments methods like PM filters and EGR for NOx reduction. In this study, the combustion characteristics of diesel fuel were compared with that pr oduced from adding EGR at several percentages to air manifold. The tests were performed in a four-cylinder direct injection (DI diesel engine at constant engine speed (1500 rpm and variable loads (from no load to 86 kN/m2, the tests were repeated with constant load (77 kN/m2 and variable engine speeds (from 1250 to 3000 rpm.The experimental results showed that adding EGR to diesel engine provided significant reductions in brake power (bp, brake thermal efficiency and exhaust gas temperatures, while high increments in brake specific  fuel  consumption  (bsfc.  High  EGR  percentage  (as  30%  in  this  article  caused  an  11.7% reduction  in  brake  thermal  efficiency,  26.38%  reduction  in  exhaust  gas  temperatures  and  12.28%  in volumetric efficiency at full load conditions.

  17. Diesel engine exhaust accelerates plaque formation in a mouse model of Alzheimer's disease.

    Science.gov (United States)

    Hullmann, Maja; Albrecht, Catrin; van Berlo, Damiën; Gerlofs-Nijland, Miriam E; Wahle, Tina; Boots, Agnes W; Krutmann, Jean; Cassee, Flemming R; Bayer, Thomas A; Schins, Roel P F

    2017-08-30

    Increasing evidence from toxicological and epidemiological studies indicates that the central nervous system is an important target for ambient air pollutants. We have investigated whether long-term inhalation exposure to diesel engine exhaust (DEE), a dominant contributor to particulate air pollution in urban environments, can aggravate Alzheimer's Disease (AD)-like effects in female 5X Familial AD (5XFAD) mice and their wild-type female littermates. Following 3 and 13 weeks exposures to diluted DEE (0.95 mg/m 3 , 6 h/day, 5 days/week) or clean air (controls) behaviour tests were performed and amyloid-β (Aβ) plaque formation, pulmonary histopathology and systemic inflammation were evaluated. In a string suspension task, assessing for grip strength and motor coordination, 13 weeks exposed 5XFAD mice performed significantly less than the 5XFAD controls. Spatial working memory deficits, assessed by Y-maze and X-maze tasks, were not observed in association with the DEE exposures. Brains of the 3 weeks DEE-exposed 5XFAD mice showed significantly higher cortical Aβ plaque load and higher whole brain homogenate Aβ42 levels than the clean air-exposed 5XFAD littermate controls. After the 13 weeks exposures, with increasing age and progression of the AD-phenotype of the 5XFAD mice, DEE-related differences in amyloid pathology were no longer present. Immunohistochemical evaluation of lungs of the mice revealed no obvious genetic background-related differences in tissue structure, and the DEE exposure did not cause histopathological changes in the mice of both backgrounds. Luminex analysis of plasma cytokines demonstrated absence of sustained systemic inflammation upon DEE exposure. Inhalation exposure to DEE causes accelerated plaque formation and motor function impairment in 5XFAD transgenic mice. Our study provides further support that the brain is a relevant target for the effects of inhaled DEE and suggests that long-term exposure to this ubiquitous air

  18. Experimental study on performance and exhaust emissions of a diesel engine fuelled with Ceiba pentandra biodiesel blends

    International Nuclear Information System (INIS)

    Silitonga, A.S.; Masjuki, H.H.; Mahlia, T.M.I.; Ong, Hwai Chyuan; Chong, W.T.

    2013-01-01

    Highlights: • Ceiba pentandra biodiesel was prepared by two-step transesterification. • The main FAC of C. pentandra is 18.54% of malvalic acid. • Engine performance and emission are conducted for CPME and its blends. • The CPB10 gives the best engine performance at 1900 rpm. • The CO, HC and smoke opacity were lower for all biodiesel blends. - Abstract: Nowadays, production of biodiesel from non-edible feedstock is gaining more attention than edible oil to replace diesel fuel. Thus, Ceiba pentandra is chosen as a potential biodiesel feedstock for the present investigations based on the availability in Indonesia and Malaysia. C. pentandra methyl ester was prepared by two-step acid esterification (H 2 SO 4 ) and base transesterification (NaOH) process. The purpose of this study is to examine the engine performance and emission characteristic of C. pentandra biodiesel diesel blends in internal combustion. Besides, the detailed properties of C. pentandra biodiesel, biodiesel diesel blends and diesel were measured and evaluated. After that, the biodiesel diesel blends (10%, 20%, 30% and 50%) were used to conduct engine performance and exhaust emission characteristic at different engine speeds. The experimental results showed that CPB10 blend give the best results on engine performance such as engine torque and power at 1900 rpm with full throttle condition. Besides, the brake specific fuel consumption at maximum torque (161 g/kW h) for CPB10 is higher about 22.98% relative to diesel fuel (198 g/kW h). This is shown that the lower biodiesel diesel blends ratio will increase the performance and reduce the fuel consumption. Moreover, the exhaust emissions showed that CO, HC and smoke opacity were reduced for all biodiesel diesel blends. However, NO x and CO 2 were increased compared to petrol diesel. Overall, the results proved that C. pentandra biodiesel is a suitable alternative and substitute fuel to diesel

  19. Toxicity of Exhaust Gases and Particles from IC-Engines -- International Activities Survey (EngToxIn)

    Energy Technology Data Exchange (ETDEWEB)

    Czerwinski, J [University for Applied Sciences, Biel-Bienne (Switzerland)

    2011-09-15

    Exhaust gases from engines, as well as from other combustion -- and industrial processes contain different gaseous, semi volatile and solid compounds which are toxic. Some of these compounds are not regarded by the respective legislations; some new substances may appear, due to the progressing technical developments and new systems of exhaust gas aftertreatment. The toxical effects of exhaust gases as whole aerosols (i.e. all gaseous components together with particle matter and nanoparticles) can be investigated in a global way, by exposing the living cells, or cell cultures to the aerosol, which means a simultaneous superposition of all toxic effects from all active components. On several places researchers showed, that this method offers more objective results of validation of toxicity, than other methods used up to date. It also enables a relatively quick insight in the toxic effects with consideration of all superimposed influences of the aerosol. This new methodology can be applied for all kinds of emission sources. It bears potentials of giving new contributions to the present state of knowledge in this domain and can in some cases lead to a change of paradigma. The present report gives short information about the activities concerning the research on toxicity of exhaust gases from IC-engines in different countries. It also gives some ideas about research of information sources. It can be stated that there are worldwide a lot of activities concerning health effects. They have different objectives, different approaches and methodologies and rarely the results can be directly compared to each other. Nevertheless there also are some common lines and with appropriate efforts there are possible ways to establish the harmonised biological test procedures.

