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Sample records for ratio engine speed

  1. A Study on the Effects of Compression Ratio, Engine Speed and Equivalence Ratio on HCCI Combustion of DME

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper

    2007-01-01

    An experimental study has been carried out on the homogeneous charge compression ignition (HCCI) combustion of Dimethyl Ether (DME). The study was performed as a parameter variation of engine speed and compression ratio on excess air ratios of approximately 2.5, 3 and 4. The compression ratio...... was adjusted in steps to find suitable regions of operation, and the effect of engine speed was studied at 1000, 2000 and 3000 RPM. It was found that leaner excess air ratios require higher compression ratios to achieve satisfactory combustion. Engine speed also affects operation significantly....

  2. A Study on the Effects of Compression Ratio, Engine Speed and Equivalence Ratio on HCCI Combustion of DME

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr; Schramm, Jesper

    2007-01-01

    An experimental study has been carried out on the homogeneous charge compression ignition (HCCI) combustion of Dimethyl Ether (DME). The study was performed as a parameter variation of engine speed and compression ratio on excess air ratios of approximately 2.5, 3 and 4. The compression ratio was...

  3. Effect of compression ratio, equivalence ratio and engine speed on the performance and emission characteristics of a spark ignition engine using hydrogen as a fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sadiq Al-Baghdadi, M.A.R. [University of Babylon (Iraq). Dept. of Mechanical Engineering

    2004-12-01

    The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. Researchers have found that hydrogen presents the best and an unprecedented solution to the energy crises and pollution problems, due to its superior combustion qualities and availability. This paper discusses analytically and provides data on the effect of compression ratio, equivalence ratio and engine speed on the engine performance, emissions and pre-ignition limits of a spark ignition engine operating on hydrogen fuel. These data are important in order to understand the interaction between engine performance and emission parameters, which will help engine designers when designing for hydrogen. (author)

  4. Envera Variable Compression Ratio Engine

    Energy Technology Data Exchange (ETDEWEB)

    Charles Mendler

    2011-03-15

    technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsizing with variable compression ratio and use of the extended Atkinson cycle can provide large fuel economy gains that are exceptionally cost effective. Analysis indicates that a 2.2L supercharged Envera VCR engine can match the torque of a larger V8 engine at 2000 rpm. The VCR engine's high torque value at low engine speed is beneficial for maintaining the driving feel and responsiveness of the larger V8 engine. The Envera VCR engine will attain high efficiency at {approx}100 Nm primarily due to the combination of engine down-sizing and use of the Atkinson cycle. Qualitatively the fuel economy gain realized from down-sizing from a V8 to an Atkinson-cycle I-4 is about twice as large as the benefits from down-sizing from a V8 to a Turbo V6 when evaluated at 100 Nm 2000 rpm.

  5. BENEFITS AND CHALLENGES OF VARIABLE COMPRESSION RATIO AT DIESEL ENGINES

    OpenAIRE

    Radivoje B Pešić; Saša T Milojević; Stevan P Veinović

    2010-01-01

    The compression ratio strongly affects the working process and provides an exceptional degree of control over engine performance. In conventional internal combustion engines, the compression ratio is fixed and their performance is therefore a compromise between conflicting requirements. One fundamental problem is that drive units in the vehicles must successfully operate at variable speeds and loads and in different ambient conditions. If a diesel engine has a fixed compression ratio, a minim...

  6. Advanced nonlinear engine speed control systems

    DEFF Research Database (Denmark)

    Vesterholm, Thomas; Hendricks, Elbert

    1994-01-01

    Several subsidiary control problems have turned out to be important for improving driveability and fuel consumption in modern spark ignition (SI) engine cars. Among these are idle speed control and cruise control. In this paper the idle speed and cruise control problems will be treated as one......: accurately tracking of a desired engine speed in the presence of model uncertainties and severe load disturbances. This is accomplished by using advanced nonlinear control techniques such as input/output-linearization and sliding mode control. These techniques take advantage of a nonlinear model...... of the engine dynamics, a mean value engine model....

  7. Optimization of powered Stirling heat engine with finite speed thermodynamics

    International Nuclear Information System (INIS)

    Ahmadi, Mohammad H.; Ahmadi, Mohammad Ali; Pourfayaz, Fathollah; Bidi, Mokhtar; Hosseinzade, Hadi; Feidt, Michel

    2016-01-01

    Highlights: • Based on finite speed method and direct method, the optimal performance is investigated. • The effects of major parameters on the optimal performance are investigated. • The accuracy of the results was compared with previous works. - Abstract: Popular thermodynamic analyses including finite time thermodynamic analysis was lately developed based upon external irreversibilities while internal irreversibilities such as friction, pressure drop and entropy generation were not considered. The aforementioned disadvantage reduces the reliability of the finite time thermodynamic analysis in the design of an accurate Stirling engine model. Consequently, the finite time thermodynamic analysis could not sufficiently satisfy researchers for implementing in design and optimization issues. In this study, finite speed thermodynamic analysis was employed instead of finite time thermodynamic analysis for studying Stirling heat engine. The finite speed thermodynamic analysis approach is based on the first law of thermodynamics for a closed system with finite speed and the direct method. The effects of heat source temperature, regenerating effectiveness, volumetric ratio, piston stroke as well as rotational speed are included in the analysis. Moreover, maximum output power in optimal rotational speed was calculated while pressure losses in the Stirling engine were systematically considered. The result reveals the accuracy and the reliability of the finite speed thermodynamic method in thermodynamic analysis of Stirling heat engine. The outcomes can help researchers in the design of an appropriate and efficient Stirling engine.

  8. Tickover speed controller for car engines

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, R L

    1980-05-22

    In general, the tickover speed of a car engine is made sufficiently high, in order to permit an assumed maximum load to be taken from the engine at tickover. This setting of the tickover speed is usually done by stops in the fuel supply. Matching the actual load would lead to lower fuel consumption, without any danger of the engine stalling. The purpose of the invention is to provide a tickover speed controller, so that the tickover speed is adjusted by electronic control equipment, independently of the machine load. The fuel consumption on tickover is reduced and the emission of noxious substances is decreased. The electro-magnetic control of the throttle valve tickover setting is explained by extensive section drawings of the system. This process dispenses with the special tickover cams for a cold start.

  9. BENEFITS AND CHALLENGES OF VARIABLE COMPRESSION RATIO AT DIESEL ENGINES

    Directory of Open Access Journals (Sweden)

    Radivoje B Pešić

    2010-01-01

    Full Text Available The compression ratio strongly affects the working process and provides an exceptional degree of control over engine performance. In conventional internal combustion engines, the compression ratio is fixed and their performance is therefore a compromise between conflicting requirements. One fundamental problem is that drive units in the vehicles must successfully operate at variable speeds and loads and in different ambient conditions. If a diesel engine has a fixed compression ratio, a minimal value must be chosen that can achieve a reliable self-ignition when starting the engine in cold start conditions. In diesel engines, variable compression ratio provides control of peak cylinder pressure, improves cold start ability and low load operation, enabling the multi-fuel capability, increase of fuel economy and reduction of emissions. This paper contains both theoretical and experimental investigation of the impact that automatic variable compression ratios has on working process parameters in experimental diesel engine. Alternative methods of implementing variable compression ratio are illustrated and critically examined.

  10. Hige Compression Ratio Turbo Gasoline Engine Operation Using Alcohol Enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Heywood, John [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Jo, Young Suk [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lewis, Raymond [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Bromberg, Leslie [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Heywood, John [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-01-29

    The overall objective of this project was to quantify the potential for improving the performance and efficiency of gasoline engine technology by use of alcohols to suppress knock. Knock-free operation is obtained by direct injection of a second “anti-knock” fuel such as ethanol, which suppresses knock when, with gasoline fuel, knock would occur. Suppressing knock enables increased turbocharging, engine downsizing, and use of higher compression ratios throughout the engine’s operating map. This project combined engine testing and simulation to define knock onset conditions, with different mixtures of gasoline and alcohol, and with this information quantify the potential for improving the efficiency of turbocharged gasoline spark-ignition engines, and the on-vehicle fuel consumption reductions that could then be realized. The more focused objectives of this project were therefore to: Determine engine efficiency with aggressive turbocharging and downsizing and high compression ratio (up to a compression ratio of 13.5:1) over the engine’s operating range; Determine the knock limits of a turbocharged and downsized engine as a function of engine speed and load; Determine the amount of the knock-suppressing alcohol fuel consumed, through the use of various alcohol-gasoline and alcohol-water gasoline blends, for different driving cycles, relative to the gasoline consumed; Determine implications of using alcohol-boosted engines, with their higher efficiency operation, in both light-duty and medium-duty vehicle sectors.

  11. THE EFFECT OF COMPRESSION RATIO VARIATIONS ON THE ENGINE PERFORMANCE PARAMETRES IN SPARK IGNITION ENGINES

    Directory of Open Access Journals (Sweden)

    Yakup SEKMEN

    2005-01-01

    Full Text Available Performance of the spark ignition engines may be increased by changing the geometrical compression ratio according to the amount of charging in cylinders. The designed geometrical compression ratio can be realized as an effective compression ratio under the full load and full open throttle conditions since the effective compression ratio changes with the amount of charging into the cylinder in spark ignition engines. So, this condition of the spark ignition engines forces designers to change their geometrical compression ratio according to the amount of charging into the cylinder for improvement of performance and fuel economy. In order to improve the combustion efficiency, fuel economy, power output, exhaust emissions at partial loads, compression ratio must be increased; but, under high load and low speed conditions to prevent probable knock and hard running the compression ratio must be decreased gradually. In this paper, relation of the performance parameters to compression ratio such as power, torque, specific fuel consumption, cylindir pressure, exhaust gas temperature, combustion chamber surface area/volume ratio, thermal efficiency, spark timing etc. in spark ignition engines have been investigated and using of engines with variable compression ratio is suggested to fuel economy and more clear environment.

  12. Engine control system having speed-based timing

    Science.gov (United States)

    Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

    2012-02-14

    A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

  13. Speed Control of General Purpose Engine with Electronic Governor

    Science.gov (United States)

    Sawut, Umerujan; Tohti, Gheyret; Takigawa, Buso; Tsuji, Teruo

    This paper presents a general purpose engine speed control system with an electronic governor in order to improve the current system with a mechanical governor which shows unstable characteristics by change of mecanical friction or A/F ratio (Air/Fuel ratio). For the control system above, there are problems that the feedback signal is only a crank angle because of cost and the controlled object is a general purpose engine which is strongly nonlinear. In order to overcome these problems, the system model is shown for the dynamic estimation of the amount of air flow and the robust controller is designed. That is, the proposed system includes the robust sliding-mode controller by the feedback signal of only a crank angle where Genetic Algorithm is applied for the controller design. The simulation and the experiments by MATLAB/Simulink are performed to show the effectiveness of our proposal.

  14. Multiroller traction drive speed reducer: Evaluation for automotive gas turbine engine

    Science.gov (United States)

    Rohn, D. A.; Anderson, N. E.; Loewenthal, S. H.

    1982-01-01

    Tests were conducted on a nominal 14:1 fixed-ratio Nasvytis multiroller traction drive retrofitted as the speed reducer in an automotive gas turbine engine. Power turbine speeds of 45,000 rpm and a drive output power of 102 kW (137 hp) were reached. The drive operated under both variable roller loading (proportional to torque) and fixed roller loading (automatic loading mechanism locked). The drive operated smoothly and efficiently as the engine speed reducer. Engine specific fuel consumption with the traction speed reducer was comparable to that with the original helical gearset.

  15. Automatic Tuning of Control Parameters for Single Speed Engines

    OpenAIRE

    Olsson, Johan

    2004-01-01

    In Scania’s single speed engines for industrial and marine use, the engine speed is controlled by a PI-controller. This controller is tuned independent of engine type and application. This brings certain disadvantages since the engines are used in a wide range of applications where the dynamics may differ. In this thesis, the possibility to tune the controller automatically for a specific engine installation has been investigated. The work shows that automatic tuning is possible. By performin...

  16. Tip Speed Ratio Based Maximum Power Tracking Control of Variable Speed Wind Turbines; A Comprehensive Design

    Directory of Open Access Journals (Sweden)

    Murat Karabacak

    2017-08-01

    Full Text Available The most primitive control method of wind turbines used to generate electric energy from wind is the fixed speed control method. With this method, it is not possible that turbine input power is transferred to grid at maximum rate. For this reason, Maximum Power Tracking (MPT schemes are proposed. In order to implement MPT, the propeller has to rotate at a different speed for every different wind speed. This situation has led MPT based systems to be called Variable Speed Wind Turbine (VSWT systems. In VSWT systems, turbine input power can be transferred to grid at rates close to maximum power. When MPT based control of VSWT systems is the case, two important processes come into prominence. These are instantaneously determination and tracking of MPT point. In this study, using a Maximum Power Point Tracking (MPPT method based on tip speed ratio, power available in wind is transferred into grid over a back to back converter at maximum rate via a VSWT system with permanent magnet synchronous generator (PMSG. Besides a physical wind turbine simulator is modelled and simulated. Results show that a time varying MPPT point is tracked with a high performance.

  17. Assessment of n-pentanol/Calophyllum inophyllum/diesel blends on the performance, emission, and combustion characteristics of a constant-speed variable compression ratio direct injection diesel engine.

    Science.gov (United States)

    Ramakrishnan, Purnachandran; Kasimani, Ramesh; Peer, Mohamed Shameer; Rajamohan, Sakthivel

    2018-05-01

    Alcohol is used as an additive for a long time with the petroleum-based fuels. In this study, the higher alcohol, n-pentanol, was used as an additive to Calophyllum inophyllum (CI) biodiesel/diesel blends at 10, 15, and 20% by volume. In all blends, the ratio of CI was maintained at 20% by volume. The engine characteristics of the pentanol fuel blends were compared with the diesel and CI20 (Calophyllum inophyllum 20% and diesel 80%) biodiesel blend. The nitrogen oxide (NO) emission of the pentanol fuel blends showed an increased value than CI20 and neat diesel fuel. The carbon dioxide (CO 2 ) also increased with increase in pentanol addition with the fuel blends than CI20 fuel blend and diesel. The carbon monoxide (CO) and hydrocarbon (HC) emissions were decreased with increase in pentanol proportion in the blend than the CI20 fuel and diesel. The smoke emission was reduced and the combustion characteristics of the engine were also improved by using pentanol blended fuels. From this investigation, it is suggested that 20% pentanol addition with the biodiesel/diesel fuel is suitable for improved performance and combustion characteristics of a diesel engine without any engine modifications, whereas CO 2 and NO emissions increased with addition of pentanol due to effective combustion.

  18. High-speed and high-ratio referential genome compression.

    Science.gov (United States)

    Liu, Yuansheng; Peng, Hui; Wong, Limsoon; Li, Jinyan

    2017-11-01

    The rapidly increasing number of genomes generated by high-throughput sequencing platforms and assembly algorithms is accompanied by problems in data storage, compression and communication. Traditional compression algorithms are unable to meet the demand of high compression ratio due to the intrinsic challenging features of DNA sequences such as small alphabet size, frequent repeats and palindromes. Reference-based lossless compression, by which only the differences between two similar genomes are stored, is a promising approach with high compression ratio. We present a high-performance referential genome compression algorithm named HiRGC. It is based on a 2-bit encoding scheme and an advanced greedy-matching search on a hash table. We compare the performance of HiRGC with four state-of-the-art compression methods on a benchmark dataset of eight human genomes. HiRGC takes compress about 21 gigabytes of each set of the seven target genomes into 96-260 megabytes, achieving compression ratios of 217 to 82 times. This performance is at least 1.9 times better than the best competing algorithm on its best case. Our compression speed is also at least 2.9 times faster. HiRGC is stable and robust to deal with different reference genomes. In contrast, the competing methods' performance varies widely on different reference genomes. More experiments on 100 human genomes from the 1000 Genome Project and on genomes of several other species again demonstrate that HiRGC's performance is consistently excellent. The C ++ and Java source codes of our algorithm are freely available for academic and non-commercial use. They can be downloaded from https://github.com/yuansliu/HiRGC. jinyan.li@uts.edu.au. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  19. Development trend of low bypass ratio turbofan engines. Tei baipasu hi tabo fan engine no kaihatsu doko

    Energy Technology Data Exchange (ETDEWEB)

    Yashima, S [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1994-03-10

    As a turbojet engine gets a thrust by blowing out the exhaust of a gas generator, for decreasing the fuel consumption ratio is more advantageous when a bypass air quantity is made as much as possible. Therefore in the subsonic speed passenger aircrafts putting an economy in the first place, the high bypass ratio turbofan engines are used. Even in case of the subsonic speed aircrafts, in addition, for the trainer airplanes and fighters, a type to be built in the engines in the fuselages, the low bypass ratio engines with small front areas are used. When a turbofan engine with a low bypass ratio is picked up, therefore recently, it is general that a military engine with a bypass ratio under 1 (about 0.5 is frequent) is pointed, as for a development trend also from a viewpoint of the performance improvement as a military engine, an improvement of the thrust-weight ratio and specific thrust are attached importance to. In this paper, these performance parameters, a trend to make them lighter weight, and the elementary technologies peculiar to a low bypass ratio engine are described, and moreover the study and development state in Europe, America and Japan are put in order. 8 refs., 14 figs., 2 tabs.

  20. A Mathematical Model of Marine Diesel Engine Speed Control System

    Science.gov (United States)

    Sinha, Rajendra Prasad; Balaji, Rajoo

    2018-02-01

    Diesel engine is inherently an unstable machine and requires a reliable control system to regulate its speed for safe and efficient operation. Also, the diesel engine may operate at fixed or variable speeds depending upon user's needs and accordingly the speed control system should have essential features to fulfil these requirements. This paper proposes a mathematical model of a marine diesel engine speed control system with droop governing function. The mathematical model includes static and dynamic characteristics of the control loop components. Model of static characteristic of the rotating fly weights speed sensing element provides an insight into the speed droop features of the speed controller. Because of big size and large time delay, the turbo charged diesel engine is represented as a first order system or sometimes even simplified to a pure integrator with constant gain which is considered acceptable in control literature. The proposed model is mathematically less complex and quick to use for preliminary analysis of the diesel engine speed controller performance.

  1. Determination of combustion parameters using engine crankshaft speed

    Science.gov (United States)

    Taglialatela, F.; Lavorgna, M.; Mancaruso, E.; Vaglieco, B. M.

    2013-07-01

    Electronic engine controls based on real time diagnosis of combustion process can significantly help in complying with the stricter and stricter regulations on pollutants emissions and fuel consumption. The most important parameter for the evaluation of combustion quality in internal combustion engines is the in-cylinder pressure, but its direct measurement is very expensive and involves an intrusive approach to the cylinder. Previous researches demonstrated the direct relationship existing between in-cylinder pressure and engine crankshaft speed and several authors tried to reconstruct the pressure cycle on the basis of the engine speed signal. In this paper we propose the use of a Multi-Layer Perceptron neural network to model the relationship between the engine crankshaft speed and some parameters derived from the in-cylinder pressure cycle. This allows to have a non-intrusive estimation of cylinder pressure and a real time evaluation of combustion quality. The structure of the model and the training procedure is outlined in the paper. A possible combustion controller using the information extracted from the crankshaft speed information is also proposed. The application of the neural network model is demonstrated on a single-cylinder spark ignition engine tested in a wide range of speeds and loads. Results confirm that a good estimation of some combustion pressure parameters can be obtained by means of a suitable processing of crankshaft speed signal.

  2. Measurement crankshaft angular speed of an OM403 engine

    Directory of Open Access Journals (Sweden)

    Biočanin Stojko

    2017-01-01

    Full Text Available In this paper, the methodology of the measurement of the angular speed of the crankshaft of a ten-cylinder diesel OM403 engine is presented, with regular and irregular engine operation. The angular velocity was measured under laboratory conditions, on already installed measuring equipment from the laboratory and on the break of a well known brand-Schenck, by using an optoelectronic incremental rotary encoder, a data acquisition module and the LabVIEW software for synchronization and management of the measuring equipment. The goal of this paper is to give a practical contribution to researches of measuring of crankshaft angular speed of the crankshaft engine OM 403.

  3. The effect of tip speed ratio on a vertical axis wind turbine at high Reynolds numbers

    Science.gov (United States)

    Parker, Colin M.; Leftwich, Megan C.

    2016-05-01

    This work visualizes the flow surrounding a scaled model vertical axis wind turbine at realistic operating conditions. The model closely matches geometric and dynamic properties—tip speed ratio and Reynolds number—of a full-size turbine. The flow is visualized using particle imaging velocimetry (PIV) in the midplane upstream, around, and after (up to 4 turbine diameters downstream) the turbine, as well as a vertical plane behind the turbine. Time-averaged results show an asymmetric wake behind the turbine, regardless of tip speed ratio, with a larger velocity deficit for a higher tip speed ratio. For the higher tip speed ratio, an area of averaged flow reversal is present with a maximum reverse flow of -0.04U_∞. Phase-averaged vorticity fields—achieved by syncing the PIV system with the rotation of the turbine—show distinct structures form from each turbine blade. There were distinct differences in results by tip speed ratios of 0.9, 1.3, and 2.2 of when in the cycle structures are shed into the wake—switching from two pairs to a single pair of vortices being shed—and how they convect into the wake—the middle tip speed ratio vortices convect downstream inside the wake, while the high tip speed ratio pair is shed into the shear layer of the wake. Finally, results show that the wake structure is much more sensitive to changes in tip speed ratio than to changes in Reynolds number.

  4. Rotor aerodynamic power limits at low tip speed ratio using CFD

    DEFF Research Database (Denmark)

    Mikkelsen, Robert Flemming; Sarmast, Sasan; Henningson, Dan

    2014-01-01

    . In the present work we study in detail, using a CFD actuator line model, the flow behavior for rotors at small tip speed ratios. It is shown that the excessive swirl appearing towards the rotor center at small tip speed ratios generates vortex breakdown, causing a recirculating zone in the wake that limits...