  20. Comparisons of system benefits and thermo-economics for exhaust energy recovery applied on a heavy-duty diesel engine and a light-duty vehicle gasoline engine

    International Nuclear Information System (INIS)

    Wang, Tianyou; Zhang, Yajun; Zhang, Jie; Peng, Zhijun; Shu, Gequn

    2014-01-01

    Highlights: • Comparisons of exhaust energy recovery are launched between two types of engine. • System performances are analyzed in terms of benefits and thermo-economics. • Diesel engine system presents superior to gasoline type in economic applicability. • Only diesel engine system using water under full load meets the economic demand. - Abstract: Exhaust energy recovery system (EERS) based on Rankine cycle (RC) in internal combustion engines have been studied mainly on heavy-duty diesel engines (D) and light-duty vehicle gasoline engines (G), however, little information available on systematical comparisons and evaluations between the two applications, which is a particularly necessary summary for clarifying the differences. In this paper, the two particular systems are compared quantitatively using water, R141b, R123 and R245fa as working fluids. The influences of evaporating pressure, engine type and load on the system performances are analyzed with multi-objectives, including the thermal efficiency improvement, the reduced CO 2 emission, the total heat transfer area per net power output (APP), the electricity production cost (EPC) and the payback period (PBP). The results reveal that higher pressure and engine load would be attractive for better performances. R141b shows the best performances in system benefits for the D-EERS, while water exhibits the largest contributions in the G-EERS. Besides, water performs the best thermo-economics, and R245fa serves as the most uneconomical fluid. The D-EERS presents superior to the G-EERS in the economic applicability as well as much more CO 2 emission reductions, although with slightly lower thermal efficiency improvement, and only the D-EERS with water under the full load meets the economic demand. Therefore the EERS based on RC serve more applicable on the heavy-duty diesel engine, while it might be feasible for the light-duty vehicle gasoline engine as the state-of-the art technologies are developed in the

  1. THE POSSIBILITY OF USING LASER-ULTRASOUND TO MONITOR THE QUALITY SOLDERED CONNECTIONS CHAMBERS OF LIQUID ROCKET ENGINES

    Directory of Open Access Journals (Sweden)

    N. V. Astredinova

    2014-01-01

    Full Text Available During the manufacturing process to the design of modern liquid rocket engines are presented important requirements, such as minimum weight, maximum stiffness and strength of nodes, maximum service life in operation, high reliability and quality of soldered and welded seams. Due to the high quality requirements soldered connections and the specific design of the nozzle, it became necessary in the development and testing of a new non-conventional non-destructive testing method – laser-ultrasound diagnosis. In accordance with regulatory guidelines, quality control soldered connections is allowed to use an acoustic kind of control methods of the reflected light, transmitted light, resonant, free vibration and acoustic emission. Attempts to use traditional methods of non-destructive testing did not lead to positive results. This is due primarily to the size of typical solder joint defects, as well as the structural features of the rocket engine, the data structure is not controllable. In connection with this, a new method that provides quality control soldered connections cameras LRE based on the thermo generation of ultrasound. Methods of ultrasonic flaw detection of photoacoustic effect, in most cases, have a number of advantages over methods that use standard (traditional piezo transducers. In the course of studies have found that the sensitivity of the laser-ultrasonic method and flaw detector UDL-2M can detect lack of adhesion in the solder joints on the upper edges of the nozzle in the sub-header area of the site.

  2. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    This paper describes the process development for fabricating a high thermal conductivity NARloy-Z-Diamond composite (NARloy-Z-D) combustion chamber liner for application in advanced rocket engines. The fabrication process is challenging and this paper presents some details of these challenges and approaches used to address them. Prior research conducted at NASA-MSFC and Penn State had shown that NARloy-Z-40%D composite material has significantly higher thermal conductivity than the state of the art NARloy-Z alloy. Furthermore, NARloy-Z-40 %D is much lighter than NARloy-Z. These attributes help to improve the performance of the advanced rocket engines. Increased thermal conductivity will directly translate into increased turbopump power, increased chamber pressure for improved thrust and specific impulse. Early work on NARloy-Z-D composites used the Field Assisted Sintering Technology (FAST, Ref. 1, 2) for fabricating discs. NARloy-Z-D composites containing 10, 20 and 40vol% of high thermal conductivity diamond powder were investigated. Thermal conductivity (TC) data. TC increased with increasing diamond content and showed 50% improvement over pure copper at 40vol% diamond. This composition was selected for fabricating the combustion chamber liner using the FAST technique.

  3. The Primary Experiments of an Analysis of Pareto Solutions for Conceptual Design Optimization Problem of Hybrid Rocket Engine

    Science.gov (United States)

    Kudo, Fumiya; Yoshikawa, Tomohiro; Furuhashi, Takeshi

    Recentry, Multi-objective Genetic Algorithm, which is the application of Genetic Algorithm to Multi-objective Optimization Problems is focused on in the engineering design field. In this field, the analysis of design variables in the acquired Pareto solutions, which gives the designers useful knowledge in the applied problem, is important as well as the acquisition of advanced solutions. This paper proposes a new visualization method using Isomap which visualizes the geometric distances of solutions in the design variable space considering their distances in the objective space. The proposed method enables a user to analyze the design variables of the acquired solutions considering their relationship in the objective space. This paper applies the proposed method to the conceptual design optimization problem of hybrid rocket engine and studies the effectiveness of the proposed method.

  4. Modeling Macro- and Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes

    Science.gov (United States)

    Menon, Suresh

    1998-01-01

    Simulation of turbulent mixing and chemical processes in the near-field plume and plume-vortex regimes has been successfully carried out recently using a reduced gas phase kinetics mechanism which substantially decreased the computational cost. A detailed mechanism including gas phase HOx, NOx, and SOx chemistry between the aircraft exhaust and the ambient air in near-field aircraft plumes is compiled. A reduced mechanism capturing the major chemical pathways is developed. Predictions by the reduced mechanism are found to be in good agreement with those by the detailed mechanism. With the reduced chemistry, the computer CPU time is saved by a factor of more than 3.5 for the near-field plume modeling. Distributions of major chemical species are obtained and analyzed. The computed sensitivities of major species with respect to reaction step are deduced for identification of the dominant gas phase kinetic reaction pathways in the jet plume. Both the near field plume and the plume-vortex regimes were investigated using advanced mixing models. In the near field, a stand-alone mixing model was used to investigate the impact of turbulent mixing on the micro- and macro-scale mixing processes using a reduced reaction kinetics model. The plume-vortex regime was simulated using a large-eddy simulation model. Vortex plume behind Boeing 737 and 747 aircraft was simulated along with relevant kinetics. Many features of the computed flow field show reasonable agreement with data. The entrainment of the engine plumes into the wing tip vortices and also the partial detrainment of the plume were numerically captured. The impact of fluid mechanics on the chemical processes was also studied. Results show that there are significant differences between spatial and temporal simulations especially in the predicted SO3 concentrations. This has important implications for the prediction of sulfuric acid aerosols in the wake and may partly explain the discrepancy between past numerical studies

  5. Investigation of nanoparticle additives to biodiesel for improvement of the performance of the exhaust emissions in a compression ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Ozgur, Tayfun; Ozcanli, Mustafa; Aydin, Kadir [Cukurova University Engineering Architecture Faculty Mechanical Engineering Department (Turkey)], E-mail: tozgur@cu.edu.tr, email: ozcanli@cu.edu.tr, email: kdraydin@cu.edu.tr

    2011-07-01

    Reformulated diesel fuels have been studied recently to achieve substantial reductions in harmful emissions by varying the physicochemical properties and combustion characteristics of the hydrocarbon fuel. This article investigates the effects of the addition of oxygen containing nanoparticle additives to biodiesel on fuel properties, engine performance and exhaust emission characteristics. Due to the addition of magnesium oxide (MgO) and silicon oxide (SiO2) nanoparticles at different dosing levels (25 and 50 ppm), it was observed that the density of biodiesel fuel does not show significant variation but the viscosity of biodiesel fuel was found to decrease. As a result of this study, optimum additive and addition dosage was determined as 25 ppm MgO and 25 ppm SiO2, engine emission values namely nitrogen oxides (NOx) and carbon monoxide (CO) were decreased and engine performance values slightly increased with the addition of nanoparticle additives at low extra cost of the biodiesel.

  6. Equipment to reduce the emission of noxious components in the exhaust gas of an internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Tatsutomi, Y; Inoue, H

    1976-10-21

    The invention concerns an arrangement for the reduction of emission of noxious components in exhaust gas of an internal combustion engine with automatic drive. According to the invention, there is a further switch in parallel with the usual kickdown switch, which is actuated by a temperature sensor and/or choke. If the operating temperature of the engine is below a certain value, or if the choke is pulled out, then the switch is closed. This has the effect that the downstream valve is brought into the same position as that in which the closed kickdown switch would place it. The automatic drive therefore takes up that position, independently of the position of the accelerator pedal, which it would normally occupy only with the accelerator pedal fully pressed down. This guarantees that the engine is always kept at high speed during the hot running phase, which reduces the portion of the noxious gas components emitted.

  7. Some Calculated Research Results of the Working Process Parameters of the Low Thrust Rocket Engine Operating on Gaseous Oxygen-Hydrogen Fuel

    Science.gov (United States)

    Ryzhkov, V.; Morozov, I.

    2018-01-01

    The paper presents the calculating results of the combustion products parameters in the tract of the low thrust rocket engine with thrust P ∼ 100 N. The article contains the following data: streamlines, distribution of total temperature parameter in the longitudinal section of the engine chamber, static temperature distribution in the cross section of the engine chamber, velocity distribution of the combustion products in the outlet section of the engine nozzle, static temperature near the inner wall of the engine. The presented parameters allow to estimate the efficiency of the mixture formation processes, flow of combustion products in the engine chamber and to estimate the thermal state of the structure.

  8. Combustion and exhaust emission characteristics of a compression ignition engine using liquefied petroleum gas-Diesel blended fuel

    International Nuclear Information System (INIS)

    Qi, D.H.; Bian, Y.ZH.; Ma, ZH.Y.; Zhang, CH.H.; Liu, SH.Q.

    2007-01-01

    Towards the effort of reducing pollutant emissions, especially smoke and nitrogen oxides, from direct injection (DI) Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. The use of liquefied petroleum gas (LPG) as an alternative fuel is a promising solution. The potential benefits of using LPG in Diesel engines are both economical and environmental. The high auto-ignition temperature of LPG is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under LPG-Diesel blended fuel conditions, using LPG-Diesel blended fuels with various blended rates (0%, 10%, 20%, 30%, 40%). Comparative results are given for various engine speeds and loads for conventional Diesel and blended fuels, revealing the effect of blended fuel combustion on engine performance and exhaust emissions

  9. Scaled Rocket Testing in Hypersonic Flow

    Science.gov (United States)

    Dufrene, Aaron; MacLean, Matthew; Carr, Zakary; Parker, Ron; Holden, Michael; Mehta, Manish

    2015-01-01

    NASA's Space Launch System (SLS) uses four clustered liquid rocket engines along with two solid rocket boosters. The interaction between all six rocket exhaust plumes will produce a complex and severe thermal environment in the base of the vehicle. This work focuses on a recent 2% scale, hot-fire SLS base heating test. These base heating tests are short-duration tests executed with chamber pressures near the full-scale values with gaseous hydrogen/oxygen engines and RSRMV analogous solid propellant motors. The LENS II shock tunnel/Ludwieg tube tunnel was used at or near flight duplicated conditions up to Mach 5. Model development was strongly based on the Space Shuttle base heating tests with several improvements including doubling of the maximum chamber pressures and duplication of freestream conditions. Detailed base heating results are outside of the scope of the current work, rather test methodology and techniques are presented along with broader applicability toward scaled rocket testing in supersonic and hypersonic flow.

  10. Modeling of Uneven Flow and Electromagnetic Field Parameters in the Combustion Chamber of Liquid Rocket Engine with a Near-wall Layer Available

    Directory of Open Access Journals (Sweden)

    A. V. Rudinskii

    2015-01-01

    Full Text Available The paper concerns modeling of an uneven flow and electromagnetic field parameters in the combustion chamber of the liquid rocket engine with a near-wall layer available.The research objective was to evaluate quantitatively influence of changing model chamber mode of the liquid rocket engine on the electro-physical characteristics of the hydrocarbon fuel combustion by-products.The main method of research was based on development of a final element model of the flowing path of the rocket engine chamber and its adaptation to the boundary conditions.The paper presents a developed two-dimensional non-stationary mathematical model of electro-physical processes in the liquid rocket engine chamber using hydrocarbon fuel. The model takes into consideration the features of a gas-dynamic contour of the engine chamber and property of thermo-gas-dynamic characteristics of the ionized products of combustion of hydrocarbonic fuel. Distributions of magnetic field intensity and electric conductivity received and analyzed taking into account a low-temperature near-wall layer. Special attention is paid to comparison of obtained calculation values of the electric current, which is taken out from intrachamber space of the engine with earlier published data of other authors.

  11. Study on waste heat recovery from exhaust gas spark ignition (S.I. engine using steam turbine mechanism

    Directory of Open Access Journals (Sweden)

    Talib Kamarulhelmy

    2017-01-01

    Full Text Available The issue of global warming has pushed the effort of researchers not only to find alternative renewable energy, but also to improve the machine’s energy efficiency. This includes the utilization of waste energy into ‘useful energy’. For a vehicle using internal combustion engine (ICE, the waste energy produce by exhaust gas can be utilize to ‘useful energy’ up to 34%. The energy from the automotive exhaust can be harness by implementing heat pipe heat exchanger in the automotive system. In order to maximize the amount of waste energy that can be turned to ‘useful energy’, the used of appropriate fluid in the heat exchanger is important. In this study, the fluid used is water, thus converting the fluid into steam and thus drive the turbine that coupling with generator. The paper will explore the performance of a naturally aspirated spark ignition (S.I. engine equipped with waste heat recovery mechanism (WHRM that used water as the heat absorption medium. The experimental and simulation test suggest that the concept is thermodynamically feasible and could significantly enhance the system performance depending on the load applied to the engine.