  5. Intelligent Multiobjective Slip and Speed Ratio Control of a Novel Dual-Belt Continuously Variable Transmission for Automobiles

    Directory of Open Access Journals (Sweden)

    Zhengchao Xie

    2014-01-01

    Full Text Available Van Doorne’s continuously variable transmission (CVT is the most popular CVT design for automotive transmission, but it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt CVT, a novel dual-belt Van Doorne’s CVT (DBVCVT system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors. This paper, based on the published analytical model and test rig of DBVCVT, further proposes an intelligent multiobjective fuzzy controller for slip and speed ratio control of DBVCVT. The controller aims to safely control the clamping forces of both the primary and the secondary pulleys in order to improve the transmission efficiency, achieve the accurate speed ratio, and avoid the belt slip under different engine loads and vehicle speeds. The slip, speed ratio, and transmission efficiency dynamics of DBVCVT are firstly analyzed and modeled in this paper. With the aid of a flexible objective function, the analytical model, and fuzzy logic, a Pareto rule base for fuzzy controller is developed for multiobjective DBVCVT control. Experimental results show that the proposed controller for slip and speed ratio regulation of DBVCVT is effective and performs well under different user-defined weights.

  6. An investigation into the RCCI engine operation under low load and its achievable operational range at different engine speeds

    International Nuclear Information System (INIS)

    Wang, Yifeng; Zhu, ZhongWen; Yao, Mingfa; Li, Tie; Zhang, Weijing; Zheng, Zunqing

    2016-01-01

    Highlights: • The response of allowable RCCI operating range to engine speed variation is studied. • The RCCI and diesel LTC engine operations at are compared at low engine load. • The potential of expanding RCCI operating range at low engine speed is explored. - Abstract: Reactivity controlled compression ignition (RCCI) is demonstrated as a promising combustion strategy to achieve high efficiency and clean combustion. However, less effort has been devoted to examine the achievable RCCI operational range over a wide range of engine speed. In addition, previous studies have found that superior EGR rate and high diesel/gasoline fuel ratio are required to ease the extension of the low-load operating range of RCCI regime. Even then, relatively high CO and HC (unburned hydrocarbon) emissions and the accompanying fuel con-sum ption penalty still remain a problem to be resolved. Therefore, in this work the potential of diesel-fueled LTC to achieve simultaneously low NOx and soot emissions while maintaining high thermal efficiency at low load (IMEP ≈0.23–0.26 MPa) is investigated and compared with the gasoline/diesel RCCI strategy. The results show that the diesel LTC operation can yield slightly higher soot and NOx emissions (soot: 0.002 g/kW h, NOx: 0.446 g/kW h), but CO and HC emissions as well as the fuel consumption are much lower than the RCCI strategy, implying the diesel LTC regime may be more suitable for low-load operations. In addition, the RCCI operational range at speeds ranging from 900 to 2500 r/min is determined, the results show that the maximum achievable load (IMEP) increases with an increase in speed, and a maximum IMEP of 1.2 MPa can be achieved at an engine speed of 2300 r/min. Ultra-low NOx and soot emissions (soot < 0.003 g/kW h, NOx < 0.4 g/kW h) can be achieved under the maximum loading conditions at each speed investigated. However, high levels of CO and HC emissions still remain a big problem to be solved. The lowest fuel consumption

  7. A prediction model for wind speed ratios at pedestrian level with simplified urban canopies

    Science.gov (United States)

    Ikegaya, N.; Ikeda, Y.; Hagishima, A.; Razak, A. A.; Tanimoto, J.

    2017-02-01

    The purpose of this study is to review and improve prediction models for wind speed ratios at pedestrian level with simplified urban canopies. We adopted an extensive database of velocity fields under various conditions for arrays consisting of cubes, slender or flattened rectangles, and rectangles with varying roughness heights. Conclusions are summarized as follows: first, a new geometric parameter is introduced as a function of the plan area index and the aspect ratio so as to express the increase in virtual density that causes wind speed reduction. Second, the estimated wind speed ratios in the range 0.05 coefficients between the wind speeds averaged over the entire region, and the front or side region values are larger than 0.8. In contrast, in areas where the influence of roughness elements is significant, such as behind a building, the wind speeds are weakly correlated.

  8. METHOD OF CONVERSION OF HIGH- AND MIDDLE-SPEED DIESEL ENGINES INTO GAS DIESEL ENGINES

    Directory of Open Access Journals (Sweden)

    Mikhail G. Shatrov

    2017-12-01

    Full Text Available The paper aims at the development of fuel supply and electronic control systems for boosted high- and middle-speed transport engines. A detailed analysis of different ways of converting diesel engine to operate on natural gas was carried out. The gas diesel process with minimized ignition portion of diesel fuel injected by the Common Rail (CR system was selected. Electronic engine control and modular gas feed systems which can be used both on high- and middle-speed gas diesel engines were developed. Also diesel CR fuel supply systems were developed in cooperation with the industrial partner, namely, those that can be mounted on middle-speed diesel and gas diesel engines. Electronic control and gas feed systems were perfected using modeling and engine tests. The high-speed diesel engine was converted into a gas diesel one. After perfection of the gas feed and electronic control systems, bench tests of the high-speed gas diesel engine were carried out showing a high share of diesel fuel substitution with gas, high fuel efficiency and significant decrease of NOх and СО2 emissions.

  9. 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.

  10. Numerical Study on the Effect of Swept Blade on the Aerodynamic Performance of Wind Turbine at High Tip Speed Ratio

    International Nuclear Information System (INIS)

    Zuo, H M; Liu, C; Yang, H; Wang, F

    2016-01-01

    The current situation is that the development of high speed wind energy saturates gradually, therefore, it is highly necessary to develop low speed wind energy. This paper, based on a specific straight blade and by using Isight, a kind of multidiscipline optimization software, which integrates ICEM (Integrated Computer Engineering and Manufacturing) and CFD (Computational Fluid Dynamics) software, optimizes the blade stacking line (the centers of airfoil from blade root to tip) and acquires the optimization swept blade shape. It is found that power coefficient C p of swept blade is 3.2% higher than that of straight blade at the tip speed ratio of 9.82, that the thrust of swept blade receives is obviously less than that of straight blade. Inflow angle of attack and steam line on the suction of the swept and straight blade are also made a comparison. (paper)

  11. Performance and emission characteristics of LPG powered four stroke SI engine under variable stroke length and compression ratio

    International Nuclear Information System (INIS)

    Ozcan, Hakan; Yamin, Jehad A.A.

    2008-01-01

    A computer simulation of a variable stroke length, LPG fuelled, four stroke, single cylinder, water cooled spark ignition engine was done. The engine capacity was varied by varying the stroke length of the engine, which also changed its compression ratio. The simulation model developed was verified with experimental results from the literature for both constant and variable stroke engines. The performance of the engine was simulated at each stroke length/compression ratio combination. The simulation results clearly indicate the advantages and utility of variable stroke engines in fuel economy and power issues. Using the variable stroke technique has significantly improved the engine's performance and emission characteristics within the range studied. The brake torque and power have registered an increase of about 7-54% at low speed and 7-57% at high speed relative to the original engine design and for all stroke lengths and engine speeds studied. The brake specific fuel consumption has registered variations from a reduction of about 6% to an increase of about 3% at low speed and from a reduction of about 6% to an increase of about 8% at high speed relative to the original engine design and for all stroke lengths and engine speeds studied. On the other hand, an increase of pollutants of about 0.65-2% occurred at low speed. Larger stroke lengths resulted in a reduction of the pollutants level of about 1.5% at higher speeds. At lower stroke lengths, on the other hand, an increase of about 2% occurred. Larger stroke lengths resulted in increased exhaust temperature and, hence, make the exhaust valve work under high temperature

  12. The Effects of Engine Speed and Mixture Temperature on the Knocking Characteristics of Several Fuels

    Science.gov (United States)

    Lee, Dana W

    1940-01-01

    Six 100-octane and two 87-octane aviation engine fuels were tested in a modified C.F.R. variable-compression engine at 1,500, 2,000 and 2,500 rpm. The mixture temperature was raised from 50 to 300 F in approximately 50 degree steps and, at each temperature, the compression ratio was adjusted to give incipient knock as shown by a cathode ray indicator. The results are presented in tabular form. The results are analyzed on the assumption that the conditions which determine whether a given fuel will knock are the maximum values of density and temperature reached by the burning gases. A maximum permissible density factor, proportional to the maximum density of the burning gases just prior to incipient knock, and the temperature of the burning gases at that time were computed for each of the test conditions. Values of the density factors were plotted against the corresponding end-gas temperatures for the three engine speeds and also against engine speed for several and end-gas temperatures. The maximum permissible density factor varied only slightly with engine speed but decreased rapidly with an increase in the end-gas temperature. The effect of changing the mixture temperature was different for fuels of different types. The results emphasize the desirability of determining the anti knock values of fuels over a wide range of engine and intake-air conditions rather that at a single set of conditions.

  13. Rotor aerodynamic power limits at low tip speed ratio using CFD

    International Nuclear Information System (INIS)

    Mikkelsen, Robert F; Sarmast, Sasan; Henningson, Dan; Sørensen, Jens N

    2014-01-01

    When investigating limits of rotor aerodynamic models, the Betz limit serves as a solid marker of an upper limit which no model should be able to exceed. A century ago Joukowsky (1912) proposed a rotor aerodynamic model utilizing a rotating actuator disc with a constant circulation. This model has since then been the subject of much controversy as it predicts a power performance that for all tip speed ratios exceeds the Betz limit and which goes to infinity when the tip speed ratio goes to zero. Recently, it was demonstrated that the Joukowsky model is fully consistent with the inviscid Euler equations and that the apparent inconsistency partly can be explained by the lack of viscous effects (Sprensen and van Kuik [4]). However, even including a term to account for the effect of viscosity at small tip speed ratios, the model still predicts a power yield that exceeds the Betz limit. In the present work we study in detail, using a CFD actuator line model, the flow behavior for rotors at small tip speed ratios. It is shown that the excessive swirl appearing towards the rotor center at small tip speed ratios generates vortex breakdown, causing a recirculating zone in the wake that limits the power yield of the rotor. The appearance of vortex breakdown has a similar effect on the flow behavior as the vortex ring state that usually appears at higher tip speed ratios. Limits to where vortex breakdown might occur with tip speed ratio and rotor loading as parameter are investigated and presented in the paper. The limits found correspond to well-known criterion for vortex breakdown onset for swirling flows in general. By applying a criterion for vortex breakdown in combination with the general momentum theory, the power performance always stays below the Betz limit

  14. Alternative Observers for SI Engine Air/Fuel Ratio Control

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Poulsen, Jannik; Olsen, Mads Bruun

    1996-01-01

    In earlier work it has been shown that a nonlinear observer based on the use of the manifold pressure state equation and a nonlinear fuel film compensator can maintain accurate A/F ratio control during both steady state and transient operation. This observer may be called a manifold absolute pres...... engine control system designer with a variety of robust control systems which can easily be made redundant in order to satisfy newer engine emissions and diagnosis requirements and legislation...

  15. THE EFFECT OF VARIABLE COMPRESSION RATIO ON FUEL CONSUMPTION IN SPARK IGNITION ENGINES

    Directory of Open Access Journals (Sweden)

    Yakup SEKMEN

    2002-02-01

    Full Text Available Due to lack of energy sources in the world, we are obliged to use our current energy sources in the most efficient way. Therefore, in the automotive industry, research works to manufacture more economic cars in terms of fuelconsumption and environmental friendly cars, at the same time satisfying the required performance have been intensively increasing. Some positive results have been obtained by the studies, aimed to change the compression ratio according to the operating conditions of engine. In spark ignition engines in order to improve the combustion efficiency, fuel economy and exhaust emission in the partial loads, the compression ratio must be increased; but, under the high load and low speed conditions to prevent probable knock and hard running compression ratio must be decreased slightly. In this paper, various research works on the variable compression ratio with spark ignition engines, the effects on fuel economy, power output and thermal efficiency have been investigated. According to the results of the experiments performed with engines having variable compression ratio under the partial and mid-load conditions, an increase in engine power, a decrease in fuel consumption, particularly in partial loads up to 30 percent of fuel economy, and also severe reductions of some exhaust emission values were determined.

  16. Alvar engine. An engine with variable compression ratio. Experiments and tests

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Olof

    1998-09-01

    This report is focused on tests with Variable Compression Ratio (VCR) engines, according to the Alvar engine principle. Variable compression ratio means an engine design where it is possible to change the nominal compression ratio. The purpose is to increase the fuel efficiency at part load by increasing the compression ratio. At maximum load, and maybe supercharging with for example turbocharger, it is not possible to keep a high compression ratio because of the knock phenomena. Knock is a shock wave caused by self-ignition of the fuel-air mix. If knock occurs, the engine will be exposed to a destructive load. Because of the reasons mentioned it would be an advantage if it would be possible to change the compression ratio continuously when the load changes. The Alvar engine provides a solution for variable compression ratio based on well-known engine components. This paper provides information about efficiency and emission characteristics from tests with two Alvar engines. Results from tests with a phase shift mechanism (for automatic compression ratio control) for the Alvar engine are also reviewed Examination paper. 5 refs, 23 figs, 2 tabs, 5 appendices

  17. Current switching ratio optimization using dual pocket doping engineering

    Science.gov (United States)

    Dash, Sidhartha; Sahoo, Girija Shankar; Mishra, Guru Prasad

    2018-01-01

    This paper presents a smart idea to maximize current switching ratio of cylindrical gate tunnel FET (CGT) by growing pocket layers in both source and channel region. The pocket layers positioned in the source and channel of the device provides significant improvement in ON-state and OFF-state current respectively. The dual pocket doped cylindrical gate TFET (DP-CGT) exhibits much superior performance in term of drain current, transconductance and current ratio as compared to conventional CGT, channel pocket doped CGT (CP-CGT) and source pocket doped CGT (SP-CGT). Further, the current ratio has been optimized w.r.t. width and instantaneous position both the pocket layers. The much improved current ratio and low power consumption makes the proposed device suitable for low-power and high speed application. The simulation work of DP-CGT is done using 3D Sentaurus TCAD device simulator from Synopsys.

  18. New high expansion ratio gasoline engine for the TOYOTA hybrid system. Improving engine efficiency with high expansion ratio cycle; Hybrid system yo kobochohi gasoline engine. Kobochohi cycle ni yoru engine no kokoritsuka

    Energy Technology Data Exchange (ETDEWEB)

    Hirose, K; Takaoka, T; Ueda, T; Kobayashi, Y [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    50% reduction of CO2 and fuel consumption have been achieved with the newly developed gasoline engine for the Toyota Hybrid System. This is achieved due to the combination of electric motors and the internal combustion engine which is optimized in the size, swept volume and heat cycle. By delaying the intake valve close timing a high expansion ratio (13.5:1) cycle has been realized. Electricmotor assist enable to cut the maximum engine speed, and friction loss. A best fuel consumption figure better than 230 g/kWh has been achieved. Elimination of lightload firing, motor assisted quick start and improvement of catalyst warm up makes to achieve the clean emission level such as 1/10 of Japanese `78 regulation limit. 10 refs., 16 figs., 1 tab.

  19. Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

    Science.gov (United States)

    Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

    1972-01-01

    The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

  20. Tamanu oil. An alternative fuel for variable compression ratio engine

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Mohan T. [SASTRA Univ., Thanjavur, Tamilnadu (India). Dept. of Mechanical Engineering; Kandasamy, Murugumohan Kumar K. [Pavendar Bharathidasan College of Engineering and Technology, Trichy, Tamilnadu (India). Dept. of Mechanical Engineering

    2012-11-01

    Biodiesel can be produced from vegetable oils and also from waste fats. Biodiesel is a monoalkyl- ester of long chain fatty acids derived from renewable feedstock such as vegetable oils by transesterification process. The esterified cotton seed oil, pungam oil, rice bran oil, and tamanu oil are chosen as the alternative fuels. Among these oils, tamanu oil is considered for the first time as an alternative fuel. An experiment is conducted to obtain the operating characteristics of the variable compression ratio (VCR) engine run by chosen esterified oils, and the results are compared with esterified tamanu oil. From the comparison of results, it is inferred that the engine performance is improved with significant reduction in emissions for the chosen oils without any engine modification. The effective compression ratio can be fixed based on the experimental results obtained in the engine since the findings of the present research work infer that the biodiesel obtained from tamanu oil is a promising alternative fuel for direct-injection four-stroke VCR engine. (orig.)

  1. Optimization of suitable ethanol blend ratio for motorcycle engine using response surface method.

    Science.gov (United States)

    Chen, Yu-Liang; Chen, Suming; Tsai, Jin-Ming; Tsai, Chao-Yin; Fang, Hsin-Hsiung; Yang, I-Chang; Liu, Sen-Yuan

    2012-01-01

    In view of energy shortage and air pollution, ethanol-gasoline blended fuel used for motorcycle engine was studied in this work. The emissions of carbon monoxide (CO), nitrogen oxides (NO(X)) and engine performance of a 125 cc four-stroke motorcycle engine with original carburetor using ethanol-gasoline fuels were investigated. The model of three-variable Box Behnken design (BBD) was used for experimental design, the ethanol blend ratios were prepared at 0, 10, 20 vol%; the speeds of motorcycle were selected as 30, 45, 60 km/h; and the throttle positions were set at 30, 60, 90 %. Both engine performance and air pollutant emissions were then analyzed by response surface method (RSM) to yield optimum operation parameters for tolerable pollutant emissions and maximum engine performance. The RSM optimization analysis indicated that the most suitable ethanol-gasoline blended ratio was found at the range of 3.92-4.12 vol% to yield a comparable fuel conversion efficiency, while considerable reductions of exhaust pollutant emissions of CO (-29 %) and NO(X) (-12 %) when compared to pure gasoline fuel. This study demonstrated low ethanol-gasoline blended fuels could be used in motorcycle carburetor engines without any modification to keep engine power while reducing exhaust pollutants.

  2. Benefits of sequential turbocharging in improving high torque/low speed operation of medium speed diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Danyluk, P.; Gutoski, G. [Coltec Industries Inc., Fairbanks Morse Engine Division (United States); Chen, S.K. [PEI Consultants (United States)

    1998-12-31

    This paper describes the benefits of sequential turbocharging in improving the operating envelope of a medium speed diesel engine. In particular, the high torque, low speed performance envelope can be greatly extended over that of a standard medium speed engine and, in addition, can offer improved operating range over what has been achieved with compressor air bypass/waste gate systems. This paper compares the three approaches on the basis of possible operating envelopes for a specific application, the new U.S. Navy LPD-17 amphibious assault ship, which has a very demanding requirement for high torque at low engine speed and low ambient temperatures. Comparison is made to the earlier approach to extend the operating envelope on the U.S. Navy LSD-41 class engines. The LSD-41 fleet has been in service since 1985 running with a compressor air bypass system developed jointly by Lockheed Shipyard and Coltec Industries for the U.S. Navy. (au)

  3. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Science.gov (United States)

    2011-01-03

    ... [Docket No. NHTSA-2007-26851] Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter... occupants. IIHS stated that on-board electronic engine control modules (ECM) will maintain the desired speed... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of...

  4. Combustion engine variable compression ratio apparatus and method

    Science.gov (United States)

    Lawrence,; Keith, E [Peoria, IL; Strawbridge, Bryan E [Dunlap, IL; Dutart, Charles H [Washington, IL

    2006-06-06

    An apparatus and method for varying a compression ratio of an engine having a block and a head mounted thereto. The apparatus and method includes a cylinder having a block portion and a head portion, a piston linearly movable in the block portion of the cylinder, a cylinder plug linearly movable in the head portion of the cylinder, and a valve located in the cylinder plug and operable to provide controlled fluid communication with the block portion of the cylinder.

  5. Combustion in a High-Speed Compression-Ignition Engine

    Science.gov (United States)

    Rothrock, A M

    1933-01-01

    An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur. The results show that by increasing the air temperature during injection the start of combustion can be forced to take place during injection and so prevent detonation from occurring. It is shown that the rate of fuel injection does not in itself control the rate of combustion.

  6. Oracle Exalytics: Engineered for Speed-of-Thought Analytics

    Directory of Open Access Journals (Sweden)

    Gabriela GLIGOR

    2011-12-01

    Full Text Available One of the biggest product announcements at 2011's Oracle OpenWorld user conference was Oracle Exalytics In-Memory Machine, the latest addition to the "Exa"-branded suite of Oracle-Sun engineered software-hardware systems. Analytics is all about gaining insights from the data for better decision making. However, the vision of delivering fast, interactive, insightful analytics has remained elusive for most organizations. Most enterprise IT organizations continue to struggle to deliver actionable analytics due to time-sensitive, sprawling requirements and ever tightening budgets. The issue is further exasperated by the fact that most enterprise analytics solutions require dealing with a number of hardware, software, storage and networking vendors and precious resources are wasted integrating the hardware and software components to deliver a complete analytical solution. Oracle Exalytics Business Intelligence Machine is the world’s first engineered system specifically designed to deliver high performance analysis, modeling and planning. Built using industry-standard hardware, market-leading business intelligence software and in-memory database technology, Oracle Exalytics is an optimized system that delivers answers to all your business questions with unmatched speed, intelligence, simplicity and manageability.

  7. Wind-tunnel modelling of the tip-speed ratio influence on the wake evolution

    Science.gov (United States)

    Stein, Victor P.; Kaltenbach, Hans-Jakob

    2016-09-01

    Wind-tunnel measurements on the near-wake evolution of a three bladed horizontal axis wind turbine model (HAWT) in the scale 1:O(350) operating in uniform flow conditions and within a turbulent boundary layer at different tip speed ratios are presented. Operational conditions are chosen to exclude Reynolds number effects regarding the turbulent boundary layer as well as the rotor performance. Triple-wire anemometry is used to measure all three velocity components in the mid-vertical and mid-horizontal plane, covering the range from the near- to the far-wake region. In order to analyse wake properties systematically, power and thrust coefficients of the turbine were measured additionally. It is confirmed that realistic modelling of the wake evolution is not possible in a low-turbulence uniform approach flow. Profiles of mean velocity and turbulence intensity exhibit large deviations between the low-turbulence uniform flow and the turbulent boundary layer, especially in the far-wake region. For nearly constant thrust coefficients differences in the evolution of the near-wake can be identified for tip speed ratios in the range from 6.5 to 10.5. It is shown that with increasing downstream distances mean velocity profiles become indistinguishable whereas for turbulence statistics a subtle dependency on the tip speed ratio is still noticeable in the far-wake region.