  12. Secondary Organic Aerosol Production from Gasoline Vehicle Exhaust: Effects of Engine Technology, Cold Start, and Emission Certification Standard.

    Science.gov (United States)

    Zhao, Yunliang; Lambe, Andrew T; Saleh, Rawad; Saliba, Georges; Robinson, Allen L

    2018-02-06

    Secondary organic aerosol (SOA) formation from dilute exhaust from 16 gasoline vehicles was investigated using a potential aerosol mass (PAM) oxidation flow reactor during chassis dynamometer testing using the cold-start unified cycle (UC). Ten vehicles were equipped with gasoline direct injection engines (GDI vehicles) and six with port fuel injection engines (PFI vehicles) certified to a wide range of emissions standards. We measured similar SOA production from GDI and PFI vehicles certified to the same emissions standard; less SOA production from vehicles certified to stricter emissions standards; and, after accounting for differences in gas-particle partitioning, similar effective SOA yields across different engine technologies and certification standards. Therefore the ongoing, dramatic shift from PFI to GDI vehicles in the United States should not alter the contribution of gasoline vehicles to ambient SOA and the natural replacement of older vehicles with newer ones certified to stricter emissions standards should reduce atmospheric SOA levels. Compared to hot operations, cold-start exhaust had lower effective SOA yields, but still contributed more SOA overall because of substantially higher organic gas emissions. We demonstrate that the PAM reactor can be used as a screening tool for vehicle SOA production by carefully accounting for the effects of the large variations in emission rates.

  13. A study of diesel-hydrogen fuel exhaust emissions in a compression ignition engine/generator assembly

    International Nuclear Information System (INIS)

    Karri, V.; Hafez, H.A.; Kirkegaard, J.F.

    2006-01-01

    A compression engine and duel-fuel supply system was studied in order to determine the influence of hydrogen gas on a diesel engine's exhaust system. Commercially available solenoid valves and pulse actuators were used in a customized mechatronic control unit (MICU) to inject the hydrogen gas into the cylinders during the experiments. The MICU was designed as a generic external attachment. Diesel fuel was used to ignite the hydrogen gas-air mixture after compression. Various different electrical loads were then applied using an alternator in order to stimulate the engine governor and control diesel flow. Results of the study showed that measured carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NO x ) loads of exhaust emissions increased, while emissions of carbon dioxide (CO 2 ) decreased. Results also showed that higher temperatures and levels of NO x occurred when hydrogen was mixed with the induced air. It was concluded that higher levels of hydrogen may be needed to reduce emissions. 17 refs., 5 tabs., 2 figs

  14. 40 CFR 86.1310-90 - Exhaust gas sampling and analytical system; diesel engines.

    Science.gov (United States)

    2010-07-01

    ... avoid moisture condensation. A filter pair loading of 1 mg is typically proportional to a 0.1 g/bhp-hr..., the temperatures where condensation of water in the exhaust gases could occur. This may be achieved by... sampling zone in the primary dilution tunnel and as required to prevent condensation at any point in the...

  15. On-line Analysis of Diesel Engine Exhaust Gases by Selected Ion Flow Tube Mass Spectrometry

    Czech Academy of Sciences Publication Activity Database

    Smith, D.; Španěl, Patrik; Dabill, D.; Cocker, J.; Rajan, B.

    2004-01-01

    Roč. 18, - (2004), s. 2830-2838 ISSN 0951-4198 Institutional research plan: CEZ:AV0Z4040901 Keywords : diesel exhaust analysis * NOx compounds * SIFT-MS Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.750, year: 2004

  16. Research on shock wave characteristics in the isolator of central strut rocket-based combined cycle engine under Ma5.5

    Science.gov (United States)

    Wei, Xianggeng; Xue, Rui; Qin, Fei; Hu, Chunbo; He, Guoqiang

    2017-11-01

    A numerical calculation of shock wave characteristics in the isolator of central strut rocket-based combined cycle (RBCC) engine fueled by kerosene was carried out in this paper. A 3D numerical model was established by the DES method. The kerosene chemical kinetic model used the 9-component and 12-step simplified mechanism model. Effects of fuel equivalence ratio, inflow total temperature and central strut rocket on-off on shock wave characteristics were studied under Ma5.5. Results demonstrated that with the increase of equivalence ratio, the leading shock wave moves toward upstream, accompanied with higher possibility of the inlet unstart. However, the leading shock wave moves toward downstream as the inflow total temperature rises. After the central strut rocket is closed, the leading shock wave moves toward downstream, which can reduce risks of the inlet unstart. State of the shear layer formed by the strut rocket jet flow and inflow can influence the shock train structure significantly.

  17. Ablative Material Testing at Lewis Rocket Lab

    Science.gov (United States)

    1997-01-01

    The increasing demand for a low-cost, reliable way to launch commercial payloads to low- Earth orbit has led to the need for inexpensive, expendable propulsion systems for new launch vehicles. This, in turn, has renewed interest in less complex, uncooled rocket engines that have combustion chambers and exhaust nozzles fabricated from ablative materials. A number of aerospace propulsion system manufacturers have utilized NASA Lewis Research Center's test facilities with a high degree of success to evaluate candidate materials for application to new propulsion devices.

  18. Development of coaxial speaker-like non-contact electrostatic sensor for aviation engine exhaust electrostatic character research

    Directory of Open Access Journals (Sweden)

    Du Zhaoheng

    2015-01-01

    Full Text Available Electrostatic sensor is the most important equipment in aero-engine exhaust electrostatic character research. By comparing a variety of sensor test programs, the coaxial speaker-like noncontact electrostatic sensor program is proposed. Numerical simulation analysis indicates the electric field distribution of electrostatic sensor, the influence principle of gap width, outer diameter, center diameter, angle and other factors on the sensor capacitance values which identify the key indicators of electrostatic sensor. The experiment test shows that the simulation analysis is in good agreement with the experimental results.

  19. Numerical investigation of exhaust gas emissions for a dual fuel engine configuration using diesel and pongamia oil.

    Science.gov (United States)

    Mohamed Ibrahim, N H; Udayakumar, M

    2016-12-01

    The investigation presented in this paper focuses on determination of gaseous exhaust emissions by computational simulation during combustion in compression ignition engine with pongamia oil substitution. Combustion is modeled using Equilibrium Constants Method (ECM) with MATLAB program to calculate the mole fraction of 10 combustion products when pongamia oil is burnt along with diesel at variable equivalence ratio and blend ratio. It had been observed that pongamia oil substitution causes decrease in the CO emission and increase in the NO x emission as the blend ratio as well as equivalence ratio increases. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. 40 CFR 1048.101 - What exhaust emission standards must my engines meet?

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-IGNITION ENGINES... from your engines may not exceed the numerical emission standards in paragraph (a) of this section. See... specified in 40 CFR part 1065, subpart H, on which the engines in the engine family are designed to operate...

  1. Engine performance and exhaust emission analysis of a single cylinder diesel engine fuelled with water-diesel emulsion fuel blended with manganese metal additives

    Science.gov (United States)

    Muhsin Ithnin, Ahmad; Jazair Yahya, Wira; Baun Fletcher, Jasmine; Kadir, Hasannuddin Abd

    2017-10-01

    Water-in-diesel emulsion fuel (W/D) is one of the alternative fuels that capable to reduce the exhaust emission of diesel engine significantly especially the nitrogen oxides (NOx) and particulate matter (PM). However, the usage of W/D emulsion fuels contributed to higher CO emissions. Supplementing metal additive into the fuel is the alternate way to reduce the CO emissions and improve performance. The present paper investigates the effect of using W/D blended with organic based manganese metal additives on the diesel engine performance and exhaust emission. The test were carried out by preparing and analysing the results observed from five different tested fuel which were D2, emulsion fuel (E10: 89% D2, 10% - water, 1% - surfactant), E10Mn100, E10Mn150, E10Mn200. Organic based Manganese (100ppm, 150ppm, 200ppm) used as the additive in the three samples of the experiments. E10Mn200 achieved the maximum reduction of BSFC up to 13.66% and has the highest exhaust gas temperature. Whereas, E10Mn150 achieved the highest reduction of CO by 14.67%, and slightly increased of NOx emissions as compared to other emulsion fuels. Organic based manganese which act as catalyst promotes improvement of the emulsion fuel performance and reduced the harmful emissions discharged.

  2. Thermoeconomic multi-objective optimization of an organic Rankine cycle for exhaust waste heat recovery of a diesel engine

    International Nuclear Information System (INIS)

    Yang, Fubin; Zhang, Hongguang; Song, Songsong; Bei, Chen; Wang, Hongjin; Wang, Enhua

    2015-01-01

    In this paper, the ORC (Organic Rankine cycle) technology is adopted to recover the exhaust waste heat of diesel engine. The thermodynamic, economic and optimization models of the ORC system are established, respectively. Firstly, the effects of four key parameters, including evaporation pressure, superheat degree, condensation temperature and exhaust temperature at the outlet of the evaporator on the thermodynamic performances and economic indicators of the ORC system are investigated. Subsequently, based on the established optimization model, GA (genetic algorithm) is employed to solve the Pareto solution of the thermodynamic performances and economic indicators for maximizing net power output and minimizing total investment cost under diesel engine various operating conditions using R600, R600a, R601a, R245fa, R1234yf and R1234ze as working fluids. The most suitable working fluid used in the ORC system for diesel engine waste heat recovery is screened out, and then the corresponding optimal parameter regions are analyzed. The results show that thermodynamic performance of the ORC system is improved at the expense of economic performance. Among these working fluids, R245fa is considered as the most suitable working fluid for the ORC waste heat application of the diesel engine with comprehensive consideration of thermoeconomic performances, environmental impacts and safety levels. Under the various operating conditions of the diesel engine, the optimal evaporation pressure is in the range of 1.1 MPa–2.1 MPa. In addition, the optimal superheat degree and the exhaust temperature at the outlet of the evaporator are mainly influenced by the operating conditions of the diesel engine. The optimal condensation temperature keeps a nearly constant value of 298.15 K. - Highlights: • Thermoeconomic multi-objective optimization of an ORC (Organic Rankine cycle) system is conducted. • Sensitivity analysis of the decision variables is performed. • Genetic algorithm

  3. Performance and exhaust emissions of a gasoline engine with ethanol blended gasoline fuels using artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, G.; Ghobadian, B.; Tavakoli, T.; Faizollahnejad, M. [Tarbiat Modares University, Jalale-E-Aleahmad Highway, Tehran, P.O. Box: 14115-111 (Iran); Buttsworth, D.R.; Yusaf, T.F. [University of Southern Queensland, Toowoomba, 4350 QLD (Australia)

    2009-05-15

    The purpose of this study is to experimentally analyse the performance and the pollutant emissions of a four-stroke SI engine operating on ethanol-gasoline blends of 0%, 5%, 10%, 15% and 20% with the aid of artificial neural network (ANN). The properties of bioethanol were measured based on American Society for Testing and Materials (ASTM) standards. The experimental results revealed that using ethanol-gasoline blended fuels increased the power and torque output of the engine marginally. For ethanol blends it was found that the brake specific fuel consumption (bsfc) was decreased while the brake thermal efficiency ({eta}{sub b.th.}) and the volumetric efficiency ({eta}{sub v}) were increased. The concentration of CO and HC emissions in the exhaust pipe were measured and found to be decreased when ethanol blends were introduced. This was due to the high oxygen percentage in the ethanol. In contrast, the concentration of CO{sub 2} and NO{sub x} was found to be increased when ethanol is introduced. An ANN model was developed to predict a correlation between brake power, torque, brake specific fuel consumption, brake thermal efficiency, volumetric efficiency and emission components using different gasoline-ethanol blends and speeds as inputs data. About 70% of the total experimental data were used for training purposes, while the 30% were used for testing. A standard Back-Propagation algorithm for the engine was used in this model. A multi layer perception network (MLP) was used for nonlinear mapping between the input and the output parameters. It was observed that the ANN model can predict engine performance and exhaust emissions with correlation coefficient (R) in the range of 0.97-1. Mean relative errors (MRE) values were in the range of 0.46-5.57%, while root mean square errors (RMSE) were found to be very low. This study demonstrates that ANN approach can be used to accurately predict the SI engine performance and emissions. (author)

  4. Parametric Data from a Wind Tunnel Test on a Rocket-Based Combined-Cycle Engine Inlet

    Science.gov (United States)

    Fernandez, Rene; Trefny, Charles J.; Thomas, Scott R.; Bulman, Mel J.

    2001-01-01

    A 40-percent scale model of the inlet to a rocket-based combined-cycle (RBCC) engine was tested in the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT). The full-scale RBCC engine is scheduled for test in the Hypersonic Tunnel Facility (HTF) at NASA Glenn's Plum Brook Station at Mach 5 and 6. This engine will incorporate the configuration of this inlet model which achieved the best performance during the present experiment. The inlet test was conducted at Mach numbers of 4.0, 5.0, 5.5, and 6.0. The fixed-geometry inlet consists of an 8 deg.. forebody compression plate, boundary layer diverter, and two compressive struts located within 2 parallel sidewalls. These struts extend through the inlet, dividing the flowpath into three channels. Test parameters investigated included strut geometry, boundary layer ingestion, and Reynolds number (Re). Inlet axial pressure distributions and cross-sectional Pitot-pressure surveys at the base of the struts were measured at varying back-pressures. Inlet performance and starting data are presented. The inlet chosen for the RBCC engine self-started at all Mach numbers from 4 to 6. Pitot-pressure contours showed large flow nonuniformity on the body-side of the inlet. The inlet provided adequate pressure recovery and flow quality for the RBCC cycle even with the flow separation.