  8. Speed limiter integrated fatigue analyzer (SLIFA) for speed and fatigue control on diesel engine truck and bus

    Science.gov (United States)

    Wahyudi, Haris; Pranoto, Hadi; Leman, A. M.; Sebayang, Darwin; Baba, I.

    2017-09-01

    Every second, the number of road traffic deaths is increased globally with millions more sustaining severe injuries and living with long-term adverse health consequences. Jakarta alone in year 2015 had recorded 556 people died due to road accidents, approximately reached 6.231 road accident cases. The identified major contributory factors of such unfortunate events are both driver fatigue and over speeding habit especially related to the driving of truck and bus. This paper presents the idea on how to control the electronic system from input fuel system of injection pump and the combustion chamber engine will control the valve solenoid in injection pump which can lock and fuel will stop for moment, and speed limit can be success, by using sensor heart rate we can input reduce speed limit when fatigue detection driver. Integration process this tool can be relevant when Speed Limiter Integrated Fatigue Analyser (SLIFA) trial in the diesel engine for truck and bus, the result of this research Speed Limiter Integrated Fatigue Analyser (SLIFA) able to control speed of diesel engine for truck and bus almost 30km/h, 60km/h, and until 70 km/h. The installation of the sensor heart rate as the input speed limit SLIFA would work when the driver is detected to be in the fatigue condition. We make Speed Limiter Integrated Fatigue Analyser (SLIFA) for control and monitoring system for diesel engine in truck and bus. Speed Limiter Integrated Fatigue Analyser (SLIFA) system can save the historical of the speed record, fatigue, rpm, and body temperature of the driver.

  9. Research on H2 speed governor for diesel engine of marine power station

    Science.gov (United States)

    Huang, Man-Lei

    2007-09-01

    The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H2 speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.

  10. Efficient, Low Pressure Ratio Propulsor for Gas Turbine Engines

    Science.gov (United States)

    Gallagher, Edward J. (Inventor); Monzon, Byron R. (Inventor)

    2018-01-01

    A gas turbine engine includes a bypass flow passage that has an inlet and defines a bypass ratio in a range of approximately 8.5 to 13.5. A fan is arranged within the bypass flow passage. A first turbine is a 5-stage turbine and is coupled with a first shaft, which is coupled with the fan. A first compressor is coupled with the first shaft and is a 3-stage compressor. A second turbine is coupled with a second shaft and is a 2-stage turbine. The fan includes a row of fan blades that extend from a hub. The row includes a number (N) of the fan blades, a solidity value (R) at tips of the fab blades, and a ratio of N/R that is from 14 to 16.

  11. Experimental Comparison of Speed : Fuel-flow and Speed-area Controls on a Turbojet Engine for Small Step Disturbances

    Science.gov (United States)

    Wenzel, L M; Hart, C E; Craig, R T

    1957-01-01

    Optimum proportional-plus-integral control settings for speed - fuel-flow control, determined by minimization of integral criteria, correlated well with analytically predicted optimum settings. Engine response data are given for a range of control settings around the optimum. An inherent nonlinearity in the speed-area loop necessitated the use of nonlinear controls. Response data for two such nonlinear control schemes are presented.

  12. General momentum theory for wind turbines at low tip speed ratios

    DEFF Research Database (Denmark)

    Sørensen, Jens Nørkær; van Kuik, Gijs A. M.

    2011-01-01

    General momentum theory is used to study the behaviour of the ‘classical’ free vortex wake model of Joukowsky. This model has recently attained considerable attention as it shows the possibility of achieving a power performance that greatly exceeds the Lanchester‐Betz limit for rotors running...... at low tip speed ratios. This behaviour is confirmed even when including the effect of a centre vortex, allowing azimuthal velocities and the associated radial pressure gradient to be taken into account in the axial momentum balance without any simplifying assumptions. It is shown that the most likely...

  13. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Science.gov (United States)

    2010-07-01

    ... cylinders having an internal diameter of 13.0 cm and a 15.5 cm stroke length, the rounded displacement would... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes...

  14. Rebound effects from speed and acceleration in electric and internal combustion engine cars: An empirical and conceptual investigation

    International Nuclear Information System (INIS)

    Galvin, Ray

    2016-01-01

    Highlights: • Vehicle rebound effects have been investigated for distance but not speed. • We investigate speed rebounds for an e- and an ICE-car in controlled lab tests. • We develop a mathematical model to include these with distance rebound effects. • The e-car shows 20% speed rebound comparing 1975 and modern driving styles. • The ICE-car shows speed rebound due to lock-in from auto gear ratios. - Abstract: Rebound effect studies of road vehicle travel focus mostly on increases in distance traveled after increases in energy efficiency. Average journeying speed also increases with energy efficiency, but rebound studies avoid quantifying speed-related rebound effects. This may underestimate rebound effects by around 60%. This study offers a first attempt to show how increases in speed and acceleration contribute to rebound effects, and how these can be quantified. Its empirical data is dynamometer test results for a plug-in electric car and an internal combustion engine (ICE) pick-up van with automatic transmission, each on the WLTP and NEDC drive cycles, representing driving styles from today and 1975 respectively. Rebound effects are estimated by comparing the WLTP and NEDC results, using typical 1975 energy efficiencies for the NEDC. The electric car shows a 20.5% speed rebound effect, and a mathematical development sets out how speed rebound effects can be included in traditional rebound effect analyses. Results for the ICE-vehicle do not allow a direct rebound effect estimate due to wasteful engine revving on the NEDC and wrong gear ratios for sedate travel. However, this can be seen as a form of ‘transformational’ rebound effect, where vehicle design locks drivers into fast driving styles.

  15. The Effect of Humidity on the Knock Behavior in a Medium BMEP Lean-Burn High-Speed Gas Engine

    NARCIS (Netherlands)

    van Essen, Vincent Martijn; Gersen, Sander; van Dijk, Gerco; Mundt, Torsten; Levinsky, Howard

    2016-01-01

    The effects of air humidity on the knock characteristics of fuels are investigated in a lean-burn, high-speed medium BMEP engine fueled with a CH4 + 4.7 mole% C3H8 gas mixture. Experiments are carried out with humidity ratios ranging from 4.3 to 11 g H2O/kg dry air. The measured pressure profiles at

  16. Engineering feasibility of tight aspect ratio Tokamak (spherical torus) reactors

    International Nuclear Information System (INIS)

    Peng, Y-K.M.; Hicks, J.B.

    1990-01-01

    Engineering solutions are identified and analyzed for key high-power-density components of tight aspect ratio tokamak reactors (spherical torus reactors). The potentially extreme divertor heat loads can be reduced to about 3 MW/m 2 in expanded divertors using coils inside the demountable toroidal field coils. Given the long and narrow divertor channels, gaseous divertor targets become possible, which eliminate sputtering and increase the divertor life. The unshielded centre conductor post (CCP) of the toroidal field coil can be made of a single dispersion strengthened copper conductor cooled by high-velocity pressurized water to maintain acceptable copper temperature and strength. Damage and activation of the CCP at a neutron fluence of 10 MW-a/m 2 are also tolerable. Annual replacement of the centre post, the divertor assemblies and the blanket can be accomplished with vertical access for all torus components, which are modularized to reduce size and weight. The technical requirements of these solutions are shown to be comparable with, if not less demanding than, those estimated for conventional tokamak reactors. (author)

  17. Variable speed gas engine-driven air compressor system

    Science.gov (United States)

    Morgan, J. R.; Ruggles, A. E.; Chen, T. N.; Gehret, J.

    1992-11-01

    Tecogen Inc. and Ingersoll-Rand Co. as a subcontractor have designed a nominal 150-hp gas engine-driven air compressor utilizing the TECODRIVE 8000 engine and the Ingersoll-Rand 178.5-mm twin screw compressor. Phase 1 included the system engineering and design, economic and applications studies, and a draft commercialization plan. Phase 2 included controls development, laboratory prototype construction, and performance testing. The testing conducted verified that the compressor meets all design specifications.

  18. Coal-fueled high-speed diesel engine development: Task 2, Market assessment and economic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kakwani, R. M.; Wilson, Jr., R. P.; Winsor, R. E.

    1991-12-01

    Based on the preliminary coal engine design developed, this task was conducted to identify the best opportunity(s) to enter the market with the future coal-fueled, high-speed diesel engine. The results of this market and economic feasibility assessment will be used to determine what specific heavy duty engine application(s) are most attractive for coal fuel, and also define basic economic targets for the engine to be competitive.

  19. Speed

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Speed. The rate of information transferred per second is the speed of the information. Measured in bits per second. Need for speed on the net: You-Tube phenomenon; IPTV; 3D Video telephony. Online gaming; HDTV.

  20. Energetic and exergetic analyses of a variable compression ratio spark ignition gas engine

    International Nuclear Information System (INIS)

    Javaheri, A.; Esfahanian, V.; Salavati-Zadeh, A.; Darzi, M.

    2014-01-01

    Highlights: • Effects of CR and λ on CNG SI ICE 1st and 2nd law analyses are experimentally studied. • The performance of pure methane and a real CNG are observed and compared. • The ratio of actual to Otto cycle thermal efficiencies is 0.78 for all cases. • At least 25.5% of destructed availability is due to combustion irreversibility. • With decrease in methane content, CNG shows more combustion irreversibility. - Abstract: Considering the significance of obtaining higher efficiencies from internal combustion engines (ICE) along with the growing role of natural gas as a fuel, the present work is set to explore the effects of compression ratio (CR hereafter) and air/fuel equivalence ratio (AFER hereafter) on the energy and exergy potentials in a gas-fueled spark ignition internal combustion engine. Experiments are carried out using a single cylinder, port injection, water cooled, variable compression ratio (VCR hereafter), spark ignition engine at a constant engine speed of 2000 rpm. The study involves CRs of 12, 14 and 16 and 10 AFERs between 0.8 and 1.25. Pure methane is utilized for the analysis. In addition, a natural gas blend with the minimum methane content among Iranian gas sources is also tested in order to investigate the effect of real natural gas on findings. The energy analysis involves input fuel power, indicated power and losses due to high temperature of exhaust gases and their unburned content, blow-by and heat loss. The exergy analysis is carried out for availability input and piston, exhaust, and losses availabilities along with destructed entropy. The analysis indicates an increase in the ratio of thermo-mechanical exhaust availability to fuel availability by CR with a maximum near stoichiometry, whereas it is shown that chemical exhaust exergy is not dependent on CR and reduces with AFER. In addition, it is indicated that the ratio of actual cycle to Otto cycle thermal efficiencies is about constant (about 0.784) with changing CR

  1. A trident dithienylethene-perylenemonoimide dyad with super fluorescence switching speed and ratio

    Science.gov (United States)

    Li, Chong; Yan, Hui; Zhao, Ling-Xi; Zhang, Guo-Feng; Hu, Zhe; Huang, Zhen-Li; Zhu, Ming-Qiang

    2014-12-01

    Photoswitchable fluorescent diarylethenes are promising in molecular optical memory and photonic devices. However, the performance of current diarylethenes is far from satisfactory because of the scarcity of high-speed switching capability and large fluorescence on-off ratio. Here we report a trident perylenemonoimide dyad modified by triple dithienylethenes whose photochromic fluorescence quenching ratio at the photostationary state exceeds 10,000 and the fluorescence quenching efficiency is close to 100% within seconds of ultraviolet irradiation. The highly sensitive fluorescence on/off switching of the trident dyad enables recyclable fluorescence patterning and all-optical transistors. The prototype optical device based on the trident dyad enables the optical switching of incident light and conversion from incident light wavelength to transmitted light wavelength, which is all-optically controlled, reversible and wavelength-convertible. In addition, the trident dyad-staining block copolymer vesicles are observed via optical nanoimaging with a sub-100 nm resolution, portending a potential prospect of the dithienylethene dyad in super-resolution imaging.

  2. Performance and emission of generator Diesel engine using methyl esters of palm oil and diesel blends at different compression ratio

    Science.gov (United States)

    Aldhaidhawi, M.; Chiriac, R.; Bădescu, V.; Pop, H.; Apostol, V.; Dobrovicescu, A.; Prisecaru, M.; Alfaryjat, A. A.; Ghilvacs, M.; Alexandru, A.

    2016-08-01

    This study proposes engine model to predicate the performance and exhaust gas emissions of a single cylinder four stroke direct injection engine which was fuelled with diesel and palm oil methyl ester of B7 (blends 7% palm oil methyl ester with 93% diesel by volume) and B10. The experiment was conducted at constant engine speed of 3000 rpm and different engine loads operations with compression ratios of 18:1, 20:1 and 22:1. The influence of the compression ratio and fuel typeson specific fuel consumption and brake thermal efficiency has been investigated and presented. The optimum compression ratio which yields better performance has been identified. The result from the present work confirms that biodiesel resulting from palm oil methyl ester could represent a superior alternative to diesel fuel when the engine operates with variable compression ratios. The blends, when used as fuel, result in a reduction of the brake specific fuel consumption and brake thermal efficiency, while NOx emissions was increased when the engine is operated with biodiesel blends.

  3. 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...

  4. Laser Velocimeter Measurements in the Pump of an Automotive Torque Converter Part I – Effect of Speed Ratio

    Directory of Open Access Journals (Sweden)

    Steven B. Ainley

    2000-01-01

    Full Text Available A torque converter was tested at four turbine/pump rotational speed ratios (0.200, 0.400, 0.600, and 0.800 all with a constant pump rotational speed in order to determine the effect of speed ratio on the torque converter pump flow field. Laser velocimetry was used to measure three components of velocity within the pump and a shaft encoder was employed to record the instantaneous pump angular position. Shaft encoder information was correlated with measured velocities to develop flow field blade-to-blade profiles and vector plots. Measurements were obtained in both the pump mid- and exit planes for all four speed ratios. Results showed large separation regions and jet/wake flows throughout the pump. The midplane flow was found to have strong counter-clockwise secondary components and the exit plane flow had strong clockwise secondary components. Mass flows were calculated from the velocity data and were found to decrease as the speed ratio was increased. Also, the vorticity and slip factors were calculated from the experimental data and are included. The mid-plane slip factors compare favorably to those for conventional centrifugal pumps but less slip was present in the exit plane than the mid-plane. Neither the slip factor nor the vorticity were seen to be strongly affected by the speed ratio. Finally, the torque core-to-shell and blade-to-blade torque distributions are presented for both planes.

  5. Body Fineness Ratio as a Predictor of Maximum Prolonged-Swimming Speed in Coral Reef Fishes

    Science.gov (United States)

    Walker, Jeffrey A.; Alfaro, Michael E.; Noble, Mae M.; Fulton, Christopher J.

    2013-01-01

    The ability to sustain high swimming speeds is believed to be an important factor affecting resource acquisition in fishes. While we have gained insights into how fin morphology and motion influences swimming performance in coral reef fishes, the role of other traits, such as body shape, remains poorly understood. We explore the ability of two mechanistic models of the causal relationship between body fineness ratio and endurance swimming-performance to predict maximum prolonged-swimming speed (Umax) among 84 fish species from the Great Barrier Reef, Australia. A drag model, based on semi-empirical data on the drag of rigid, submerged bodies of revolution, was applied to species that employ pectoral-fin propulsion with a rigid body at U max. An alternative model, based on the results of computer simulations of optimal shape in self-propelled undulating bodies, was applied to the species that swim by body-caudal-fin propulsion at Umax. For pectoral-fin swimmers, Umax increased with fineness, and the rate of increase decreased with fineness, as predicted by the drag model. While the mechanistic and statistical models of the relationship between fineness and Umax were very similar, the mechanistic (and statistical) model explained only a small fraction of the variance in Umax. For body-caudal-fin swimmers, we found a non-linear relationship between fineness and Umax, which was largely negative over most of the range of fineness. This pattern fails to support either predictions from the computational models or standard functional interpretations of body shape variation in fishes. Our results suggest that the widespread hypothesis that a more optimal fineness increases endurance-swimming performance via reduced drag should be limited to fishes that swim with rigid bodies. PMID:24204575

  6. Effect of compression ratio, nozzle opening pressure, engine load, and butanol addition on nanoparticle emissions from a non-road diesel engine.

    Science.gov (United States)

    Maurya, Rakesh Kumar; Saxena, Mohit Raj; Rai, Piyush; Bhardwaj, Aashish

    2018-05-01

    Currently, diesel engines are more preferred over gasoline engines due to their higher torque output and fuel economy. However, diesel engines confront major challenge of meeting the future stringent emission norms (especially soot particle emissions) while maintaining the same fuel economy. In this study, nanosize range soot particle emission characteristics of a stationary (non-road) diesel engine have been experimentally investigated. Experiments are conducted at a constant speed of 1500 rpm for three compression ratios and nozzle opening pressures at different engine loads. In-cylinder pressure history for 2000 consecutive engine cycles is recorded and averaged data is used for analysis of combustion characteristics. An electrical mobility-based fast particle sizer is used for analyzing particle size and mass distributions of engine exhaust particles at different test conditions. Soot particle distribution from 5 to 1000 nm was recorded. Results show that total particle concentration decreases with an increase in engine operating loads. Moreover, the addition of butanol in the diesel fuel leads to the reduction in soot particle concentration. Regression analysis was also conducted to derive a correlation between combustion parameters and particle number emissions for different compression ratios. Regression analysis shows a strong correlation between cylinder pressure-based combustion parameters and particle number emission.

  7. Estimation of Engine Intake Air Mass Flow using a generic Speed-Density method

    Directory of Open Access Journals (Sweden)

    Vojtíšek Michal

    2014-10-01

    Full Text Available Measurement of real driving emissions (RDE from internal combustion engines under real-world operation using portable, onboard monitoring systems (PEMS is becoming an increasingly important tool aiding the assessment of the effects of new fuels and technologies on environment and human health. The knowledge of exhaust flow is one of the prerequisites for successful RDE measurement with PEMS. One of the simplest approaches for estimating the exhaust flow from virtually any engine is its computation from the intake air flow, which is calculated from measured engine rpm and intake manifold charge pressure and temperature using a generic speed-density algorithm, applicable to most contemporary four-cycle engines. In this work, a generic speed-density algorithm was compared against several reference methods on representative European production engines - a gasoline port-injected automobile engine, two turbocharged diesel automobile engines, and a heavy-duty turbocharged diesel engine. The overall results suggest that the uncertainty of the generic speed-density method is on the order of 10% throughout most of the engine operating range, but increasing to tens of percent where high-volume exhaust gas recirculation is used. For non-EGR engines, such uncertainty is acceptable for many simpler and screening measurements, and may be, where desired, reduced by engine-specific calibration.

  8. A modified time-of-flight method for precise determination of high speed ratios in molecular beams

    Energy Technology Data Exchange (ETDEWEB)

    Salvador Palau, A.; Eder, S. D., E-mail: sabrina.eder@uib.no; Kaltenbacher, T.; Samelin, B.; Holst, B. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); Bracco, G. [Department of Physics and Technology, University of Bergen, Allégaten 55, 5007 Bergen (Norway); CNR-IMEM, Department of Physics, University of Genova, V. Dodecaneso 33, 16146 Genova (Italy)

    2016-02-15

    Time-of-flight (TOF) is a standard experimental technique for determining, among others, the speed ratio S (velocity spread) of a molecular beam. The speed ratio is a measure for the monochromaticity of the beam and an accurate determination of S is crucial for various applications, for example, for characterising chromatic aberrations in focussing experiments related to helium microscopy or for precise measurements of surface phonons and surface structures in molecular beam scattering experiments. For both of these applications, it is desirable to have as high a speed ratio as possible. Molecular beam TOF measurements are typically performed by chopping the beam using a rotating chopper with one or more slit openings. The TOF spectra are evaluated using a standard deconvolution method. However, for higher speed ratios, this method is very sensitive to errors related to the determination of the slit width and the beam diameter. The exact sensitivity depends on the beam diameter, the number of slits, the chopper radius, and the chopper rotation frequency. We present a modified method suitable for the evaluation of TOF measurements of high speed ratio beams. The modified method is based on a systematic variation of the chopper convolution parameters so that a set of independent measurements that can be fitted with an appropriate function are obtained. We show that with this modified method, it is possible to reduce the error by typically one order of magnitude compared to the standard method.

  9. Bitumen/Water Emulsions as Fuels for High-Speed Ci Engines Preliminary Investigations

    DEFF Research Database (Denmark)

    Schramm, Jesper; Sigvardsen, R.; Forman, M.

    2003-01-01

    Mixtures of bitumen and water, are cheap fuel alternatives for combustion engines. There are, however, several problems that have to be solved before these fuels can be applied in high-speed diesel engines. These are: - emulsion break up due to high temperature or high shear stress in the injection...

  10. Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

    Science.gov (United States)

    Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

    2011-01-01

    NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

  11. Performance analysis of wind turbines at low tip-speed ratio using the Betz-Goldstein model

    International Nuclear Information System (INIS)

    Vaz, Jerson R.P.; Wood, David H.