  5. Efficiency improvement of a spark-ignition engine at full load conditions using exhaust gas recirculation and variable geometry turbocharger – Numerical study

    International Nuclear Information System (INIS)

    Sjerić, Momir; Taritaš, Ivan; Tomić, Rudolf; Blažić, Mislav; Kozarac, Darko; Lulić, Zoran

    2016-01-01

    Highlights: • A cylinder model was calibrated according to experimental results. • A full cycle simulation model of turbocharged spark-ignition engine was made. • Engine performance with high pressure exhaust gas recirculation was studied. • Cooled exhaust gas recirculation lowers exhaust temperature and knock occurrence. • Leaner mixtures enable fuel consumption improvement of up to 11.2%. - Abstract: The numerical analysis of performance of a four cylinder highly boosted spark-ignition engine at full load is described in this paper, with the research focused on introducing high pressure exhaust gas recirculation for control of engine limiting factors such as knock, turbine inlet temperature and cyclic variability. For this analysis the cycle-simulation model which includes modeling of the entire engine flow path, early flame kernel growth, mixture stratification, turbulent combustion, in-cylinder turbulence, knock and cyclic variability was applied. The cylinder sub-models such as ignition, turbulence and combustion were validated by using the experimental results of a naturally aspirated multi cylinder spark-ignition engine. The high load operation, which served as a benchmark value, was obtained by a standard procedure used in calibration of engines, i.e. operation with fuel enrichment and without exhaust gas recirculation. By introducing exhaust gas recirculation and by optimizing other engine operating parameters, the influence of exhaust gas recirculation on engine performance is obtained. The optimum operating parameters, such as spark advance, intake pressure, air to fuel ratio, were found to meet the imposed requirements in terms of fuel consumption, knock occurrence, exhaust gas temperature and variation of indicated mean effective pressure. By comparing the results of the base point with the results that used exhaust gas recirculation the improvement in fuel consumption of 8.7%, 11.2% and 1.5% at engine speeds of 2000 rpm, 3500 rpm and 5000

  6. Combustion characteristics, performance and exhaust emissions of a diesel engine fueled with a waste cooking oil biodiesel mixture

    International Nuclear Information System (INIS)

    Can, Özer

    2014-01-01

    Highlights: • High quality biodiesel fuels can be produced by using different waste cooking oils. • Biodiesel fuel blends (in 5 and 10% vol) can be used without any negative effects. • Effects of biodiesel addition on the combustion and exhaust emissions were investigated. - Abstract: In this study, a mixture of biodiesel fuels produced from two different kinds of waste cooking oils was blended in 5% and 10% with No. 2 diesel fuel. The biodiesel/No. 2 diesel fuel blends were tested in a single-cylinder, direct injection, four-stroke, natural aspirated diesel engine under four different engine loads (BMEP 0.48–0.36–0.24–0.12 MPa) and 2200 rpm engine speed. Despite of the earlier start of injection, the detailed combustion and engine performance results showed that the ignition delay with the biodiesel addition was decreased for the all engine loads with the earlier combustion timings due to higher cetane number of biodiesel fuel. Meanwhile the maximum heat release rate and the in-cylinder pressure rise rate were slightly decreased and the combustion duration was generally increased with the biodiesel addition. However, significant changings were not observed on the maximum in-cylinder pressures. In addition, it was observed that the indicated mean effective pressure values were slightly varied depending on the start of combustion timing and the center of heat release location. It was found that 5% and 10% biodiesel fuel addition resulted in slightly increment on break specific fuel consumption (up to 4%) and reduction on break thermal efficiency (up to 2.8%). The biodiesel additions also increased NO x emissions up to 8.7% and decreased smoke and total hydrocarbon emissions for the all engine loads. Although there were no significant changes on CO emissions at the low and medium engine loads, some reductions were observed at the full engine load. Also, CO 2 emissions were slightly increased for the all engine loads

  7. Influence of biofuels on exhaust gas and noise emissions of small industrial diesel engines; Einfluss von Biokraftstoffen auf die Abgas- und Geraeuschemission kleiner Industriedieselmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Spessert, B.M. [Fachhochschule Jena (Germany). Fachgebiet Kraft- und Arbeitsmaschinen; Schleicher, A. [Fachhochschule Jena (Germany). Fachgebiet Umweltmesstechnik

    2007-03-15

    At small industrial diesel engines, as they were brought in oftentimes on building sites, in the farming and forest industry and on boats, biofuels are increasingly used. In a research project of the University of Applied Sciences Jena, Germany, thus the changes of the exhaust gas pollutant and noise emissions of these diesel engines were investigated. Test fuels were diesel fuel, and also biofuels as biodiesel (RME), rape seed oil and sun flower oil. Depending on the operating point these biofuels increased or reduced the emissions of exhaust gas and noise of the investigated engines clearly. (orig.)

  8. Effects of fuels, engine load and exhaust after-treatment on diesel engine SVOC emissions and development of SVOC profiles for receptor modeling

    Science.gov (United States)

    Huang, Lei; Bohac, Stanislav V.; Chernyak, Sergei M.; Batterman, Stuart A.

    2015-01-01

    Diesel exhaust emissions contain numerous semivolatile organic compounds (SVOCs) for which emission information is limited, especially for idling conditions, new fuels and the new after-treatment systems. This study investigates exhaust emissions of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and sterane and hopane petroleum biomarkers from a heavy-duty (6.4 L) diesel engine at various loads (idle, 600 and 900 kPa BMEP), with three types of fuel (ultra-low sulfur diesel or ULSD, Swedish low aromatic diesel, and neat soybean biodiesel), and with and without a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). Swedish diesel and biodiesel reduced emissions of PM2.5, Σ15PAHs, Σ11NPAHs, Σ5Hopanes and Σ6Steranes, and biodiesel resulted in the larger reductions. However, idling emissions increased for benzo[k]fluoranthene (Swedish diesel), 5-nitroacenaphthene (biodiesel) and PM2.5 (biodiesel), a significant result given the attention to exposures from idling vehicles and the toxicity of high-molecular-weight PAHs and NPAHs. The DOC + DPF combination reduced PM2.5 and SVOC emissions during DPF loading (>99% reduction) and DPF regeneration (83–99%). The toxicity of diesel exhaust, in terms of the estimated carcinogenic risk, was greatly reduced using Swedish diesel, biodiesel fuels and the DOC + DPF. PAH profiles showed high abundances of three and four ring compounds as well as naphthalene; NPAH profiles were dominated by nitro-naphthalenes, 1-nitropyrene and 9-nitroanthracene. Both the emission rate and the composition of diesel exhaust depended strongly on fuel type, engine load and after-treatment system. The emissions data and chemical profiles presented are relevant to the development of emission inventories and exposure and risk assessments. PMID:25709535

  9. Effects of fuels, engine load and exhaust after-treatment on diesel engine SVOC emissions and development of SVOC profiles for receptor modeling.

    Science.gov (United States)

    Huang, Lei; Bohac, Stanislav V; Chernyak, Sergei M; Batterman, Stuart A

    2015-02-01

    Diesel exhaust emissions contain numerous semivolatile organic compounds (SVOCs) for which emission information is limited, especially for idling conditions, new fuels and the new after-treatment systems. This study investigates exhaust emissions of particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and sterane and hopane petroleum biomarkers from a heavy-duty (6.4 L) diesel engine at various loads (idle, 600 and 900 kPa BMEP), with three types of fuel (ultra-low sulfur diesel or ULSD, Swedish low aromatic diesel, and neat soybean biodiesel), and with and without a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF). Swedish diesel and biodiesel reduced emissions of PM 2.5 , Σ 15 PAHs, Σ 11 NPAHs, Σ 5 Hopanes and Σ 6 Steranes, and biodiesel resulted in the larger reductions. However, idling emissions increased for benzo[k]fluoranthene (Swedish diesel), 5-nitroacenaphthene (biodiesel) and PM 2.5 (biodiesel), a significant result given the attention to exposures from idling vehicles and the toxicity of high-molecular-weight PAHs and NPAHs. The DOC + DPF combination reduced PM 2.5 and SVOC emissions during DPF loading (>99% reduction) and DPF regeneration (83-99%). The toxicity of diesel exhaust, in terms of the estimated carcinogenic risk, was greatly reduced using Swedish diesel, biodiesel fuels and the DOC + DPF. PAH profiles showed high abundances of three and four ring compounds as well as naphthalene; NPAH profiles were dominated by nitro-naphthalenes, 1-nitropyrene and 9-nitroanthracene. Both the emission rate and the composition of diesel exhaust depended strongly on fuel type, engine load and after-treatment system. The emissions data and chemical profiles presented are relevant to the development of emission inventories and exposure and risk assessments.

  10. Nuclear thermal rockets using indigenous Martian propellants

    International Nuclear Information System (INIS)

    Zubrin, R.M.

    1989-01-01

    This paper considers a novel concept for a Martian descent and ascent vehicle, called NIMF (for nuclear rocket using indigenous Martian fuel), the propulsion for which will be provided by a nuclear thermal reactor which will heat an indigenous Martian propellant gas to form a high-thrust rocket exhaust. The performance of each of the candidate Martian propellants, which include CO2, H2O, CH4, N2, CO, and Ar, is assessed, and the methods of propellant acquisition are examined. Attention is also given to the issues of chemical compatibility between candidate propellants and reactor fuel and cladding materials, and the potential of winged Mars supersonic aircraft driven by this type of engine. It is shown that, by utilizing the nuclear landing craft in combination with a hydrogen-fueled nuclear thermal interplanetary vehicle and a heavy lift booster, it is possible to achieve a manned Mars mission in one launch. 6 refs

  11. Experimental study on Rankine cycle evaporator efficiency intended for exhaust waste heat recovery of a diesel engine

    Directory of Open Access Journals (Sweden)

    Milkov Nikolay

    2017-01-01

    Full Text Available The paper pressents an experimental study of Rankine cycle evaporator efficiency. Water was chosen as the working fluid in the system. The experimental test was conducted on a test bench equipped with a burner charged by compressed fresh air. Generated exhaust gases parameters were previously determined over the diesel engine operating range (28 engine operating points were studied. For each test point the working fluid parameters (flow rate and evaporating pressure were varied. Thus, the enthalpy flow through the heat exchanger was determined. Heat exchanger was designed as 23 helical tubes are inserted. On the basis of the results, it was found out that efficiency varies from 25 % to 51,9 %. The optimal working fluid pressure is 20 bar at most of the operating points while the optimum fluid mass flow rate varies from 2 g/s to 10 g/s.

  12. Review of homogeneous charge compression ignition (HCCI) combustion engines and exhaust gas recirculation (EGR) effects on HCCI

    Science.gov (United States)

    Akma Tuan Kamaruddin, Tengku Nordayana; Wahid, Mazlan Abdul; Sies, Mohsin Mohd

    2012-06-01

    This paper describes the development in ICE which leads to the new advanced combustion mode named Homogeneous Charge Compression Ignition (HCCI). It explains regarding the theory and working principle of HCCI plus the difference of the process in gasoline and diesel fuelled engines. Many of pioneer and recent research works are discussed to get the current state of art about HCCI. It gives a better indication on the potential of this method in improving the fuel efficiency and emission produced by the vehicles' engine. Apart from the advantages, the challenges and future trend of this technology are also included. HCCI is applying few types of control strategy in producing the optimum performance. This paper looks into Exhaust Gas Recirculation (EGR) as one of the control strategies.

  13. An experimental study on performance and exhaust emissions of a diesel engine fuelled with tobacco seed oil methyl ester

    International Nuclear Information System (INIS)

    Usta, N.

    2005-01-01

    Tobacco seeds are a by product of tobacco leaves production. To the author's best knowledge, unlike tobacco leaves, tobacco seeds are not collected from fields and are not commercial products. However, tobacco seeds contain significant amounts of oil. Although tobacco seed oil is a non-edible vegetable oil, it can be utilized for biodiesel production as a new renewable alternative diesel engine fuel. In this study, an experimental study on the performance and exhaust emissions of a turbocharged indirect injection diesel engine fuelled with tobacco seed oil methyl ester was performed at full and partial loads. The results showed that the addition of tobacco seed oil methyl ester to the diesel fuel reduced CO and SO 2 emissions while causing slightly higher NO x emissions. Meanwhile, it was found that the power and the efficiency increased slightly with the addition of tobacco seed oil methyl ester. (Author)

  14. Experimental aerodynamic and acoustic model testing of the Variable Cycle Engine (VCE) testbed coannular exhaust nozzle system

    Science.gov (United States)

    Nelson, D. P.; Morris, P. M.

    1980-01-01

    Aerodynamic performance and jet noise characteristics of a one sixth scale model of the variable cycle engine testbed exhaust system were obtained in a series of static tests over a range of simulated engine operating conditions. Model acoustic data were acquired. Data were compared to predictions of coannular model nozzle performance. The model, tested with an without a hardwall ejector, had a total flow area equivalent to a 0.127 meter (5 inch) diameter conical nozzle with a 0.65 fan to primary nozzle area ratio and a 0.82 fan nozzle radius ratio. Fan stream temperatures and velocities were varied from 422 K to 1089 K (760 R to 1960 R) and 434 to 755 meters per second (1423 to 2477 feet per second). Primary stream properties were varied from 589 to 1089 K (1060 R to 1960 R) and 353 to 600 meters per second (1158 to 1968 feet per second). Exhaust plume velocity surveys were conducted at one operating condition with and without the ejector installed. Thirty aerodynamic performance data points were obtained with an unheated air supply. Fan nozzle pressure ratio was varied from 1.8 to 3.2 at a constant primary pressure ratio of 1.6; primary pressure ratio was varied from 1.4 to 2.4 while holding fan pressure ratio constant at 2.4. Operation with the ejector increased nozzle thrust coefficient 0.2 to 0.4 percent.