    2016-01-01

    Highlights: • General formulations for power and thrust at any tip-speed ratio are developed. • The Joukowsky model for the blades is modified with specific vortex distributions. • Betz-Goldstein model is shown to be the most consistent at low tip-speed ratio. • The effects of finite blade number are assessed using tip loss factors. • Tip loss for finite blade number may complicate the vortex breakdown. - Abstract: Analyzing wind turbine performance at low tip-speed ratio is challenging due to the relatively high level of swirl in the wake. This work presents a new approach to wind turbine analysis including swirl for any tip-speed ratio. The methodology uses the induced velocity field from vortex theory in the general momentum theory, in the form of the turbine thrust and torque equations. Using the constant bound circulation model of Joukowsky, the swirl velocity becomes infinite on the wake centreline even at high tip-speed ratio. Rankine, Vatistas and Delery vortices were used to regularize the Joukowsky model near the centreline. The new formulation prevents the power coefficient from exceeding the Betz-Joukowsky limit. An alternative calculation, based on the varying circulation for Betz-Goldstein optimized rotors is shown to have the best general behavior. Prandtl’s approximation for the tip loss and a recent alternative were employed to account for the effects of a finite number of blades. The Betz-Goldstein model appears to be the only one resistant to vortex breakdown immediately behind the rotor for an infinite number of blades. Furthermore, the dependence of the induced velocity on radius in the Betz-Goldstein model allows the power coefficient to remain below Betz-Joukowsky limit which does not occur for the Joukowsky model at low tip-speed ratio.

  12. THE EFFECTS OF INCREASE THE COMPRESSION RATIO ON PERFORMANCE OF A DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    Adnan PARLAK

    2003-02-01

    Full Text Available An optimisation of the Diesel cycle has been performed for power output and thermal efficiency with respect to compression ratio for various extreme temperature ratio. The relation between compression ratio and extreme temperature ratio, which gives optimum performance is derived. As the compression ratio of the diesel engine is increased in comparison to the optimum value of the engine, it is shown that the performance of the engine is decreased. The experimental study agrees with these results. In this study, compression ratio of a single cylinder pre-combustion chamber variable compression ratio Ricardo E6 type engine with the optimum compression ratio of 18.20 was increased to 19.60. As a results of this increase, specific fuel consumption was increased about 8 % and brake thermal efficiency was decreased about 7.5 %.

  13. Variable Pitch Approach for Performance Improving of Straight-Bladed VAWT at Rated Tip Speed Ratio

    Directory of Open Access Journals (Sweden)

    Zhenzhou Zhao

    2018-06-01

    Full Text Available This paper presents a new variable pitch (VP approach to increase the peak power coefficient of the straight-bladed vertical-axis wind turbine (VAWT, by widening the azimuthal angle band of the blade with the highest aerodynamic torque, instead of increasing the highest torque. The new VP-approach provides a curve of pitch angle designed for the blade operating at the rated tip speed ratio (TSR corresponding to the peak power coefficient of the fixed pitch (FP-VAWT. The effects of the new approach are exploited by using the double multiple stream tubes (DMST model and Prandtl’s mathematics to evaluate the blade tip loss. The research describes the effects from six aspects, including the lift, drag, angle of attack (AoA, resultant velocity, torque, and power output, through a comparison between VP-VAWTs and FP-VAWTs working at four TSRs: 4, 4.5, 5, and 5.5. Compared with the FP-blade, the VP-blade has a wider azimuthal zone with the maximum AoA, lift, drag, and torque in the upwind half-cycle, and yields the two new larger maximum values in the downwind half-cycle. The power distribution in the swept area of the turbine changes from an arched shape of the FP-VAWT into the rectangular shape of the VP-VAWT. The new VP-approach markedly widens the highest-performance zone of the blade in a revolution, and ultimately achieves an 18.9% growth of the peak power coefficient of the VAWT at the optimum TSR. Besides achieving this growth, the new pitching method will enhance the performance at TSRs that are higher than current optimal values, and an increase of torque is also generated.

  14. Knock-Limited Performance of Triptane and 28-R Fuel Blends as Affected by Changes in Compression Ratio and in Engine Operating Variables

    Science.gov (United States)

    Brun, Rinaldo J.; Feder, Melvin S.; Fisher, William F.

    1947-01-01

    A knock-limited performance investigation was conducted on blends of triptane and 28-P fuel with a 12-cylinder, V-type, liquid-cooled aircraft engine of 1710-cubic-inch displacement at three compression ratios: 6.65, 7.93, and 9.68. At each compression ratio, the effect of changes in temperature of the inlet air to the auxiliary-stage supercharger and in fuel-air ratio were investigated at engine speeds of 2280 and. 3000 rpm. The results show that knock-limited engine performance, as improved by the use of triptane, allowed operation at both take-off and cruising power at a compression ratio of 9.68. At an inlet-air temperature of 60 deg F, an engine speed of 3000 rpm ; and a fuel-air ratio of 0,095 (approximately take-off conditions), a knock-limited engine output of 1500 brake horsepower was possible with 100-percent 28-R fuel at a compression ratio of 6.65; 20-percent triptane was required for the same power output at a compression ratio of 7.93, and 75 percent at a compression ratio of 9.68 allowed an output of 1480 brake horsepower. Knock-limited power output was more sensitive to changes in fuel-air ratio as the engine speed was increased from 2280 to 3000 rpm, as the compression ratio is raised from 6.65 to 9.68, or as the inlet-air temperature is raised from 0 deg to 120 deg F.

  15. A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

    Science.gov (United States)

    Hua, Wei; Miao, Lizhen; Zhang, Haibo; Huang, Jinquan

    2015-12-01

    A closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

  16. With power comes responsibility: motorcycle engine power and power-to-weight ratio in relation to accident risk.

    Science.gov (United States)

    Mattsson, Markus; Summala, Heikki

    2010-02-01

    Current European legislation allows the EU member states to restrict the maximum power output of motorcycles to 74 kW even though evidence supporting the limit is scarce and has produced mixed results-perhaps because motorcycle performance has been measured by engine displacement, not engine power, in most of the previous studies. This study investigates the relationship of motorcycle engine power and power-to-weight ratio to risk of fatal and nonfatal crashes in Finland. The fatality rate (number of fatal accidents/number of registered motorbikes) for riders of different ages riding bikes belonging to different power and power-to-weight ratio classes was examined using a comprehensive in-depth database. Data on nonfatal accidents were acquired from a Web questionnaire (N = 2708), which also served as a basis for estimating riders' annual mileage. Mileage data allowed the calculation of accident risk per kilometer ridden for bikes differing in power and power-to-weight ratio. The fatality risk per number of registered motorcycles and per kilometer ridden increases both with power and power-to-weight ratio, independently of rider's age. No relationship between performance and risk of a less severe crash was found. The pre-accident speed of the most powerful bikes was 20 km/h or more over the speed limit in a large proportion of the fatal accidents (odds ratio = 4.8 for > 75 kW motorbikes; odds ratio = 6.2 for > 0.3 kW/kg motorbikes). The risk of being involved in a fatal crash is higher among the riders of powerful motorcycles. However, it is not clear whether the results are related to the riding habits of the riders that choose the most powerful bikes available or whether the high risk is due to the properties of the bikes themselves. Therefore, further research is needed before considering legal limits on motorcycle performance.

  17. Minimum Specific Fuel Consumption of a Liquid-Cooled Multicylinder Aircraft Engine as Affected by Compression Ratio and Engine Operating Conditions

    Science.gov (United States)

    Brun, Rinaldo J.; Feder, Melvin S.; Harries, Myron L.

    1947-01-01

    An investigation was conducted on a 12-cylinder V-type liquid-cooled aircraft engine of 1710-cubic-inch displacement to determine the minimum specific fuel consumption at constant cruising engine speed and compression ratios of 6.65, 7.93, and 9.68. At each compression ratio, the effect.of the following variables was investigated at manifold pressures of 28, 34, 40, and 50 inches of mercury absolute: temperature of the inlet-air to the auxiliary-stage supercharger, fuel-air ratio, and spark advance. Standard sea-level atmospheric pressure was maintained at the auxiliary-stage supercharger inlet and the exhaust pressure was atmospheric. Advancing the spark timing from 34 deg and 28 deg B.T.C. (exhaust and intake, respectively) to 42 deg and 36 deg B.T.C. at a compression ratio of 6.65 resulted in a decrease of approximately 3 percent in brake specific fuel consumption. Further decreases in brake specific fuel consumption of 10.5 to 14.1 percent (depending on power level) were observed as the compression ratio was increased from 6.65 to 9.68, maintaining at each compression ratio the spark advance required for maximum torque at a fuel-air ratio of 0.06. This increase in compression ratio with a power output of 0.585 horsepower per cubic inch required a change from . a fuel- lend of 6-percent triptane with 94-percent 68--R fuel at a compression ratio of 6.65 to a fuel blend of 58-percent, triptane with 42-percent 28-R fuel at a compression ratio of 9.68 to provide for knock-free engine operation. As an aid in the evaluation of engine mechanical endurance, peak cylinder pressures were measured on a single-cylinder engine at several operating conditions. Peak cylinder pressures of 1900 pounds per square inch can be expected at a compression ratio of 9.68 and an indicated mean effective pressure of 320 pounds per square inch. The engine durability was considerably reduced at these conditions.

  18. Effect Of Compression Ratio On The Performance Of Diesel Engine At Different Loads.

    OpenAIRE

    Abhishek Reddy G; Nirmal Pratap Singh

    2015-01-01

    Variable compression ratio (VCR) technology has long been recognized as a method for improving the automobile engine performance, efficiency, fuel economy with reduced emission. The main feature of the VCR engine is to operate at different compression ratio, by changing the combustion chamber volume, depending on the vehicle performance needs .The need to improve the performance characteristics of the IC Engine has necessitated the present research. Increasing the compression rati...

  19. Multiroller Traction Drive Speed Reducer. Evaluation for Automotive Gas Turbine Engine

    Science.gov (United States)

    1982-06-01

    Speed is deLermined by a magnetic pickup on a toothed wheel . Gas turbine engine instrumunelLtiouu i -designed 1f0r measurement of specific fuel...buffer seal and the fluid--film bearing measured a maximum total runout of 0.038 mm (0.0015 in.) at low speed. At higher speeds, above 8000 rpm, the...maximum was 0.025 mm (0.001 in.) except near 10 000 rpm, where the oscilloscope indicated an excursion of 0.045 mm (0.0018 in.). This runout was within

  20. An Investigation of the Composition of the Flow in and out of a Two-Stroke Diesel Engine and Air Consumption Ratio

    Directory of Open Access Journals (Sweden)

    Mirko Grljušić

    2017-06-01

    Full Text Available The aim of this research was to investigate the mass, substance and energy flow through two-stroke low speed Diesel engines. For this reason, a zero-dimensional model of the combustion in the engine was developed with a calculated amount and composition of exhaust gases. Due to the large amount of oxygen in the exhaust gases, a ratio of real air consumption and stoichiometric amount of air required for combustion of injected fuel was set. The calculated ratio showed that the engine consumed four times more air than needed for combustion in AFRstoich. In this work, this was called the Air Consumption Factor or Ratio, and has not previously been mentioned in scientific literature. The air consumption ratio is defined as a factor of dry or humid air. To be more comprehensive, a modified diagram of the composition of the flow in and out of a two-stroke fuel injection engine and the cylinder was made.

  1. Variable compression ratio device for internal combustion engine

    Science.gov (United States)

    Maloney, Ronald P.; Faletti, James J.

    2004-03-23

    An internal combustion engine, particularly suitable for use in a work machine, is provided with a combustion cylinder, a cylinder head at an end of the combustion cylinder and a primary piston reciprocally disposed within the combustion cylinder. The cylinder head includes a secondary cylinder and a secondary piston reciprocally disposed within the secondary cylinder. An actuator is coupled with the secondary piston for controlling the position of the secondary piston dependent upon the position of the primary piston. A communication port establishes fluid flow communication between the combustion cylinder and the secondary cylinder.

  2. Acoustic and Emission Characteristics of Small, High-Speed Internal Combustion Engines

    Science.gov (United States)

    1981-07-01

    The intent of this study is to obtain information on small high-speed engines so that their effect on the urban environment may be assessed, and if necessary, programs devised to reduce the noise and other emissions from vehicles using these highly d...

  3. Cylinder pressure, performance parameters, heat release, specific heats ratio and duration of combustion for spark ignition engine

    International Nuclear Information System (INIS)

    Shehata, M.S.

    2010-01-01

    An experimental work were conducted for investigating cylinder pressure, performance parameters, heat release, specific heat ratio and duration of combustion for multi cylinder spark ignition engine (SIE). Ccylinder pressure was measured for gasoline, kerosene and Liquefied Petroleum Gases (LPG) separately as a fuel for SIE. Fast Fourier Transformations (FFT) was used to cylinder pressure data transform from time domain into frequency domain to develop empirical correlation for calculating cylinder pressures at different engine speeds and different fuels. In addition, Inverse Fast Fourier Transformations (IFFT) was used to cylinder pressure reconstruct into time domain. The results gave good agreement between the measured cylinder pressure and the reconstructed cylinder pressure in time domain with different engine speeds and different fuels. The measured cylinder pressure and hydraulic dynamotor were the sours of data for calculating engine performance parameters. First law of thermodynamics and single zone heat release model with temperature dependant specific heat ratio γ(T) were the main tools for calculating heat release and heat transfer to cylinder walls. Third order empirical correlation for calculating γ(T) was one of the main gains of the present study. The correlation gave good agreement with other researchers with wide temperatures range. For kerosene, cylinder pressure is higher than for gasoline and LPG due to high volumetric efficiency where kerosene density (mass/volume ratio) is higher than gasoline and LPG. In addition, kerosene heating value is higher than gasoline that contributes in heat release rate and pressure increases. Duration of combustion for different engine speeds was determined using four different methods: (I) Mass fuel burnt, (II) Entropy change, (III) Temperature dependant specific heat ratio γ(T), and (IV) Logarithmic scale of (P and V). The duration of combustion for kerosene is smaller than for gasoline and LPG due to high

  4. Cylinder pressure, performance parameters, heat release, specific heats ratio and duration of combustion for spark ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, M.S. [Mechanical Engineering Technology Department, Higher Institute of Technology, Banha University, 4Zagalol Street, Benha, Galubia 1235 Z (Egypt)

    2010-12-15

    An experimental work were conducted for investigating cylinder pressure, performance parameters, heat release, specific heat ratio and duration of combustion for multi cylinder spark ignition engine (SIE). Ccylinder pressure was measured for gasoline, kerosene and Liquefied Petroleum Gases (LPG) separately as a fuel for SIE. Fast Fourier Transformations (FFT) was used to cylinder pressure data transform from time domain into frequency domain to develop empirical correlation for calculating cylinder pressures at different engine speeds and different fuels. In addition, Inverse Fast Fourier Transformations (IFFT) was used to cylinder pressure reconstruct into time domain. The results gave good agreement between the measured cylinder pressure and the reconstructed cylinder pressure in time domain with different engine speeds and different fuels. The measured cylinder pressure and hydraulic dynamotor were the source of data for calculating engine performance parameters. First law of thermodynamics and single zone heat release model with temperature dependant specific heat ratio {gamma}(T) were the main tools for calculating heat release and heat transfer to cylinder walls. Third order empirical correlation for calculating {gamma}(T) was one of the main gains of the present study. The correlation gave good agreement with other researchers with wide temperatures range. For kerosene, cylinder pressure is higher than for gasoline and LPG due to high volumetric efficiency where kerosene density (mass/volume ratio) is higher than gasoline and LPG. In addition, kerosene heating value is higher than gasoline that contributes in heat release rate and pressure increases. Duration of combustion for different engine speeds was determined using four different methods: (I) Mass fuel burnt, (II) Entropy change, (III) Temperature dependant specific heat ratio {gamma}(T), and (IV) Logarithmic scale of (P and V). The duration of combustion for kerosene is smaller than for gasoline and

  5. Effect of instantaneous rotational speed on the analysis of measured diesel engine cylinder pressure data

    International Nuclear Information System (INIS)

    Antonopoulos, Antonis K.; Hountalas, Dimitrios T.

    2012-01-01

    Highlights: ► The effect of in-cycle speed fluctuation on cylinder pressure measurement is investigated. ► A phasing error is introduced when sampling cylinder pressure at constant time intervals. ► The phasing error increases with the increase of engine load and decrease of engine speed. ► Measurement using constant sampling rate affects estimation of HRR, ignition angle etc. - Abstract: Diesel engine cylinder pressure measurements are widely used in field and lab applications to support among other control, monitoring and diagnostic applications. There are two methods to measure cylinder pressure, the use of a crank angle encoder, which guarantees pressure samples at fixed crank angles, and the use of constant time sampling rate. The last is frequently used due to its simplicity or because of practical restrictions. However, in order to perform thermodynamic calculations it is necessary to attribute a crank angle value to each measured pressure value. But if the in-cycle rotational speed fluctuates and this is neglected, an error will result in the values derived from the processing of the measured cylinder pressure. For this reason in the present work an experimental investigation is conducted on a single cylinder diesel test engine to identify the aforementioned problem. During the tests cylinder pressure and instantaneous speed were recorded using an accurate crank angle reference. These where then used to simulate the measurement of cylinder pressure digitized using a fixed time step. The comparison of the two cylinder pressure traces and the thermodynamic parameters derived from them, reveals the introduction of an error which depends on engine load and speed.

  6. Robust extremum seeking and speed ratio control for high-performance CVT operation

    NARCIS (Netherlands)

    Meulen, van der S.H.; Jager, de A.G.; Veldpaus, F.E.; Steinbuch, M.

    2010-01-01

    The variator in a pushbelt continuously variable transmission (CVT) enables a stepless variation of the transmission ratio within a finite range. Nowadays, the variator is electronically controlled and the variator control objectives are twofold: 1) tracking a transmission ratio reference; 2)

  7. The influence of the engine speed on the temperature distribution in the piston of the turbocharged diesel engine

    Directory of Open Access Journals (Sweden)

    Aleksander HORNIK

    2011-01-01

    Full Text Available This article presented the numeric computations of non-stationary heat flow in the form of distribution of temperature fields on characteristic surfaces of the piston for two different rotational speeds for the same engine load during 60 seconds during in which the engine worked. The object of research was a turbocharged Diesel engine with a direct fuel injection to the combustion chamber and the engine cubic capacity that is 2390 [cm3] and power rating, which is 85 [kW]. The numeric computations were carried out by the use of the finite element method (FEM with the help of COSMOS/M software and the use of the two – zone combustion model.

  8. EVALUATION METHOD OF FUEL-EFFICIENT DRIVING IN DUMP TRUCK USING VEHICLE SPEED AND ENGINE ROTATIONAL SPEED

    Science.gov (United States)

    Hirata, Masafumi; Yamamoto, Tatsuo; Yasui, Toshiaki; Hayashi, Mayu; Takebe, Atsuji; Funahashi, Masashi

    In the construction site, the light oil that the construction vehicle such as dump trucks uses accounts for 70 percent of the amount of the energy use. Therefore, the eco-driving education of the construction vehicle is effective in the fuel cost improvement and the CO2 reduction. The eco-driving education can be executed cheap and easily, and a high effect can be expected. However, it is necessary to evaluate the eco-driving situation of the construction vehicle exactly to maintain the educative effect for a long term. In this paper, the method for evaluating the effect of the fuel cost improvement was examined by using the vehicle speed and the engine rotational speed of the dump truck. In this method, "Ideal eco-driving model" that considers the difference between the vehicle model and the running condition (traffic jam etc.) is made. As a result, it is possible to evaluate the fuel consumption improvement effect of a dump truck by the same index.

  9. Economic research of the transcritical Rankine cycle systems to recover waste heat from the marine medium-speed diesel engine

    International Nuclear Information System (INIS)

    Yang, Min-Hsiung; Yeh, Rong-Hua

    2017-01-01

    The aim of this study is to investigate the economic performance of a transcritical Rankine cycle (TRC) system for recovering waste heat from the exhaust gas of a marine medium-speed diesel engine. The variation of net power output, total cost of equipments and exergy destruction are investigated for the TRC system. Furthermore, to evaluate the economic performance of energy utilization, a parameter, net power output index, which is the ratio of net power output to the total cost, is introduced of the TRC system using R125, R143a, R218 and R1234yf as working fluids. The results show that R1234yf performs the highest economic performance, followed by R143a, R125 and R218 of the TRC system. It reveals that R1234yf not only has the smallest high and low pressures of the TRC system for reducing the purchased cost of equipments, but also promotes a larger pressure ratio of the expander for generating power output among these working fluids. The comparisons of optimal pressure ratios obtained from thermodynamic and economic optimizations for these working fluids in the TRC system are also reported. In addition, an evaluation method using thermal efficiency and operating pressure ratio as parameters is proposed to assess the suitability of the working fluids of TRC system in economic analysis for waste heat recovery from the exhaust gas of a diesel engine.

  10. Effects of building aspect ratio, diurnal heating scenario, and wind speed on reactive pollutant dispersion in urban street canyons.

    Science.gov (United States)

    Tong, Nelson Y O; Leung, Dennis Y C

    2012-01-01

    A photochemistry coupled computational fluid dynamics (CFD) based numerical model has been developed to model the reactive pollutant dispersion within urban street canyons, particularly integrating the interrelationship among diurnal heating scenario (solar radiation affections in nighttime, daytime, and sun-rise/set), wind speed, building aspect ratio (building-height-to-street-width), and dispersion of reactive gases, specifically nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) such that a higher standard of air quality in metropolitan cities can be achieved. Validation has been done with both experimental and numerical results on flow and temperature fields in a street canyon with bottom heating, which justifies the accuracy of the current model. The model was applied to idealized street canyons of different aspect ratios from 0.5 to 8 with two different ambient wind speeds under different diurnal heating scenarios to estimate the influences of different aforementioned parameters on the chemical evolution of NO, NO2 and O3. Detailed analyses of vertical profiles of pollutant concentrations showed that different diurnal heating scenarios could substantially affect the reactive gases exchange between the street canyon and air aloft, followed by respective dispersion and reaction. Higher building aspect ratio and stronger ambient wind speed were revealed to be, in general, responsible for enhanced entrainment of O3 concentrations into the street canyons along windward walls under all diurnal heating scenarios. Comparatively, particular attention can be paid on the windward wall heating and nighttime uniform surface heating scenarios.

  11. Model-based diagnosis of large diesel engines based on angular speed variations of the crankshaft

    Science.gov (United States)

    Desbazeille, M.; Randall, R. B.; Guillet, F.; El Badaoui, M.; Hoisnard, C.

    2010-07-01

    This work aims at monitoring large diesel engines by analyzing the crankshaft angular speed variations. It focuses on a powerful 20-cylinder diesel engine with crankshaft natural frequencies within the operating speed range. First, the angular speed variations are modeled at the crankshaft free end. This includes modeling both the crankshaft dynamical behavior and the excitation torques. As the engine is very large, the first crankshaft torsional modes are in the low frequency range. A model with the assumption of a flexible crankshaft is required. The excitation torques depend on the in-cylinder pressure curve. The latter is modeled with a phenomenological model. Mechanical and combustion parameters of the model are optimized with the help of actual data. Then, an automated diagnosis based on an artificially intelligent system is proposed. Neural networks are used for pattern recognition of the angular speed waveforms in normal and faulty conditions. Reference patterns required in the training phase are computed with the model, calibrated using a small number of actual measurements. Promising results are obtained. An experimental fuel leakage fault is successfully diagnosed, including detection and localization of the faulty cylinder, as well as the approximation of the fault severity.

  12. Parametric analysis of diffuser requirements for high expansion ratio space engine

    Science.gov (United States)

    Wojciechowski, C. J.; Anderson, P. G.

    1981-01-01

    A supersonic diffuser ejector design computer program was developed. Using empirically modified one dimensional flow methods the diffuser ejector geometry is specified by the code. The design code results for calculations up to the end of the diffuser second throat were verified. Diffuser requirements for sea level testing of high expansion ratio space engines were defined. The feasibility of an ejector system using two commonly available turbojet engines feeding two variable area ratio ejectors was demonstrated.

  13. Particular mechanism for continuously varying the compression ratio for an internal combustion engine

    Science.gov (United States)

    Raţiu, S.; Cătălinoiu, R.; Alexa, V.; Miklos, I.; Cioată, V.

    2018-01-01

    Variable compression ratio (VCR) is a technology to adjust the compression ratio of an internal combustion engine while the engine is in operation. The paper proposes the presentation of a particular mechanism allowing the position of the top dead centre to be changed, while the position of the bottom dead centre remains fixed. The kinematics of the mechanism is studied and its trajectories are graphically represented for different positions of operation.

  14. The Application of Advanced Technique of Fan Frame Unit on High Bypass Ratio Aero Engine

    Directory of Open Access Journals (Sweden)

    Hou Peng

    2017-01-01

    Full Text Available High bypass ratio aero-engine was widely used on military and civil aviation domain, as the power of larger aircraft. Fan frame unit was the main bearing frame of high bypass ratio aero-engine, which composed of strut, HUB MID BOX and external bypass parts. Resin/composite was used on external bypass parts(acoustic liner, containment ring, fan outlet guide vane and fan case skin fillets, which not only reduced the weight and manufacturing cost, but also improved the noise absorption, containment and anti-fatigue ability of engine. The design of composite was becoming a key technique for high bypass ratio aero-engine. In special test of the core engine, nitrogen cooling system was designed to cool the cavity of spool. The nitrogen pipeline passed through the inner cavity of fan frame, then inserted into NO. 3 bearing seal, so nitrogen gas was sent into the cavity of core engine spool. On high bypass ratio aero-engine, the external bypass and fan frame inner cavity were the design platform for advanced technique, such as composite and pipeline system, and also provided guarantee for reliable operation of engine.

  15. Processing of Instantaneous Angular Speed Signal for Detection of a Diesel Engine Failure

    Directory of Open Access Journals (Sweden)

    Adam Charchalis

    2013-01-01

    Full Text Available Continuous monitoring of diesel engine performance under its operating is critical for the prediction of malfunction development and subsequently functional failure detection. Analysis of instantaneous angular speed (IAS of the crankshaft is considered as one of the nonintrusive and effective methods of the detection of combustion quality deterioration. In this paper results of experimental verification of fuel system's malfunction detecting, using optical encoder for IAS recording are presented. The implemented method relies on the comparison of measurement results, recorded under healthy and faulty conditions of the engine. Elaborated dynamic model of angular speed variations enables us to build templates of engine behavior. Recorded during experiment, values of cylinder pressure were taken for the approximation of pressure basic waveform. The main task of data processing is smoothing the raw angular speed signal. The noise is due to sensor mount vibrations, signal emitter machining, engine body vibrations, and crankshaft torsional vibrations. Smoothing of the measurement data was carried out by the implementation of the Savitzky-Golay filter. Measured signal after smoothing was compared with the model of IAS run.

  16. High speed forging of solid powder discs of large slenderness ratio

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Slenderness ratio; preform; interfacial friction law. 1. ... Interfacial friction law. Friction condition between deforming tool and work piece in metal forming are of the greatest importance concerning a number of factors such as force and mode of deformation, proper- ... The velocity field for the case under consideration is.

  17. Trends in air-breathing engines for super high speed aircraft engine system and its task

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Hiroyuki

    1988-06-10

    The second generation of space plane is under active development as the world only space plane, the Space Shuttle of U.S. will not be able to satisfy the demands in 2000 even if its flight is resumed. Conceptual study was completed in the NASP project of U.S. and the test flight of experimental plane X-30 is scheduled in mid-90's. A variety of proposals have been made by U.K, West Germany and France and the European Space Agency (ESA) is adjusting them. The mini-shuttle is under planning in Japan, which will employ H-2 rocket. Typical air-breathing engines for space planes are: Super-sonic variable cycle turbofan engine, turbo-ram jet engine, and scram jet engine, which reduces the static temperature by making the flow velocity in combustion chamber to be supersonic to fire fuels. (29 figs, 3 tabs, 9 refs)

  18. Bitumen/Water Emulsions as Fuels for High-Speed Ci Engines Preliminary Investigations

    DEFF Research Database (Denmark)

    Schramm, Jesper; Sigvardsen, R.; Forman, M.

    2003-01-01

    Mixtures of bitumen and water, are cheap fuel alternatives for combustion engines. There are, however, several problems that have to be solved before these fuels can be applied in high-speed diesel engines. These are: - emulsion break up due to high temperature or high shear stress in the injection...... system - high content of heavy metals - high emissions of particulate matter and PAH This investigation deals with the problem of separation due to high shear stress in the injection system. It is shown that the viscosity of the injected fuel can be used to estimate whether the emulsion has separated...

  19. Ratios performance indicator evaluation of selected engineering enterprises in the northeast cohesion region

    OpenAIRE

    Šenec, Alexandr

    2014-01-01

    The paper deals with the performance indicator evaluation of selected industrial companies with a predominance of engineering production. Ratio indicators were used in order to measure business performance per unit of fixed assets and per employee. Analyzed data were obtained from companies annual reports. Trends ratio indicators were intended with the help of mathematical and statistical methods. These ratios indicator assessing the level of performance, value added and operating profit p...

  20. Turbulence influence on optimum tip speed ratio for a 200 kW vertical axis wind turbine

    Science.gov (United States)

    Möllerström, E.; Eriksson, S.; Goude, A.; Ottermo, F.; Hylander, J.

    2016-09-01

    The influence of turbulence intensity (TI) on the tip speed ratio for maximum power coefficient, here called λCp_max, is studied for a 200 kW VAWT H-rotor using logged data from a 14 month period with the H-rotor operating in wind speeds up to 9 m/s. The TI - λCp_max relation is examined by dividing 10 min mean values in different turbulence intensity ranges and producing multiple CP(λ) curves. A clear positive relation between TI and λCp_max is shown and is further strengthened as possible secondary effects are examined and deemed non-essential. The established relation makes it possible to tune the control strategy to enhance the total efficiency of the turbine.

  1. The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

    Science.gov (United States)

    Reynolds, Blake; Schecter, Harry; Taylor, E S

    1939-01-01

    Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.

  2. Optimized Matching Lift Unit Transmission Ratio of Engine Driven Ducted Fan

    Directory of Open Access Journals (Sweden)

    Xiao Senlin

    2018-01-01

    Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.

  3. Air-fuel ratio control of a lean burn Si engine using fuzzy self tuning method

    International Nuclear Information System (INIS)

    Akhlaghi, M.; Bakhtiari Nejad, F.; Azadi, S.

    2000-01-01

    Reducing the exhaust emission of an spark ignition engine by means of engine modifications requires consideration of the effects of these modifications on the variations of crankshaft torque and the engine roughness respectively. Only if the roughness does not exceed a certain level the vehicle do not begin to surge. This paper presents a method for controlling the air-fuel ratio for a lean burn engine. Fuzzy rules and reasoning are utilized on-line to determine the control parameters. The main advantages of this method are simple structure and robust performance in a wide range of operating conditions. A non-linear model of an Si engine with the engine torque irregularity simulation is used in this study

  4. The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

    Science.gov (United States)

    Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan

    2012-01-01

    A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

  5. THERMAL DISPLACEMENT OF CRANKSHAFT AXIS OF SLOW-SPEED MARINE ENGINE

    Directory of Open Access Journals (Sweden)

    Lech Murawski

    2016-08-01

    Full Text Available The paper presents analysis of displacement of a crankshaft axis caused by temperature of marine, slow-speed main engine. Information of thermal displacement of a power transmission system axis is significant during a shaft line alignment and a crankshaft springing analysis. Warmed-up main engine is a source of deformations of an engine body as well as a ship hull in the area of an engine room and hence axis of a crankshaft and a shaftline. Engines' producers recommend the model of parallel displacement of the crankshaft axis under the influence of an engine heat. The model gives us the value (one number! of the crankshaft axis displacement in the hot propulsion system's condition. This model may be too simple in some cases. Presented numerical analyses are based on temperature measurements of the main engine body and the ship hull during a sea voyage. The paper presents computations of MAN B&W K98MC type engine (power: 40000 kW, revolutions: 94 rpm mounted on 4500 TEU container ship (length: 290 m. Propulsion system is working in nominal, steady-state conditions; it is the basic assumption during the analyses. Numerical analyses were preformed with usage of Nastran software based on Finite Element Method. The FEM model of the engine body comprised over 800 thousand degree of freedom. Stiffness of the ship hull (mainly double bottom with the foundation was modelled by a simple cuboid. Material properties of that cuboid were determined on the base of separately performed calculations.

  6. Efficiency versus speed in quantum heat engines: Rigorous constraint from Lieb-Robinson bound

    Science.gov (United States)

    Shiraishi, Naoto; Tajima, Hiroyasu

    2017-08-01

    A long-standing open problem whether a heat engine with finite power achieves the Carnot efficiency is investgated. We rigorously prove a general trade-off inequality on thermodynamic efficiency and time interval of a cyclic process with quantum heat engines. In a first step, employing the Lieb-Robinson bound we establish an inequality on the change in a local observable caused by an operation far from support of the local observable. This inequality provides a rigorous characterization of the following intuitive picture that most of the energy emitted from the engine to the cold bath remains near the engine when the cyclic process is finished. Using this description, we prove an upper bound on efficiency with the aid of quantum information geometry. Our result generally excludes the possibility of a process with finite speed at the Carnot efficiency in quantum heat engines. In particular, the obtained constraint covers engines evolving with non-Markovian dynamics, which almost all previous studies on this topic fail to address.

  7. A case study on optimum tip speed ratio and pitch angle laws for wind turbine rotors operating in yawed conditions

    International Nuclear Information System (INIS)

    Cuerva-Tejero, A; Lopez-Garcia, O; González-Meruelo, F; Marangoni, D

    2014-01-01

    The values of the tip speed ratio and blade pitch angle that yield maximum power coefficient are calculated for a rotor operating in yawed conditions. In a first step, the power coefficient is determined using a model based on the blade element momentum theory (BEMT) which includes a Prandtl-Glauert root-tip losses correction, a non-uniform model for the axial and tangential induction factors, and a model of the rotational augmentation effects. The BEMT model is validated with the experimental data from the NREL-UAE. The maximum values of the power coefficient are determined for different yaw angles and the corresponding values of the tip speed ratio and blade control angle are obtained. The maximum power coefficient using these optimum laws is compared to the maximum power coefficient using the optimum laws of the non-yawed case and it is shown that there is a gain in the power coefficient. For the case study presented in this paper it has been found that for yaw angles of 30° about 10% of the power coefficient can be recovered

  8. A case study on optimum tip speed ratio and pitch angle laws for wind turbine rotors operating in yawed conditions

    Science.gov (United States)

    Cuerva-Tejero, A.; Lopez-Garcia, O.; Marangoni, D.; González-Meruelo, F.

    2014-12-01

    The values of the tip speed ratio and blade pitch angle that yield maximum power coefficient are calculated for a rotor operating in yawed conditions. In a first step, the power coefficient is determined using a model based on the blade element momentum theory (BEMT) which includes a Prandtl-Glauert root-tip losses correction, a non-uniform model for the axial and tangential induction factors, and a model of the rotational augmentation effects. The BEMT model is validated with the experimental data from the NREL-UAE. The maximum values of the power coefficient are determined for different yaw angles and the corresponding values of the tip speed ratio and blade control angle are obtained. The maximum power coefficient using these optimum laws is compared to the maximum power coefficient using the optimum laws of the non-yawed case and it is shown that there is a gain in the power coefficient. For the case study presented in this paper it has been found that for yaw angles of 30° about 10% of the power coefficient can be recovered.

  9. Design and Pitch Angle Optimisation of Horizontal Axis Hydrokinetic Turbine with Constant Tip Speed Ratio

    Directory of Open Access Journals (Sweden)

    Nigam Suyash

    2017-01-01

    Full Text Available Booming population and associated energy demands, looming threat of exhaustion of conventional sources of energy and the severe environmental repercussions of the same call for alternate sources of clean energy. Hydrokinetic turbine is one such developing technology which harnesses zero-head free flow of water and affects hydrological ecology minimally. This paper discusses the optimisation of Horizontal Axis Hydrokinetic Turbine (HAHkT blade chord length and twist angle using blade element momentum (BEM theory to achieve a constant optimal angle of attack (AoA, thus maximising the power output. To achieve this while maintaining robustness at the hub end and eliminate cavitation, two different hydrofoils (S832 and E817 are selected. S832 is simulated using ANSYS 14.0 at low (00 and high (150 angles of attack and compared against more widely used NACA 4412 to study flow separation characteristics. This is followed by calculating angles of relative flow, ratios of chord length and subsequently twist angles for each blade element using MATLAB simulations. A blade model is thus developed for visualisation using computer aided designing after obtaining optimal chord lengths and pitch angles.

  10. Deriving metabolic engineering strategies from genome-scale modeling with flux ratio constraints.

    Science.gov (United States)

    Yen, Jiun Y; Nazem-Bokaee, Hadi; Freedman, Benjamin G; Athamneh, Ahmad I M; Senger, Ryan S

    2013-05-01

    Optimized production of bio-based fuels and chemicals from microbial cell factories is a central goal of systems metabolic engineering. To achieve this goal, a new computational method of using flux balance analysis with flux ratios (FBrAtio) was further developed in this research and applied to five case studies to evaluate and design metabolic engineering strategies. The approach was implemented using publicly available genome-scale metabolic flux models. Synthetic pathways were added to these models along with flux ratio constraints by FBrAtio to achieve increased (i) cellulose production from Arabidopsis thaliana; (ii) isobutanol production from Saccharomyces cerevisiae; (iii) acetone production from Synechocystis sp. PCC6803; (iv) H2 production from Escherichia coli MG1655; and (v) isopropanol, butanol, and ethanol (IBE) production from engineered Clostridium acetobutylicum. The FBrAtio approach was applied to each case to simulate a metabolic engineering strategy already implemented experimentally, and flux ratios were continually adjusted to find (i) the end-limit of increased production using the existing strategy, (ii) new potential strategies to increase production, and (iii) the impact of these metabolic engineering strategies on product yield and culture growth. The FBrAtio approach has the potential to design "fine-tuned" metabolic engineering strategies in silico that can be implemented directly with available genomic tools. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 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.

  12. Fuzzy logic speed control for the engine of an air-powered vehicle

    Directory of Open Access Journals (Sweden)

    Qihui Yu

    2016-03-01

    Full Text Available To improve the condition of air and eliminate exhaust gas pollution, this article proposes a compressed air power system. Instead of an internal combustion engine, the automobile is equipped with a compressed air engine, which transforms the energy of compressed air into mechanical motion energy. A prototype was built, and the compressed air engine was tested on an experimental platform. The output torque and energy efficiency were obtained from experimental results. When the supply pressure was set at 2 MPa and the speed was 420 r min−1, the output torque, the output power, and the energy efficiency were 56 N m, 1.93 kW, and 25%, respectively. To improve the efficiency of the system, a fuzzy logic speed control strategy is proposed and simulated. The experimental study verified that the theoretical evaluation of the system was reasonable, and this research can be referred to as the design and control of air-powered vehicles.

  13. 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.

  14. 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.

  15. Constant speed control of four-stroke micro internal combustion swing engine

    Science.gov (United States)

    Gao, Dedong; Lei, Yong; Zhu, Honghai; Ni, Jun

    2015-09-01

    The increasing demands on safety, emission and fuel consumption require more accurate control models of micro internal combustion swing engine (MICSE). The objective of this paper is to investigate the constant speed control models of four-stroke MICSE. The operation principle of the four-stroke MICSE is presented based on the description of MICSE prototype. A two-level Petri net based hybrid model is proposed to model the four-stroke MICSE engine cycle. The Petri net subsystem at the upper level controls and synchronizes the four Petri net subsystems at the lower level. The continuous sub-models, including breathing dynamics of intake manifold, thermodynamics of the chamber and dynamics of the torque generation, are investigated and integrated with the discrete model in MATLAB Simulink. Through the comparison of experimental data and simulated DC voltage output, it is demonstrated that the hybrid model is valid for the four-stroke MICSE system. A nonlinear model is obtained from the cycle average data via the regression method, and it is linearized around a given nominal equilibrium point for the controller design. The feedback controller of the spark timing and valve duration timing is designed with a sequential loop closing design approach. The simulation of the sequential loop closure control design applied to the hybrid model is implemented in MATLAB. The simulation results show that the system is able to reach its desired operating point within 0.2 s, and the designed controller shows good MICSE engine performance with a constant speed. This paper presents the constant speed control models of four-stroke MICSE and carries out the simulation tests, the models and the simulation results can be used for further study on the precision control of four-stroke MICSE.

  16. The influence of engine speed and load on the heat transfer between gases and in-cylinder walls at fired and motored conditions of an IDI diesel engine

    International Nuclear Information System (INIS)

    Sanli, Ali; Ozsezen, Ahmet N.; Kilicaslan, Ibrahim; Canakci, Mustafa

    2008-01-01

    In this study, the heat transfer characteristics between gases and in-cylinder walls at fired and motored conditions in a diesel engine were investigated by using engine data obtained experimentally. For this investigation, a four-cylinder, indirect injection (IDI) diesel engine was tested under different engine speeds and loads. The heat transfer coefficient was calculated by using Woschni expression correlated for the IDI diesel engines, and also using Annand and Hohenberg expressions. The temperature of in-cylinder gases were determined from a basic model based on the first law of thermodynamics after measuring in-cylinder pressure experimentally. The results show that the heat transfer characteristics of the IDI diesel engine strongly depend on the engine speed and load as a function of crank angle at fired and motored conditions

  17. The influence of engine speed and load on the heat transfer between gases and in-cylinder walls at fired and motored conditions of an IDI diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Sanli, Ali; Kilicaslan, Ibrahim [Department of Mechanical Education, Kocaeli University, 41380 Izmit (Turkey); Ozsezen, Ahmet N.; Canakci, Mustafa [Department of Mechanical Education, Kocaeli University, 41380 Izmit (Turkey); Alternative Fuels R and D Center, Kocaeli University, 41040 Izmit (Turkey)

    2008-08-15

    In this study, the heat transfer characteristics between gases and in-cylinder walls at fired and motored conditions in a diesel engine were investigated by using engine data obtained experimentally. For this investigation, a four-cylinder, indirect injection (IDI) diesel engine was tested under different engine speeds and loads. The heat transfer coefficient was calculated by using Woschni expression correlated for the IDI diesel engines, and also using Annand and Hohenberg expressions. The temperature of in-cylinder gases were determined from a basic model based on the first law of thermodynamics after measuring in-cylinder pressure experimentally. The results show that the heat transfer characteristics of the IDI diesel engine strongly depend on the engine speed and load as a function of crank angle at fired and motored conditions. (author)

  18. Fuel Vaporization and Its Effect on Combustion in a High-Speed Compression-Ignition Engine

    Science.gov (United States)

    Rothrock, A M; Waldron, C D

    1933-01-01

    The tests discussed in this report were conducted to determine whether or not there is appreciable vaporization of the fuel injected into a high-speed compression-ignition engine during the time available for injection and combustion. The effects of injection advance angle and fuel boiling temperature were investigated. The results show that an appreciable amount of the fuel is vaporized during injection even though the temperature and pressure conditions in the engine are not sufficient to cause ignition either during or after injection, and that when the conditions are such as to cause ignition the vaporization process affects the combustion. The results are compared with those of several other investigators in the same field.

  19. Superposition of vortex cylinders for steady and unsteady simulation of rotors of finite tip-speed ratio

    DEFF Research Database (Denmark)

    Branlard, Emmanuel Simon Pierre; Gaunaa, Mac

    2015-01-01

    coefficient obtained with this model for the constant circulation rotor is assessed and compared with that of existing solutions. Results from prescribed thrust distributions are compared with that of actuator disk simulations. Steady simulations are performed to compare with the BEM algorithm. The model......Joukowski introduced in 1912 a helical vortex model to represent the vorticity of a rotor and its wake. For an infinite number of blades but finite tip-speed ratio, the model consists of a vortex cylinder of longitudinal and tangential vorticity, a root vortex and a bound vortex disk...... is also applied to compute the velocity field in the entire domain and perform unsteady simulations. Results for an unsteady simulation corresponding to a pitch change of the rotor is used to compare the model with measurements and a BEM code with a dynamic inflow model. Copyright © 2015 John Wiley & Sons...