  15. Effect of fin attachment on thermal stress reduction of exhaust manifold of an off road diesel engine

    Institute of Scientific and Technical Information of China (English)

    Ali; Akbar; Partoaa; Morteza; Abdolzadeh; Masoud; Rezaeizadeh

    2017-01-01

    The effect of fin attachment on the thermal stress reduction of exhaust manifold of an off road diesel engine(Komatsu HD325-6) was investigated.For doing this,coupled thermo-fluid-solid analysis of exhaust manifold of the off road diesel engine was carried out.The thermal analysis,including thermal flow,thermal stress,and the thermal deformation of the manifold was investigated.The flow inside the manifold was simulated and then its properties including velocity,pressure,and temperature were obtained.The flow properties were transferred to the solid model and then the thermal stresses and the thermal deformations of the manifold under different operating conditions were calculated.Finally,based on the predicted thermal stresses and thermal deformations of the manifold body shell,two fin types as well as body shell thickness increase were applied in the critical induced thermal stress area of the manifold to reduce the thermal stress and thermal deformation.The results of the above modifications show that the combined modifications,i.e.the thickness increase and the fin attachment,decrease the thermal stresses by up to 28% and the contribution of the fin attachment in this reduction is much higher compared to the shell thickness increase.

  16. Effects of premixed diethyl ether (DEE) on combustion and exhaust emissions in a HCCI-DI diesel engine

    International Nuclear Information System (INIS)

    Cinar, Can; Can, Ozer; Sahin, Fatih; Yucesu, H. Serdar

    2010-01-01

    In this study, the effects of premixed ratio of diethyl ether (DEE) on the combustion and exhaust emissions of a single-cylinder, HCCI-DI engine were investigated. The experiments were performed at the engine speed of 2200 rpm and 19 N m operating conditions. The amount of the premixed DEE was controlled by a programmable electronic control unit (ECU) and the DEE injection was conducted into the intake air charge using low pressure injector. The premixed fuel ratio (PFR) of DEE was changed from 0% to 40% and results were compared to neat diesel operation. The percentages of premixed fuel were calculated from the energy ratio of premixed DEE fuel to total energy rate of the fuels. The experimental results show that single stage ignition was found with the addition of premixed DEE fuel. Increasing and phasing in-cylinder pressure and heat release were observed in the premixed stage of the combustion. Lower diffusion combustion was also occurred. Cycle-to cycle variations were very small with diesel fuel and 10% DEE premixed fuel ratio. Audible knocking occurred with 40% DEE premixed fuel ratio. NO x -soot trade-off characteristics were changed and improvements were found simultaneously. NO x and soot emissions decreased up to 19.4% and 76.1%, respectively, while exhaust gas temperature decreased by 23.8%. On the other hand, CO and HC emissions increased.

  17. Nuclear-powered rocket of the future

    Energy Technology Data Exchange (ETDEWEB)

    Yunqiao, B

    1979-06-01

    A possible manned mission to Mars with a crew of 7 in an 80-meter-long nuclear-powered rocket will take 180 days to reach its destination, will spend 10 to 14 days on the surface, and will take 200 days to return. A nuclear-powered engine (using U-235 or U-239) is the most likely means of propulsion. Four designs are described. The superheated exhaust engine will use a reactor to heat liquid hydrogen to over 4000/sup 0/C, after which it will be ejected from the exhaust. A plasma compression engine will use electric current produced by a reactor to heat hydrogen to plasma temperature (70,000/sup 0/C), after which it will be ejected through the exhaust by a magnetic field. In a gaseous-core reactor engine, gaseous fuel will heat liquid hydrogen to over 9,000/sup 0/C and use it as the propellant. The boldest solution is a proposal to use small nuclear explosions as the propulsive force. The first alternative will probably not produce enough thrust, while there will be a difficulty producing sufficient electricity in the second alternative. The other two alternatives seem promising.

  18. The issue of ensuring the safe explosion of the spent orbital stages of a launch vehicle with propulsion rocket engine

    Directory of Open Access Journals (Sweden)

    Trushlyakov Valeriy I.

    2017-01-01

    Full Text Available A method for increasing the safe explosion of the spent orbital stages of a space launch vehicle (SLV with a propulsion rocket engine (PRE based on the gasification of unusable residues propellant and venting fuel tanks. For gasification and ventilation the hot gases used produced by combustion of the specially selected gas generating composition (GGC with a set of physical and chemical properties. Excluding the freezing of the drainage system on reset gasified products (residues propellant+pressurization gas+hot gases in the near-Earth space is achieved by selecting the physical-chemical characteristics of the GGC. Proposed steps to ensure rotation of gasified products due to dumping through the drainage system to ensure the most favorable conditions for propellant gasification residues. For example, a tank with liquid oxygen stays with the orbital spent second stage of the SLV “Zenit”, which shows the effectiveness of the proposed method.

  19. Effect of injection timing on the exhaust emissions of a diesel engine using diesel-methanol blends

    Energy Technology Data Exchange (ETDEWEB)

    Sayin, Cenk; Gumus, Metin [Department of Mechanical Education, Marmara University, 34722 Istanbul (Turkey); Ilhan, Murat [Raytheon Training International GmbH, GM Academy, 34843 Istanbul (Turkey); Canakci, Mustafa [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey)]|[Alternative Fuels R and D Center, Kocaeli University, 41040 Kocaeli (Turkey)

    2009-05-15

    Environmental concerns and limited resource of petroleum fuels have caused interests in the development of alternative fuels for internal combustion (IC) engines. For diesel engines, alcohols are receiving increasing attention because they are oxygenated and renewable fuels. Therefore, in this study, the effect of injection timing on the exhaust emissions of a single cylinder, naturally aspirated, four-stroke, direct injection diesel engine has been experimentally investigated by using methanol-blended diesel fuel from 0% to 15% with an increment of 5%. The tests were conducted for three different injection timings (15 , 20 and 25 CA BTDC) at four different engine loads (5 Nm, 10 Nm, 15 Nm, 20 Nm) at 2200 rpm. The experimental test results showed that Bsfc, NO{sub x} and CO{sub 2} emissions increased as BTE, smoke opacity, CO and UHC emissions decreased with increasing amount of methanol in the fuel mixture. When compared the results to those of original injection timing, NO{sub x} and CO{sub 2} emissions decreased, smoke opacity, UHC and CO emissions increased for the retarded injection timing (15 CA BTDC). On the other hand, with the advanced injection timing (25 CA BTDC), decreasing smoke opacity, UHC and CO emissions diminished, and NO{sub x} and CO{sub 2} emissions boosted at all test conditions. In terms of Bsfc and BTE, retarded and advanced injection timings gave negative results for all fuel blends in all engine loads. (author)

  20. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.