  20. Investigation of a new model accounting for rotors of finite tip-speed ratio in yaw or tilt

    International Nuclear Information System (INIS)

    Branlard, E; Gaunaa, M; Machefaux, E

    2014-01-01

    The main results from a recently developed vortex model are implemented into a Blade Element Momentum(BEM) code. This implementation accounts for the effect of finite tip-speed ratio, an effect which was not considered in standard BEM yaw-models. The model and its implementation are presented. Data from the MEXICO experiment are used as a basis for validation. Three tools using the same 2D airfoil coefficient data are compared: a BEM code, an Actuator-Line and a vortex code. The vortex code is further used to validate the results from the newly implemented BEM yaw-model. Significant improvements are obtained for the prediction of loads and induced velocities. Further relaxation of the main assumptions of the model are briefly presented and discussed

  1. Temperature field measurement research in high-speed diesel engine using laser induced fluorescence technology

    Science.gov (United States)

    Liu, Yongfeng; Zhang, You-tong; Gou, Chenhua; Tian, Hongsen

    2008-12-01

    Temperature laser- induced- fluorescence (LIF) 2-D imaging measurements using a new multi-spectral detection strategy are reported for high pressure flames in high-speed diesel engine. Schematic of the experimental set-up is outlined and the experimental data on the diesel engine is summarized. Experiment injection system is a third generation Bosch high-pressure common rail featuring a maximum pressure of 160 MPa. The injector is equipped with a six-hole nozzle, where each hole has a diameter of 0.124 mm. and slightly offset (by 1.0 mm) to the center of the cylinder axis to allow a better cooling of the narrow bridge between the exhaust valves. The measurement system includes a blower, which supplied the intake flow rate, and a prototype single-valve direct injection diesel engine head modified to lay down the swirled-type injector. 14-bit digital CCD cameras are employed to achieve a greater level of accuracy in comparison to the results of previous measurements. The temperature field spatial distributions in the cylinder for different crank angle degrees are carried out in a single direct-injection diesel engine.

  2. Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

    Science.gov (United States)

    Schnauffer, Kurt

    1932-01-01

    The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

  3. Supercharged two-cycle engines employing novel single element reciprocating shuttle inlet valve mechanisms and with a variable compression ratio

    Science.gov (United States)

    Wiesen, Bernard (Inventor)

    2008-01-01

    This invention relates to novel reciprocating shuttle inlet valves, effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines, employing spark or compression ignition. Also permitting the elimination of out-of-phase piston arrangements to control scavenging and supercharging of opposed-piston engines. The reciprocating shuttle inlet valve (32) and its operating mechanism (34) is constructed as a single and simple uncomplicated member, in combination with the lost-motion abutments, (46) and (48), formed in a piston skirt, obviating the need for any complex mechanisms or auxiliary drives, unaffected by heat, friction, wear or inertial forces. The reciprocating shuttle inlet valve retains the simplicity and advantages of two-cycle engines, while permitting an increase in volumetric efficiency and performance, thereby increasing the range of usefulness of two-cycle engines into many areas that are now dominated by the four-cycle engine.

  4. A neural network-based estimator for the mixture ratio of the Space Shuttle Main Engine

    Science.gov (United States)

    Guo, T. H.; Musgrave, J.

    1992-11-01

    In order to properly utilize the available fuel and oxidizer of a liquid propellant rocket engine, the mixture ratio is closed loop controlled during main stage (65 percent - 109 percent power) operation. However, because of the lack of flight-capable instrumentation for measuring mixture ratio, the value of mixture ratio in the control loop is estimated using available sensor measurements such as the combustion chamber pressure and the volumetric flow, and the temperature and pressure at the exit duct on the low pressure fuel pump. This estimation scheme has two limitations. First, the estimation formula is based on an empirical curve fitting which is accurate only within a narrow operating range. Second, the mixture ratio estimate relies on a few sensor measurements and loss of any of these measurements will make the estimate invalid. In this paper, we propose a neural network-based estimator for the mixture ratio of the Space Shuttle Main Engine. The estimator is an extension of a previously developed neural network based sensor failure detection and recovery algorithm (sensor validation). This neural network uses an auto associative structure which utilizes the redundant information of dissimilar sensors to detect inconsistent measurements. Two approaches have been identified for synthesizing mixture ratio from measurement data using a neural network. The first approach uses an auto associative neural network for sensor validation which is modified to include the mixture ratio as an additional output. The second uses a new network for the mixture ratio estimation in addition to the sensor validation network. Although mixture ratio is not directly measured in flight, it is generally available in simulation and in test bed firing data from facility measurements of fuel and oxidizer volumetric flows. The pros and cons of these two approaches will be discussed in terms of robustness to sensor failures and accuracy of the estimate during typical transients using

  5. The injection equipment of future high-speed DI diesel engines with respect to power and pollution requirements

    Energy Technology Data Exchange (ETDEWEB)

    Dolenc, A. (Monobloc Dieselmotoren GmbH, Vienna (AT))

    1990-01-01

    The development of high specific output DI diesel engines started at the low-speed end some 50 years ago primarily for marine and traction applications. Movement towards the high-speed end has been slow but steady with the majority of truck engines being very conservatively rated. There has been recent major effort on the automotive car and light commercial vehicle diesel application leading to lightweight DI diesel engines with an engine speed of 4000-5000 r/min and a rated power of 50 kW/litre displacement. These are expected to be on the market in a short period of time. The key point of this development has been the injection equipment including combustion control. In this area the use of modulated injection has the possibility of solving power and pollution requirements. (author).

  6. 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

  7. Adaptive critic learning techniques for engine torque and air-fuel ratio control.

    Science.gov (United States)

    Liu, Derong; Javaherian, Hossein; Kovalenko, Olesia; Huang, Ting

    2008-08-01

    A new approach for engine calibration and control is proposed. In this paper, we present our research results on the implementation of adaptive critic designs for self-learning control of automotive engines. A class of adaptive critic designs that can be classified as (model-free) action-dependent heuristic dynamic programming is used in this research project. The goals of the present learning control design for automotive engines include improved performance, reduced emissions, and maintained optimum performance under various operating conditions. Using the data from a test vehicle with a V8 engine, we developed a neural network model of the engine and neural network controllers based on the idea of approximate dynamic programming to achieve optimal control. We have developed and simulated self-learning neural network controllers for both engine torque (TRQ) and exhaust air-fuel ratio (AFR) control. The goal of TRQ control and AFR control is to track the commanded values. For both control problems, excellent neural network controller transient performance has been achieved.

  8. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    Science.gov (United States)

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  9. Cofactor engineering to regulate NAD+/NADH ratio with its application to phytosterols biotransformation.

    Science.gov (United States)

    Su, Liqiu; Shen, Yanbing; Zhang, Wenkai; Gao, Tian; Shang, Zhihua; Wang, Min

    2017-10-30

    Cofactor engineering is involved in the modification of enzymes related to nicotinamide adenine dinucleotides (NADH and NAD + ) metabolism, which results in a significantly altered spectrum of metabolic products. Cofactor engineering plays an important role in metabolic engineering but is rarely reported in the sterols biotransformation process owing to its use of multi-catabolic enzymes, which promote multiple consecutive reactions. Androst-4-ene-3, 17-dione (AD) and androst-1, 4-diene-3, 17-dione (ADD) are important steroid medicine intermediates that are obtained via the nucleus oxidation and the side chain degradation of phytosterols by Mycobacterium. Given that the biotransformation from phytosterols to AD (D) is supposed to be a NAD + -dependent process, this work utilized cofactor engineering in Mycobacterium neoaurum and investigated the effect on cofactor and phytosterols metabolism. Through the addition of the coenzyme precursor of nicotinic acid in the phytosterols fermentation system, the intracellular NAD + /NADH ratio and the AD (D) production of M. neoaurum TCCC 11978 (MNR M3) were higher than in the control. Moreover, the NADH: flavin oxidoreductase was identified and was supposed to exert a positive effect on cofactor regulation and phytosterols metabolism pathways via comparative proteomic profiling of MNR cultured with and without phytosterols. In addition, the NADH: flavin oxidoreductase and a water-forming NADH oxidase from Lactobacillus brevis, were successfully overexpressed and heterologously expressed in MNR M3 to improve the intracellular ratio of NAD + /NADH. After 96 h of cultivation, the expression of these two enzymes in MNR M3 resulted in the decrease in intracellular NADH level (by 51 and 67%, respectively) and the increase in NAD + /NADH ratio (by 113 and 192%, respectively). Phytosterols bioconversion revealed that the conversion ratio of engineered stains was ultimately improved by 58 and 147%, respectively. The highest AD (D

  10. Development trend of high bypass ratio turbofan engines. Ko baipasu hi tabo fan engine no kaihatsu doko

    Energy Technology Data Exchange (ETDEWEB)

    Tonomura, Y [Mitsubishi Heavy Industries Ltd., Tokyo (Japan)

    1994-03-10

    The turbofan engines for private aircrafts have come to have a high bypass ratio because a performance improvement is always requested. Because a turbofan engine is always required for a thrust reinforcement to correspond the stretch and weight increase of a fuselage after acquiring a type approval, making them a series to cover a certain thrust range becomes necessary. The concrete methods to reinforce a thrust are being achieved by an increase of fan diameter, a partial modification of high pressure compressor, a temperature rise of high pressure turbine inlet, a stage number increase of low pressure turbine, and a combination of these items just mentioned above. The PW 4000 series, CF6 series and RB211 series currently under production are being reinforced in a thrust by these methods. In this paper, as the representatives of some turbofan engines incorporating the most advanced technologies, as for 3 kinds of the large scale turbofan engine presently under development for the B777, namely GE90, PW4084, and TRENT800, their distinctive futures are summarized. 25 figs., 1 tab.

  11. Characteristics of the gait adaptation process due to split-belt treadmill walking under a wide range of right-left speed ratios in humans.

    Science.gov (United States)

    Yokoyama, Hikaru; Sato, Koji; Ogawa, Tetsuya; Yamamoto, Shin-Ichiro; Nakazawa, Kimitaka; Kawashima, Noritaka

    2018-01-01

    The adaptability of human bipedal locomotion has been studied using split-belt treadmill walking. Most of previous studies utilized experimental protocol under remarkably different split ratios (e.g. 1:2, 1:3, or 1:4). While, there is limited research with regard to adaptive process under the small speed ratios. It is important to know the nature of adaptive process under ratio smaller than 1:2, because systematic evaluation of the gait adaptation under small to moderate split ratios would enable us to examine relative contribution of two forms of adaptation (reactive feedback and predictive feedforward control) on gait adaptation. We therefore examined a gait behavior due to on split-belt treadmill adaptation under five belt speed difference conditions (from 1:1.2 to 1:2). Gait parameters related to reactive control (stance time) showed quick adjustments immediately after imposing the split-belt walking in all five speed ratios. Meanwhile, parameters related to predictive control (step length and anterior force) showed a clear pattern of adaptation and subsequent aftereffects except for the 1:1.2 adaptation. Additionally, the 1:1.2 ratio was distinguished from other ratios by cluster analysis based on the relationship between the size of adaptation and the aftereffect. Our findings indicate that the reactive feedback control was involved in all the speed ratios tested and that the extent of reaction was proportionally dependent on the speed ratio of the split-belt. On the contrary, predictive feedforward control was necessary when the ratio of the split-belt was greater. These results enable us to consider how a given split-belt training condition would affect the relative contribution of the two strategies on gait adaptation, which must be considered when developing rehabilitation interventions for stroke patients.

  12. Model Predictive Engine Air-Ratio Control Using Online Sequential Relevance Vector Machine

    Directory of Open Access Journals (Sweden)

    Hang-cheong Wong

    2012-01-01

    Full Text Available Engine power, brake-specific fuel consumption, and emissions relate closely to air ratio (i.e., lambda among all the engine variables. An accurate and adaptive model for lambda prediction is essential to effective lambda control for long term. This paper utilizes an emerging technique, relevance vector machine (RVM, to build a reliable time-dependent lambda model which can be continually updated whenever a sample is added to, or removed from, the estimated lambda model. The paper also presents a new model predictive control (MPC algorithm for air-ratio regulation based on RVM. This study shows that the accuracy, training, and updating time of the RVM model are superior to the latest modelling methods, such as diagonal recurrent neural network (DRNN and decremental least-squares support vector machine (DLSSVM. Moreover, the control algorithm has been implemented on a real car to test. Experimental results reveal that the control performance of the proposed relevance vector machine model predictive controller (RVMMPC is also superior to DRNNMPC, support vector machine-based MPC, and conventional proportional-integral (PI controller in production cars. Therefore, the proposed RVMMPC is a promising scheme to replace conventional PI controller for engine air-ratio control.

  13. High speed, self-acting shaft seal. [for use in turbine engines

    Science.gov (United States)

    Ludwig, L. P.; Hady, W. F. (Inventor)

    1975-01-01

    A high-speed, self-acting circumferential type shaft seal for use in turbine engines is disclosed. One or more conventional circumferential ring seals having a central aperture are mounted in a housing. In three of the four embodiments of the invention, a helical groove and one or more dam seals are cut in the inner cylindrical surface of the one or more ring seals. In a fourth embodiment, two or more lift pads are disposed in surface contact with the inner cylindrical surface of the seal rings. To the outside of the lift pads, two dam seals are cut in the inner cylindrical surface of two of the ring seals. In each of the embodiments, a net outward radial force was produced during rotation of the turbine causing the ring seals to lift out of contact with the turbine shaft to minimize wear of the ring seals.

  14. Human engineering analysis for the high speed civil transport flight deck

    Science.gov (United States)

    Regal, David M.; Alter, Keith W.

    1993-01-01

    The Boeing Company is investigating the feasibility of building a second generation supersonic transport. If current studies support its viability, this airplane, known as the High Speed Civil Transport (HSCT), could be launched early in the next century. The HSCT will cruise at Mach 2.4, be over 300 feet long, have an initial range of between 5000 and 6000 NM, and carry approximately 300 passengers. We are presently involved in developing an advanced flight deck for the HSCT. As part of this effort we are undertaking a human engineering analysis that involves a top-down, mission driven approach that will allow a systematic determination of flight deck functional and information requirements. The present paper describes this work.

  15. Solving Some Special Cases of Monomial Ratio Equations Appearing Frequently in Physical and Engineering Problems

    Directory of Open Access Journals (Sweden)

    Enrique Castillo

    2016-01-01

    Full Text Available We first show that monomial ratio equations are not only very common in Physics and Engineering, but the natural type of equations in many practical problems. More precisely, in the case of models involving scale variables if the used formulas are not of this type they are not physically valid. The consequence is that when estimating the model parameters we are faced with systems of monomial ratio equations that are nonlinear and difficult to solve. In this paper, we provide an original algorithm to obtain the unique solutions of systems of equations made of linear combinations of monomial ratios whose coefficient matrix has a proper null space with low dimension that permits solving the problem in a simple way. Finally, we illustrate the proposed methods by their application to two practical problems from the hydraulic and structural fields.

  16. Simultaneous high-speed spectral and infrared imaging of engine combustion

    Science.gov (United States)

    Jansons, Marcis

    2005-11-01

    A novel and unique diagnostic apparatus has been developed and applied to combustion gas mixtures in engine cylinders. The computer-controlled system integrates a modified Fastie-Ebert type spectrophotometer with four infrared CCD imagers, allowing the simultaneous acquisition of the spectrum and four spatial images, each at a discrete wavelength. Data buffering allows continuous imaging of the power stroke over consecutive engine cycles at framing rates of 1850 frames/second. Spectral resolution is 28nm with an uncertainty better than 58nm. The nominal response of the instrument is in the range 1.8--4.5mum, with a peak responsivity near the important 2.7mum bands of CO2 and H2O. The spectral range per scan is approximately 1.78mum. To interpret the measured data, a line-by-line radiation model was created utilizing the High-Resolution Transmission (HITRAN) database of molecular parameters, incorporating soot and wall emission effects. Although computationally more intensive, this model represents an improvement in accuracy over the NASA single-line-group (SLG) model which does not include the 'hot' CO2 lines of the 3.8mum region. Methane/air combustion mixture thermodynamic parameters are estimated by the iteration of model variables to yield a synthetic spectrum that, when corrected for wall effects, instrument function, responsivity, window and laboratory path transmissivity, correspond to the measured spectrum. The values of the model variables are used to interpret the corresponding spatial images. For the first time in the infrared an entire engine starting sequence has been observed over consecutive cycles. Preflame spectra measured during the compression stroke of a spark-ignition engine operating with various fuels correlate well with the synthetic spectra of the particular hydrocarbon reactants. The ability to determine concentration and spatial distribution of fuel in the engine cylinder prior to ignition has applications in stratified charge studies and

  17. Scavenging processes in high speed two-stroke engines studied with laser diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ekenberg, M.

    1998-12-31

    The major problem with the carburetted two-stroke engine is the short-circuiting of fuel that occurs during the scavenging phase. This leads to large emissions of unburned hydrocarbons. The object of this thesis has been to map the flow behaviour in the cylinder during the scavenging phase, and to detect differences between different cylinder designs. The measurement techniques used has been Laser Doppler Velocimetry (LDV), Laser Induced Fluorescence (LIF) and Laser Sheet Droplet Illumination (LSDI). Of these measurement methods, LDV and LSDI has been used inside the cylinder. LIF was used outside the exhaust port. All measurements were performed in engines running at their rated speeds, 9000 rpm for three of the designs and 5800 rpm for one design. All engines were run at full load with combustion. The LDV measurements inside the cylinder show that cylinders with cup handle transfer channels have a flow pattern inside the cylinder that gives less short-circuiting, and hence less emissions of hydrocarbons, than the cylinder with open transfer channels has. The LIF measurements outside the exhaust port show that the HC emissions that are caused by short-circuiting comes earlier in the scavenging phase for the cylinder with open transfer channels than is the case for the cylinders with cup handle transfer channels. The LSDI measurements in the cylinder give the transfer channel flow angle, for the cylinders with cup handle transfer channels. For the cylinder with open transfer channels, the results are not as useful; fuel droplet vaporization close to the exhaust port ruins the results 35 refs, 43 figs

  18. Engineering Design Study of Quasi-Axisymmetric Stellarator with Low Aspect Ratio

    International Nuclear Information System (INIS)

    Matsuoka, Keisuke; Okamura, Shoichi; Nishimura, Shin; Isobe, Mitsutaka; Suzuki, Chihiro; Shimizu, Akihiro; Tanaka, Nobuo; Hasegawa, Mitsuru; Naito, Hideji; Urata, Kazuhiro; Suzuki, Yutaka; Tsukamoto, Tadanori

    2004-01-01

    The engineering design of the quasi-axisymmetric stellarator CHS-qa is described, having a toroidal period number of 2, major radius of 1.5 m, and plasma aspect ratio of 3.2. Although the entire structure of the machine is highly nonaxisymmetric and deformative, the following major engineering concerns for the modular coils and the vacuum vessel have been resolved: (a) modular coil design (curvature and twist of conductors), (b) supporting structures for modular coils, (c) errors due to electromagnetic forces and misalignment in manufacturing processes (analysis shows that the magnetic surface is robust against such disturbances), (d) construction procedure for vacuum vessel and modular coils, and (e) ports for heating and diagnostics

  19. Efficiency and exhaust gas analysis of variable compression ratio spark ignition engine fuelled with alternative fuels

    Energy Technology Data Exchange (ETDEWEB)

    Seshaiah, N. [Mechanical Engineering Department, M.I.T.S, Madanapalle, Angallu-517325, A.P. (India)

    2010-07-01

    Considering energy crises and pollution problems today, investigations have been concentrated on decreasing fuel consumption by using alternative fuels and on lowering the concentration of toxic components in combustion products. In the present work, the variable compression ratio spark ignition engine designed to run on gasoline has been tested with pure gasoline, LPG (Isobutene), and gasoline blended with ethanol 10%, 15%, 25% and 35% by volume. Also, the gasoline mixed with kerosene at 15%, 25% and 35% by volume without any engine modifications has been tested and presented the result. Brake thermal and volumetric efficiency variation with brake load is compared and presented. CO and CO2 emissions have been also compared for all tested fuels.

  20. Comprehensive Modeling and Analysis of Rotorcraft Variable Speed Propulsion System With Coupled Engine/Transmission/Rotor Dynamics

    Science.gov (United States)

    DeSmidt, Hans A.; Smith, Edward C.; Bill, Robert C.; Wang, Kon-Well

    2013-01-01

    This project develops comprehensive modeling and simulation tools for analysis of variable rotor speed helicopter propulsion system dynamics. The Comprehensive Variable-Speed Rotorcraft Propulsion Modeling (CVSRPM) tool developed in this research is used to investigate coupled rotor/engine/fuel control/gearbox/shaft/clutch/flight control system dynamic interactions for several variable rotor speed mission scenarios. In this investigation, a prototypical two-speed Dual-Clutch Transmission (DCT) is proposed and designed to achieve 50 percent rotor speed variation. The comprehensive modeling tool developed in this study is utilized to analyze the two-speed shift response of both a conventional single rotor helicopter and a tiltrotor drive system. In the tiltrotor system, both a Parallel Shift Control (PSC) strategy and a Sequential Shift Control (SSC) strategy for constant and variable forward speed mission profiles are analyzed. Under the PSC strategy, selecting clutch shift-rate results in a design tradeoff between transient engine surge margins and clutch frictional power dissipation. In the case of SSC, clutch power dissipation is drastically reduced in exchange for the necessity to disengage one engine at a time which requires a multi-DCT drive system topology. In addition to comprehensive simulations, several sections are dedicated to detailed analysis of driveline subsystem components under variable speed operation. In particular an aeroelastic simulation of a stiff in-plane rotor using nonlinear quasi-steady blade element theory was conducted to investigate variable speed rotor dynamics. It was found that 2/rev and 4/rev flap and lag vibrations were significant during resonance crossings with 4/rev lagwise loads being directly transferred into drive-system torque disturbances. To capture the clutch engagement dynamics, a nonlinear stick-slip clutch torque model is developed. Also, a transient gas-turbine engine model based on first principles mean

  1. STEADY STATE PERFORMANCES ANALYSIS OF MODERN MARINE TWO-STROKE LOW SPEED DIESEL ENGINE USING MLP NEURAL NETWORK MODEL

    Directory of Open Access Journals (Sweden)

    Ozren Bukovac

    2016-01-01

    Full Text Available Compared to the other marine engines for ship propulsion, turbocharged two-stroke low speed diesel engines have advantages due to their high efficiency and reliability. Modern low speed ”intelligent” marine diesel engines have a flexibility in its operation due to the variable fuel injection strategy and management of the exhaust valve drive. This paper carried out verified zerodimensional numerical simulations which have been used for MLP (Multilayer Perceptron neural network predictions of marine two-stroke low speed diesel engine steady state performances. The developed MLP neural network was used for marine engine optimized operation control. The paper presents an example of achieving lowest specific fuel consumption and for minimization of the cylinder process highest temperature for reducing NOx emission. Also, the developed neural network was used to achieve optimal exhaust gases heat flow for utilization. The obtained data maps give insight into the optimal working areas of simulated marine diesel engine, depending on the selected start of the fuel injection (SOI and the time of the exhaust valve opening (EVO.

  2. CHANGE ON SPEED AIR CHARACTERISTICS THE POWER INDICATOR INDEXES OF PNEUMATIC ENGINE WITHOUT HEATING THE CHARGE DURING THE ADMITTANCE

    Directory of Open Access Journals (Sweden)

    A. Voronkov

    2014-10-01

    Full Text Available The experimental data on change according to speed characteristics of power indicator indexes of the four cylinder pneumatic engine D/S = 76/66 with a slide-valve air distributor at unchangeable temperature of compressed input air is considered.

  3. Thermodynamic analysis of a variable compression ratio diesel engine running with palm oil methyl ester

    International Nuclear Information System (INIS)

    Debnath, Biplab K.; Sahoo, Niranjan; Saha, Ujjwal K.

    2013-01-01

    Highlights: ► Energy and exergy analysis of palm oil methyl ester (POME) run diesel engine. ► Engine was run at various compression ratios (CRs) and injection timings (ITs). ► POME can recover around 26% of the energy supplied by the fuel. ► CR rise and IT change cause shaft energy per unit fuel supply to increase. ► CR of 18 and IT of 20°BTDC reduce more entropy generation. - Abstract: The present work is set to explore the effect of compression ratio (CR) and injection timing (IT) on energy and exergy potential of a palm oil methyl ester (POME) run diesel engine. Experiments are carried out in a single cylinder, direct injection, water cooled variable compression ratio diesel engine at a constant peed of 1500 rpm under a full load of 4.24 bar brake mean effective pressure (BMEP). The study involves four different CRs of 16, 17, 17.5 and 18; and three different ITs of 20°, 23° and 28°BTDC. Here, the CR of 17.5 and IT of 23°BTDC are the standard ones. The energy analysis performed for the experimental data includes shaft power, energy input through fuel, output by cooling water and exhaust, uncounted loss per unit time. Side by side, the effects of varying CR and IT on peak pressure, peak heat release rate, brake thermal efficiency and exhaust gas temperature are also studied. The exergy analysis is carried out for availability input, shaft, cooling water and exhaust availability, availability destruction and entropy generation. It shows that higher values of CR increase the shaft availability and cooling water availability, however, they decrease the exhaust flow availability. The retardation and advancement of IT give similar results. The exergy analysis also shows that with the increase of CR, the injection retardation and advancement increase the shaft availability and exergy efficiency, while it reduces the exergy destruction. The entropy generation is also reduced for the similar CR and IT modifications.

  4. Estimation of Individual Cylinder Air-Fuel Ratio in Gasoline Engine with Output Delay

    Directory of Open Access Journals (Sweden)

    Changhui Wang

    2016-01-01

    Full Text Available The estimation of the individual cylinder air-fuel ratio (AFR with a single universal exhaust gas oxygen (UEGO sensor installed in the exhaust pipe is an important issue for the cylinder-to-cylinder AFR balancing control, which can provide high-quality torque generation and reduce emissions in multicylinder engine. In this paper, the system dynamic for the gas in exhaust pipe including the gas mixing, gas transport, and sensor dynamics is described as an output delay system, and a new method using the output delay system observer is developed to estimate the individual cylinder AFR. With the AFR at confluence point augmented as a system state, an observer for the augmented discrete system with output delay is designed to estimate the AFR at confluence point. Using the gas mixing model, a method with the designed observer to estimate the individual cylinder AFR is presented. The validity of the proposed method is verified by the simulation results from a spark ignition gasoline engine from engine software enDYNA by Tesis.

  5. Flame structure of methane/oxygen shear coaxial jet with velocity ratio using high-speed imaging and OH*, CH* chemiluminescence

    Science.gov (United States)

    Shim, Myungbo; Noh, Kwanyoung; Yoon, Woongsup

    2018-06-01

    In this study, the effects of gaseous methane/oxygen injection velocity ratio on the shear coaxial jet flame structure are analyzed using high-speed imaging along with OH* and CH* chemiluminescence. The images show that, as the velocity ratio is increased, the visual flame length increases and wrinkles of the flame front are developed further downstream. The region near the equivalence ratio 1 condition in the flame could be identified by the maximum OH* position, and this region is located further downstream as the velocity ratio is increased. The dominant CH* chemiluminescence is found in the near-injector region. As the velocity ratio is decreased, the signal intensity is higher at the same downstream distance in each flame. From the results, as the velocity ratio is decreased, there is increased entrainment of the external jet, the mixing of the two jets is enhanced, the region near the stoichiometric mixture condition is located further upstream, and consequently, the flame length decreases.

  6. Effect of Diesel Engine Converted to Sequential Port Injection Compressed Natural Gas Engine on the Cylinder Pressure vs Crank Angle in Variation Engine Speeds

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    The diesel engine converted to compressed natural gas (CNG) engine effect is lower in performance. Problem statement: The hypothesis is that the lower performance of CNG engine is caused by the effect of lower in engine cylinder pressure. Are the CNG engine is lower cylinder pressure than diesel engine? This research is conducted to investigate the cylinder pressure of CNG engine as a new engine compared to diesel engine as a baseline engine. Approach: The research approach in this study is b...

  7. Influence of Compression Ratio on the Performance and Emission Characteristics of Annona Methyl Ester Operated DI Diesel Engine

    Directory of Open Access Journals (Sweden)

    Senthil Ramalingam

    2014-09-01

    Full Text Available This study aims to find the optimum performance and emission characteristics of single cylinder variable compression ratio (VCR engine with different blends of Annona methyl ester (AME as fuel. The performance parameters such as specific fuel consumption (SFC, brake thermal efficiency (BTE, and emission levels of HC, CO, Smoke, and NOx were compared with the diesel fuel. It is found that, at compression ratio of 17: 1 for A20 blended fuel (20% AME + 80% Diesel shows better performance and lower emission level which is very close to neat diesel fuel. The engine was operated with different values of compression ratio (15, 16, and 17 to find out best possible combination for operating engine with blends of AME. It is also found that the increase of compression ratio increases the BTE and reduces SFC and has lower emission without any engine in design modifications.

  8. The influence of Compression Ratio to Performance of Four Stroke Engine Use of Arak Bali as a Fuel

    Directory of Open Access Journals (Sweden)

    I Dewa Made Krishna Muku

    2012-11-01

    Full Text Available Arak bali is alternative fuel as ethanol. Ethanol has octane number 108. Octane number which was higher can over come adetonation, and can work at higher compression ratio. This experiment has done to now how the effect of compression ratiovariation to the performance four strokes engine by arak bali fuel. This research was done by changing the compressionratio that is 8,8 : 1, 8,9 : 1, 9 : 1 and 9,3 : 1. The change was done by reducing combustion chamber by scrap the cylinderhead. The result, for the used arak bali fuel to the vehicle is, if engine compression ratio to increase can be influence ofengine performance to be increase and engine fuel consumption to be decrease. For premium is, if engine compression ratioto increase to influence of engine performance to be decrease and engine fuel consumption to be increase.

  9. Modeling study on the effect of piston bowl geometries in a gasoline/biodiesel fueled RCCI engine at high speed

    International Nuclear Information System (INIS)

    Li, J.; Yang, W.M.; Zhou, D.Z.

    2016-01-01

    Highlights: • The RCCI engine fueled with gasoline and biodiesel is simulated. • The effect of piston bowl geometry is investigated. • The throat diameter of a piston can affect combustion process. • SCC shows superiority among three investigated geometries for RCCI combustion. - Abstract: This paper reports the numerical investigation on the effects of three bowl geometries on a gasoline/biodiesel fueled RCCI engine operated at high engine speed. The three bowl geometries are HCC (Hemispherical Combustion Chamber), SCC (Shallow depth Combustion Chamber) and OCC (Omega Combustion Chamber). To simulate the combustion in an RCCI engine, coupled KIVA4–CHEMKIN code was used. One recently developed reaction mechanism, which contains 107 species and 425 reactions, was adopted in this study to mimic the combustion of gasoline and biodiesel. During the simulation, the engine speed was fixed at 3600 rpm. The low reactivity fuel gasoline was premixed with air with energy percentages of 20% and 40%; accordingly, to maintain the same energy input, the percentages of biodiesel were 80% and 60% (B80 and B60). In addition, the SOI timing was varied at three levels: −11, −35 and −60 deg ATDC for B80 and B60, respectively. With SOI timing of −11 deg ATDC, the combustion is mixing-controlled; in contrast, advancing SOI timing to −60 deg ATDC, the combustion turns into the reactivity-controlled. Comparing the results on combustion characteristics, engine performance and emissions among different bowl geometries, it is concluded that the original OCC design for Toyota diesel engine is better for mixing-controlled combustion; whereas, SCC is the most suitable piston design for RCCI combustion among the three selected geometries under the investigated operating conditions of the engine. With SCC, better combustion and performance can be achieved while maintaining relatively lower CO, NO and soot emissions.

  10. Effects of butanol-diesel fuel blends on the performance and emissions of a high-speed DI diesel engine

    International Nuclear Information System (INIS)

    Rakopoulos, D.C.; Rakopoulos, C.D.; Giakoumis, E.G.; Dimaratos, A.M.; Kyritsis, D.C.

    2010-01-01

    An experimental investigation is conducted to evaluate the effects of using blends of n-butanol (normal butanol) with conventional diesel fuel, with 8%, 16% and 24% (by volume) n-butanol, on the performance and exhaust emissions of a standard, fully instrumented, four-stroke, high-speed, direct injection (DI), Ricardo/Cussons 'Hydra' diesel engine located at the authors' laboratory. The tests are conducted using each of the above fuel blends or neat diesel fuel, with the engine working at a speed of 2000 rpm and at three different loads. In each test, 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 emission parameters of the three butanol-diesel fuel blends from the baseline operation of the diesel engine, i.e., when working with neat diesel fuel, are determined and compared. It is revealed that this fuel, which can be produced from biomass (bio-butanol), forms a challenging and promising bio-fuel for diesel engines. The differing physical and chemical properties of butanol against those for the diesel fuel are used to aid the correct interpretation of the observed engine behavior.

  11. Fabrication of 4-cylinder transparent engine and measurement of the flame propagation behavior with high speed camera at idle condition

    Energy Technology Data Exchange (ETDEWEB)

    Joo, S.H. [Yonsei University Graduate School, Seoul (Korea, Republic of); Chun, K.M. [Yonse University, Seoul (Korea, Republic of)

    1998-04-01

    A transparent engine for visualization study is made using a production 4 cylinder engine. Flame propagation results from individual combustion cycles with high-speed cinematography are presented and discussed for idle condition. The flame propagation image and the in-cylinder pressure were obtained simultaneously, and the image processing software which can calculate the flame area and the flame center was developed. The flame propagation behavior of each cycle shows high cyclic variations, and there are linear correlation between flame area and the in-cylinder pressure. (author). 4 refs., 6 figs., 1 tab.

  12. Simulation research on the effect of cooled EGR, supercharging and compression ratio on downsized SI engine knock

    Science.gov (United States)

    Shu, Gequn; Pan, Jiaying; Wei, Haiqiao; Shi, Ning

    2013-03-01

    Knock in spark-ignition(SI) engines severely limits engine performance and thermal efficiency. The researches on knock of downsized SI engine have mainly focused on structural design, performance optimization and advanced combustion modes, however there is little for simulation study on the effect of cooled exhaust gas recirculation(EGR) combined with downsizing technologies on SI engine performance. On the basis of mean pressure and oscillating pressure during combustion process, the effect of different levels of cooled EGR ratio, supercharging and compression ratio on engine dynamic and knock characteristic is researched with three-dimensional KIVA-3V program coupled with pressure wave equation. The cylinder pressure, combustion temperature, ignition delay timing, combustion duration, maximum mean pressure, and maximum oscillating pressure at different initial conditions are discussed and analyzed to investigate potential approaches to inhibiting engine knock while improving power output. The calculation results of the effect of just cooled EGR on knock characteristic show that appropriate levels of cooled EGR ratio can effectively suppress cylinder high-frequency pressure oscillations without obvious decrease in mean pressure. Analysis of the synergistic effect of cooled EGR, supercharging and compression ratio on knock characteristic indicates that under the condition of high supercharging and compression ratio, several times more cooled EGR ratio than that under the original condition is necessarily utilized to suppress knock occurrence effectively. The proposed method of synergistic effect of cooled EGR and downsizing technologies on knock characteristic, analyzed from the aspects of mean pressure and oscillating pressure, is an effective way to study downsized SI engine knock and provides knock inhibition approaches in practical engineering.

  13. Potential for using a tyre pyrolysis oil-biodiesel blend in a diesel engine at different compression ratios

    International Nuclear Information System (INIS)

    Sharma, Abhishek; Murugan, S.

    2015-01-01

    Highlights: • The possibility of operating a compression ignition engine with a non petroleum diesel fuel. • A possible solution to replace certain amount of biodiesel by tyre pyrolysis oil in a biodiesel fueled diesel engine. • The optimum compression ratio for engine fueled with biodiesel-tyre pyrolysis oil blend. - Abstract: This study is aimed at investigating effects of varying the compression ratio at optimum injection timing and nozzle opening pressure on the behaviour of a diesel engine, using a non-petroleum fuel, i.e. a blend of 80% biodiesel, and 20% oil obtained from pyrolysis of waste tyres. The engine was subjected to one lower (16.5) and one higher (18.5) compression ratio in addition to the standard compression ratio of 17.5. At the higher compression ratio of 18.5 and full load, shorter ignition delay, maximum cylinder pressure and higher heat release rate were found for the blend, compared to those of the original compression ratio. The increase in the compression ratio from 17.5 to 18.5 for the blend improved the brake thermal efficiency by about 8% compared to that of the original compression ratio at full load. The experimental results indicated that for the blend at a higher compression ratio of 18.5, the brake specific carbon monoxide (BSCO), brake specific hydrocarbon emission (BSHC) and smoke opacity were reduced by about 10.5%, 32%, and 17.4% respectively, than those of the original compression ratio at full load

  14. Influence of engine speed and the course of the fuel injection characteristics on forming the average combustion temperature in the cylinder of turbo diesel engine

    Directory of Open Access Journals (Sweden)

    Piotr GUSTOF

    2007-01-01

    Full Text Available Average combustion temperatures inside a turbo diesel engine for the same load and the same total doze of fuel for two rotational speeds: 2004 [rpm] and 4250 [rpm] are presented in this paper. The aim of this work is also the evaluation of the influence of the temporary course of the fuel injection characteristics on forming temperature in theengine cylinder space for these temperatures. The calculations were carried out by means of two zone combustion model.

  15. Numerical analysis of knock during HCCI in a high compression ratio methanol engine based on LES with detailed chemical kinetics

    International Nuclear Information System (INIS)

    Zhen, Xudong; Wang, Yang

    2015-01-01

    Highlights: • Knock during HCCI in a high compression ratio methanol engine was modeled. • A detailed methanol mechanism was used to simulate the knocking combustion. • Compared with the SI engines, the HCCI knocking combustion burnt faster. • The reaction rate of HCO had two obvious peaks, one was positive, and another was negative. • Compared with the SI engines, the values of the reaction rates of CH 2 O, H 2 O 2 , and HO 2 were higher, and it had negative peaks. - Abstract: In this study, knock during HCCI (homogeneous charge compression ignition) was studied based on LES (large eddy simulation) with methanol chemical kinetics (84-reaction, 21-species) in a high compression ratio methanol engine. The non-knocking and knocking combustion of SI (spark ignition) and HCCI engines were compared. The results showed that the auto-ignition spots were initially occurred near the combustion chamber wall. The knocking combustion burnt faster during HCCI than SI methanol engine. The HCO reaction rate was different from SI engine, it had two obvious peaks, one was positive peak, and another was negative peak. Compared with the SI methanol engine, in addition to the concentration of HCO, the concentrations of the other intermediate products and species such as CO, OH, CH 2 O, H 2 O 2 , HO 2 were increased significantly; the reaction rates of CH 2 O, H 2 O 2 , and HO 2 had negative peaks, and whose values were several times higher than SI methanol engine

  16. Advantages of variable-speed operation of hydraulic turbo-engines; Vorteile durch den drehzahlvariablen Betrieb von hydraulischen Stroemungsmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Harbort, T. [Stuttgart Univ. (Germany). Inst. fuer Stroemungsmechanik und Hydraulische Stroemungsmaschinen

    1997-12-31

    The performance of current hydraulic turbo-engines in the variable speed sector is monitored and judged. The study covers radial and axial engines as well as Pelton turbines. Variable-speed operation of hydraulic turbo-engines can be realized by means of different combinations of electrical rotating machines and frequency converters. The operating range of the frequency converter plays an important role in the optimization of performance and is taken into account. The smoothness of run of reaction turbines and their cavitation performance can be enhanced by speed regulation. But above all, efficiency is more or less substantially enhanced during partial load or in the case of greatly varying heights of drop. The latter holds true also of Pelton turbines. (orig.) [Deutsch] Das Betriebsverhalten der gaengigen hydraulischen Stroemungsmaschinen wird in Hinblick auf den drehzahlvariablen Betrieb erfasst und beurteilt. Die Untersuchung erfolgt fuer Radialmaschinen, Axialmaschinen und Peltonturbinen. Der drehzahlvariable Betrieb hydraulischer Stroemungsmaschinen kann mit verschiedenen Kombinationen von elektrischen Maschinen und Frequenzumrichtern realisiert werden. Der Arbeitsbereich des Frequenzumrichters spielt eine wichtige Rolle fuer die Optimierung des Betriebsverhaltens und wird beruecksichtigt. Bei Ueberdruckturbinen kann man durch Drehzahlregelung eine groessere Laufruhe sowie ein guenstigeres Kavitationsverhalten erreichen. Vor allem aber sind im Teillastbereich oder bei stark schwankenden Fallhoehen mehr oder weniger grosse Wirkungsgradgewinne erzielbar. Das letztere gilt auch fuer Peltonturbinen. (orig.)

  17. Sensitivity Analysis of Heavy Fuel Oil Spray and Combustion under Low-Speed Marine Engine-Like Conditions

    Directory of Open Access Journals (Sweden)

    Lei Zhou

    2017-08-01

    Full Text Available On account of their high power, thermal efficiency, good reliability, safety, and durability, low-speed two-stroke marine diesel engines are used as the main drive devices for large fuel and cargo ships. Most marine engines use heavy fuel oil (HFO as the primary fuel, however, the physical and chemical characteristics of HFO are not clear because of its complex thermophysical properties. The present study was conducted to investigate the effects of fuel properties on the spray and combustion characteristics under two-stroke marine engine-like conditions via a sensitivity analysis. The sensitivity analysis of fuel properties for non-reacting and reacting simulations are conducted by comparing two fuels having different physical properties, such as fuel density, dynamic viscosity, critical temperature, and surface tension. The performances of the fuels are comprehensively studied under different ambient pressures, ambient temperatures, fuel temperatures, and swirl flow conditions. From the results of non-reacting simulations of HFO and diesel fuel properties in a constant volume combustion chamber, it can be found that the increase of the ambient pressure promotes fuel evaporation, resulting in a reduction in the steady liquid penetration of both diesel and HFO; however, the difference in the vapor penetrations of HFO and diesel reduces. Increasing the swirl flow significantly influences the atomization of both HFO and diesel, especially the liquid distribution of diesel. It is also found that the ambient temperature and fuel temperature have the negative effects on Sauter mean diameter (SMD distribution. For low-speed marine engines, the combustion performance of HFO is not sensitive to activation energy in a certain range of activation energy. At higher engine speed, the difference in the effects of different activation energies on the in-cylinder pressure increases. The swirl flow in the cylinder can significantly promote fuel evaporation and

  18. Role of Air-Breathing Pulse Detonation Engines in High Speed Propulsion

    Science.gov (United States)

    Povinelli, Louis A.; Lee, Jin-Ho; Anderberg, Michael O.

    2001-01-01

    In this paper, the effect of flight Mach number on the relative performance of pulse detonation engines and gas turbine engines is investigated. The effect of ram and mechanical compression on combustion inlet temperature and the subsequent sensible heat release is determined. Comparison of specific thrust, fuel consumption and impulse for the two engines show the relative benefits over the Mach number range.

  19. Response surface methodology based optimization of diesel–n-butanol –cotton oil ternary blend ratios to improve engine performance and exhaust emission characteristics

    International Nuclear Information System (INIS)

    Atmanlı, Alpaslan; Yüksel, Bedri; İleri, Erol; Deniz Karaoglan, A.

    2015-01-01

    Highlights: • RSM based optimization for optimum blend ratio of diesel fuel, n-butanol and cotton oil was done. • 65.5 vol.% diesel fuel, 23.1 vol.% n-butanol and 11.4 vol.% cotton oil (DnBC) was determined. • DnBC decreased brake torque, brake power, BTE and BMEP, while increased BSFC. • DnBC decreased NO x , CO and HC emissions. - Abstract: Many studies declare that 20% biodiesel is the optimum concentration for biodiesel–diesel fuel blends to improve performance. The present work focuses on finding diesel fuel, n-butanol, and cotton oil optimum blend ratios for diesel engine applications by using the response surface method (RSM). Experimental test fuels were prepared by choosing 7 different concentrations, where phase decomposition did not occur in the phase diagram of −10 °C. Experiments were carried out at full load conditions and the constant speed (2200 rpm) of maximum brake torque to determine engine performance and emission parameters. According to the test results of the engine, optimization was done by using RSM considering engine performance and exhaust emissions parameters, to identify the rates of concentrations of components in the optimum blend of three. Confirmation tests were employed to compare the output values of concentrations that were identified by optimization. The real experiment results and the R 2 actual values that show the relation between the outputs from the optimizations and real experiments were determined in high accordance. The optimum component concentration was determined as 65.5 vol.% diesel, 23.1 vol.% n-butanol and 11.4 vol.% cotton oil (DnBC). According to engine performance tests brake torque, brake power, BTE and BMEP of DnBC decreased while BSFC increased compared to those of diesel fuel. NO x , CO and HC emissions of DnBC drastically decreased as 11.33%, 45.17% and 81.45%, respectively

  20. Effects of unbalance location on dynamic characteristics of high-speed gasoline engine turbocharger with floating ring bearings

    Science.gov (United States)

    Wang, Longkai; Bin, Guangfu; Li, Xuejun; Liu, Dingqu

    2016-03-01

    For the high-speed gasoline engine turbocharger rotor, due to the heterogeneity of multiple parts material, manufacturing and assembly errors, running wear in impeller and uneven carbon of turbine, the random unbalance usually can be developed which will induce excessive rotor vibration, and even lead to nonlinear vibration accidents. However, the investigation of unbalance location on the nonlinear high-speed turbocharger rotordynamic characteristics is less. In order to discuss the rotor unbalance location effects of turbocharger with nonlinear floating ring bearings(FRBs), the realistic turbocharger of gasoline engine is taken as a research object. The rotordynamic equations of motion under the condition of unbalance are derived by applied unbalance force and nonlinear oil film force of FRBs. The FE model of turbocharger rotor-bearing system is modeled which includes the unbalance excitation and nonlinear FRBs. Under the conditions of four different applied locations of unbalance, the nonlinear transient analyses are performed based on the rotor FEM. The differences of dynamic behavior are obvious to the turbocharger rotor systems for four conditions, and the bifurcation phenomena are different. From the results of waterfall and transient response analysis, the speed for the appearance of fractional frequency is not identical and the amplitude magnitude is different from the different unbalance locations, and the non-synchronous vibration does not occur in the turbocharger and the amplitude is relative stable and minimum under the condition 4. The turbocharger vibration and non-synchronous components could be reduced or suppressed by controlling the applied location of unbalance, which is helpful for the dynamic design, fault diagnosis and vibration control of the high-speed gasoline engine turbochargers.

  1. STUDY OF ALTERNATIVE FUELS AND EFFECTS OF COMPRESSION RATIO ON THERMAL EFFICIENCY AND ENGINE POWER

    Directory of Open Access Journals (Sweden)

    Sarjito Sarjito

    2017-01-01

    Full Text Available This paper was a case study during the sabatical program at Kingston University London in February 2007. It has been studied by team of motorsport automotive department Kingston University London and it has been elaborated as a final project on Master Program. This study takes into account some of the issues surrounding the debate about alcohol fuels in Motorsport and the wider automotive sector and is primarily concerned to add data where there seems to be little existing research since Motorsport is a secretive business. Motorsport plays an important part in the automotive industry and is a sport enjoyed worldwide. Racing practice is regarded as using the best available resources and technology as it requires optimal performance. The racing arena gives engineers the opportunity to test valuable technological solutions to prove their merits. Therefore, racing is the natural starting point for introducing new technological solutions to the public and could lead to the wholesale conversion to renewable fuels to meet our automotive energy needs. Alcohol has unique properties that make superior in many ways to ordinary gasoline. The higher knock resistance allows for higher compression ratios to be utilized resulting in higher power outputs and thermal efficiency. The efficient use of energy is of growing concern in all spheres of life and the automotive sector needs to be front runner in these efforts.

  2. Design, Fabrication, and Performance Test of a 100-W Helical-Blade Vertical-Axis Wind Turbine at Low Tip-Speed Ratio

    Directory of Open Access Journals (Sweden)

    Dowon Han

    2018-06-01

    Full Text Available A 100-W helical-blade vertical-axis wind turbine was designed, manufactured, and tested in a wind tunnel. A relatively low tip-speed ratio of 1.1 was targeted for usage in an urban environment at a rated wind speed of 9 m/s and a rotational speed of 170 rpm. The basic dimensions were determined through a momentum-based design method according to the IEC 61400-2 protocol. The power output was estimated by a mathematical model that takes into account the aerodynamic performance of the NACA0018 blade shape. The lift and drag of the blade with respect to the angle of attack during rotation were calculated using 2D computational fluid dynamics (CFD simulation to take into account stall region. The average power output calculated by the model was 108.34 W, which satisfies the target output of 100 W. The manufactured wind turbine was tested in a large closed-circuit wind tunnel, and the power outputs were measured for given wind speeds. At the design condition, the measured power output was 114.7 W, which is 5.9% higher than that of the mathematical model. This result validates the proposed design method and power estimation by the mathematical model.

  3. A New Family of Nonlinear Observers for SI Engine Air/Fuel Ratio Control

    DEFF Research Database (Denmark)

    Jensen, P. B.; Olsen, M. B.; Poulsen, J.

    1997-01-01

    The paper treats a newly developed set of nonlinear observers for advanced spark ignition engine control.......The paper treats a newly developed set of nonlinear observers for advanced spark ignition engine control....

  4. Fuzzy logic speed control for the engine of an air-powered vehicle

    OpenAIRE

    Qihui Yu; Yan Shi; Maolin Cai; Weiqing Xu

    2016-01-01

    To improve the condition of air and eliminate exhaust gas pollution, this article proposes a compressed air power system. Instead of an internal combustion engine, the automobile is equipped with a compressed air engine, which transforms the energy of compressed air into mechanical motion energy. A prototype was built, and the compressed air engine was tested on an experimental platform. The output torque and energy efficiency were obtained from experimental results. When the supply pressure ...

  5. Combustion and emissions characteristics of high n-butanol/diesel ratio blend in a heavy-duty diesel engine and EGR impact

    International Nuclear Information System (INIS)

    Chen, Zheng; Wu, Zhenkuo; Liu, Jingping; Lee, Chiafon

    2014-01-01

    Highlights: • Effects of EGR on high n-butanol/diesel ratio blend (Bu40) were investigated and compared with neat diesel (Bu00). • Bu40 has higher NOx due to wider combustion high-temperature region. • Bu40 has lower soot due to local lower equivalence ratio distribution. • Bu40 has higher CO due to lower gas temperature in the late expansion process. • For Bu40, EGR reduces NOx emissions dramatically with no obvious influence on soot. - Abstract: In this work, the combustion and emission fundamentals of high n-butanol/diesel ratio blend with 40% butanol (i.e., Bu40) in a heavy-duty diesel engine were investigated by experiment and simulation at constant engine speed of 1400 rpm and an IMEP of 1.0 MPa. Additionally, the impact of EGR was evaluated experimentally and compared with neat diesel fuel (i.e., Bu00). The results show that Bu40 has higher cylinder pressure, longer ignition delay, and faster burning rate than Bu00. Compared with Bu00, moreover, Bu40 has higher NOx due to wider combustion high-temperature region, lower soot due to local lower equivalence ratio distribution, and higher CO due to lower gas temperature in the late expansion process. For Bu40, EGR reduces NOx emissions dramatically with no obvious influence on soot. Meanwhile, there is no significant change in HC and CO emissions and indicated thermal efficiency (ITE) with EGR until EGR threshold is reached. When EGR rate exceeds the threshold level, HC and CO emissions increase dramatically, and ITE decreases markedly. Compared with Bu00, the threshold of Bu40 appears at lower EGR rate. Consequently, combining high butanol/diesel ratio blend with medium EGR has the potential to achieve ultra-low NOx and soot emissions simultaneously while maintaining high thermal efficiency level

  6. Investigation at Low Speeds of the Effect of Aspect Ratio and Sweep on Rolling Stability Derivatives of Untapered Wings

    Science.gov (United States)

    Goodman, Alex; Fisher, Lewis R

    1950-01-01

    A low-scale wind-tunnel investigation was conducted in rolling flow to determine the effects of aspect ratio and sweep (when varied independently) on the rolling stability derivatives for a series of untapered wings. The rolling-flow equipment of the Langley stability tunnel was used for the tests. The data of the investigation have been used to develop a method of accounting for the effects of the drag on the yawing moment due to rolling throughout the lift range.

  7. Studying the effect of compression ratio on an engine fueled with waste oil produced biodiesel/diesel fuel

    Directory of Open Access Journals (Sweden)

    Mohammed EL_Kassaby

    2013-03-01

    Full Text Available Wasted cooking oil from restaurants was used to produce neat (pure biodiesel through transesterification, and then used to prepare biodiesel/diesel blends. The effect of blending ratio and compression ratio on a diesel engine performance has been investigated. Emission and combustion characteristics was studded when the engine operated using the different blends (B10, B20, B30, and B50 and normal diesel fuel (B0 as well as when varying the compression ratio from 14 to 16 to 18. The result shows that the engine torque for all blends increases as the compression ratio increases. The bsfc for all blends decreases as the compression ratio increases and at all compression ratios bsfc remains higher for the higher blends as the biodiesel percent increase. The change of compression ratio from 14 to 18 resulted in, 18.39%, 27.48%, 18.5%, and 19.82% increase in brake thermal efficiency in case of B10, B20, B30, and B50 respectively. On an average, the CO2 emission increased by 14.28%, the HC emission reduced by 52%, CO emission reduced by 37.5% and NOx emission increased by 36.84% when compression ratio was increased from 14 to 18. In spite of the slightly higher viscosity and lower volatility of biodiesel, the ignition delay seems to be lower for biodiesel than for diesel. On average, the delay period decreased by 13.95% when compression ratio was increased from 14 to 18. From this study, increasing the compression ratio had more benefits with biodiesel than that with pure diesel.

  8. Investigations of effects of pilot injection with change in level of compression ratio in a common rail diesel engine

    Directory of Open Access Journals (Sweden)

    Gajarlawar Nilesh

    2013-01-01

    Full Text Available These day diesel engines are gaining lots of attention as prime movers for various source of transportation. It offers better drive ability, very good low end torque and importantly the lower CO2 emission. Diesel engines are bridging the gap between gasoline and diesel engines. Better noise vibration and harshness levels of gasoline engine are realized to great extent in diesel engine, thanks to common rail direct injection system. Common rail injection system is now well known entity. Its unique advantage is flexible in operation. In common rail injection system, number of injection prior and after main injection at different injection pressure is possible. Due to multiple injections, gain in emission reduction as well as noise has been already experienced and demonstrated by researcher in the past. However, stringent emission norms for diesel engine equipped vehicle demands for further lower emission of oxides of nitrogen (NOx and particulate matter (PM. In the present paper, authors attempted to study the effect of multiple injections in combination with two level of compression ratio. The aim was to study the combustion behavior with the reduced compression ratio which is going to be tried out as low temperature combustion concept in near future. The results were compared with the current level of compression ratio. Experiments were carried out in 2.2L cubic capacity engine with two levels of compression ratios. Pilot injection separation and quantities were varied keeping the main injection, rail pressure, boost pressure and EGR rate constant. Cylinder pressure traces and gross heat release rates were measured and analyzed to understand the combustion behavior.

  9. Exploring the stochastic and deterministic aspects of cyclic emission variability on a high speed spark-ignition engine

    International Nuclear Information System (INIS)

    Karvountzis-Kontakiotis, A.; Dimaratos, A.; Ntziachristos, L.; Samaras, Z.

    2017-01-01

    This study contributes to the understanding of cycle-to-cycle emissions variability (CEV) in premixed spark-ignition combustion engines. A number of experimental investigations of cycle-to-cycle combustion variability (CCV) exist in published literature; however only a handful of studies deal with CEV. This study experimentally investigates the impact of CCV on CEV of NO and CO, utilizing experimental results from a high-speed spark-ignition engine. Both CEV and CCV are shown to comprise a deterministic and a stochastic component. Results show that at maximum break torque (MBT) operation, the indicated mean effective pressure (IMEP) maximizes and its coefficient of variation (COV_I_M_E_P) minimizes, leading to minimum variation of NO. NO variability and hence mean NO levels can be reduced by more than 50% and 30%, respectively, at advanced ignition timing, by controlling the deterministic CCV using cycle resolved combustion control. The deterministic component of CEV increases at lean combustion (lambda = 1.12) and this overall increases NO variability. CEV was also found to decrease with engine load. At steady speed, increasing throttle position from 20% to 80%, decreased COV_I_M_E_P, COV_N_O and COV_C_O by 59%, 46%, and 6% respectively. Highly resolved engine control, by means of cycle-to-cycle combustion control, appears as key to limit the deterministic feature of cyclic variability and by that to overall reduce emission levels. - Highlights: • Engine emissions variability comprise both stochastic and deterministic components. • Lean and diluted combustion conditions increase emissions variability. • Advanced ignition timing enhances the deterministic component of variability. • Load increase decreases the deterministic component of variability. • The deterministic component can be reduced by highly resolved combustion control.

  10. High speed video recording system on a chip for detonation jet engine testing

    Directory of Open Access Journals (Sweden)

    Samsonov Alexander N.

    2018-01-01

    Full Text Available This article describes system on a chip development for high speed video recording purposes. Current research was started due to difficulties in selection of FPGAs and CPUs which include wide bandwidth, high speed and high number of multipliers for real time signal analysis implementation. Current trend of high density silicon device integration will result soon in a hybrid sensor-controller-memory circuit packed in a single chip. This research was the first step in a series of experiments in manufacturing of hybrid devices. The current task is high level syntheses of high speed logic and CPU core in an FPGA. The work resulted in FPGA-based prototype implementation and examination.

  11. Design and operation of a medium speed 12-cylinder coal-fueled diesel engine. Phase 2: Improvements

    Science.gov (United States)

    Confer, G. L.; Hsu, B. D.; McDowell, R. E.; Gal, E.; Vankleunen, W.; Kaldor, S.; Mengel, M.

    Under the sponsorship of the US Department of Energy, General Electric has been pioneering the development of a coal fired diesel engine to power a locomotive. The feasibility of using a coal water slurry (CWS) mixture as a fuel in a medium speed diesel engine has been demonstrated with the first successful locomotive systems test in 1991 on the GE Transportation Systems test track in Erie, PA. Phase 2 of the development process incorporates the results of the programs research in durable engine parts, improved combustion efficiency, and emissions reduction. A GE 7FDL12 engine has been built using diamond insert injector nozzles, tungsten carbide coated piston rings, and tungsten carbide coated liners to overcome power assembly wear. Electronic controlled fuel injection for both diesel pilot and main CWS injector were incorporated to control injection timing. An envelop filter and copper oxide sorbent system were used to cleanup engine emissions. The system is capable of removing over 99% of the particulates, 90% of the SO2, and 85% of NO(x).

  12. Investigating SO3 Formation from the Combustion of Heavy Fuel Oil in a Four-Stroke Medium Speed Test Engine

    DEFF Research Database (Denmark)

    Cordtz, Rasmus Lage; Schramm, Jesper; Rabe, Rom

    2013-01-01

    conversion and indirect detection via light absorption in a photometer. Present results show that SO3 formation is favored by elevated pressure histories, premixed combustion, and reduced speeds. The fraction of fuel sulfur converted to SO3 is measured to be on the order of 0.5%−2.4%, corresponding to 4......The validation of detailed models, in terms of SO3 formation in large marine engines operating on sulfur-containing heavy fuel oils (HFOs), relies on experimental work. The requisite is addressed in the present work, where SO3 is measured in the exhaust gas of an 80 kW medium-speed single......−14 ppmv. SO3 and NOx are not comparable, according to thermodynamic considerations, yet both species involve the radical pool and are studied in parallel. Resulting emissions of SO3 and NOx in the exhaust gas follow a comparable trend throughout the experiments....

  13. Engine technology challenges for a 21st century high speed civil transport

    Science.gov (United States)

    Shaw, Robert J.

    1991-01-01

    Recent NASA funded studies by Boeing and Douglas suggest an opportunity exists for a 21st Century High Speed Civil Transport (HSCT) to become part of the international air transportation system. However, before this opportunity for high speed travel can be realized, certain environmental and and economic barrier issues must be overcome. These challenges are outlined. Research activities which NASA has planned to address these barrier issues and to provide a technology base to allow U.S. manufacturers to make an informed go/no go decision on developing the HSCT are discussed.

  14. An engineer's guide to automated testing of high-speed interfaces

    CERN Document Server

    Moreira, Jose

    2010-01-01

    Providing a complete introduction to the state-of-the-art in high-speed digital testing with automated test equipment (ATE), this practical resource is the first book focus exclusively on this increasingly important topic. Featuring clear examples, this one-stop reference covers all critical aspects of the subject, from high-speed digital basics, ATE instrumentation for digital applications, and test and measurements, to production testing, support instrumentation and text fixture design. This in-depth volume also discusses at advanced ATE topics, such as multiplexing of ATE pin channels and t

  15. Demonstrating the Performance and Emission Characteristics of a Variable Compression Ratio, Alvar-Cycle Engine

    OpenAIRE

    Erlandsson, Olof; Lundholm, Gunnar; Söderberg, Fredrik; Johansson, Bengt; Wong, Victor W.

    1998-01-01

    This paper is a direct continuation of a previous study that addressed the performance and design of a variable compression engine, the Alvar-Cycle Engine [1]. The earlier study was presented at the SAE International Conference and Exposition in Detroit during February 23- 26, 1998 as SAE paper 981027. In the present paper test results from a single cylinder prototype are reviewed and compared with a similar conventional engine. Efficiency and emissions are shown as fu...

  16. Estimation of Engine Intake Air Mass Flow using a generic Speed-Density method

    OpenAIRE

    Vojtíšek Michal; Kotek Martin

    2014-01-01

    Measurement of real driving emissions (RDE) from internal combustion engines under real-world operation using portable, onboard monitoring systems (PEMS) is becoming an increasingly important tool aiding the assessment of the effects of new fuels and technologies on environment and human health. The knowledge of exhaust flow is one of the prerequisites for successful RDE measurement with PEMS. One of the simplest approaches for estimating the exhaust flow from virtually any engine is its comp...

  17. Adaptation of a zero-dimensional cylinder pressure model for diesel engines using the crankshaft rotational speed

    Science.gov (United States)

    Weißenborn, E.; Bossmeyer, T.; Bertram, T.

    2011-08-01

    Tighter emission regulations are driving the development of advanced engine control strategies relying on feedback information from the combustion chamber. In this context, it is especially seeked for alternatives to expensive in-cylinder pressure sensors. The present study addresses these issues by pursuing a simulation-based approach. It focuses on the extension of an empirical, zero-dimensional cylinder pressure model using the engine speed signal in order to detect cylinder-wise variations in combustion. As a special feature, only information available from the standard sensor configuration are utilized. Within the study, different methods for the model-based reconstruction of the combustion pressure including nonlinear Kalman filtering are compared. As a result, the accuracy of the cylinder pressure model can be enhanced. At the same time, the inevitable limitations of the proposed methods are outlined.

  18. Characteristics of pressure wave in common rail fuel injection system of high-speed direct injection diesel engines

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Herfatmanesh

    2016-05-01

    Full Text Available The latest generation of high-pressure common rail equipment now provides diesel engines possibility to apply as many as eight separate injection pulses within the engine cycle for reducing emissions and for smoothing combustion. With these complicated injection arrangements, optimizations of operating parameters for various driving conditions are considerably difficult, particularly when integrating fuel injection parameters with other operating parameters such as exhaust gas recirculation rate and boost pressure together for evaluating calibration results. Understanding the detailed effects of fuel injection parameters upon combustion characteristics and emission formation is therefore particularly critical. In this article, the results and discussion of experimental investigations on a high-speed direct injection light-duty diesel engine test bed are presented for evaluating and analyzing the effects of main adjustable parameters of the fuel injection system on all regulated emission gases and torque performance. Main injection timing, rail pressure, pilot amount, and particularly pilot timing have been examined. The results show that optimization of each of those adjustable parameters is beneficial for emission reduction and torque improvement under different operating conditions. By exploring the variation in the interval between the pilot injection and the main injection, it is found that the pressure wave in the common rail has a significant influence on the subsequent injection. This suggests that special attentions must be paid for adjusting pilot timing or any injection interval when multi-injection is used. With analyzing the fuel amount oscillation of the subsequent injections to pilot separation, it demonstrates that the frequency of regular oscillations of the actual fuel amount or the injection pulse width with the variation in pilot separation is always the same for a specified fuel injection system, regardless of engine speed

  19. New technology and neo-science on the nuclear fusion reactor engineering. ITER and super high speed phenomena

    International Nuclear Information System (INIS)

    1996-12-01

    This research meeting has been held under cooperation of the ''nuclear fusion reactor engineering research group'' and ''nuclear fusion reactor materials research group'' of the Yayoi Research Group. This meeting was planned and conducted for 2 days under the following predominant thema: Present status of research on thermo-nuclear fusion experimental reactor engineering design (ITER/EDA) and its promoting method in Japan, and a new scientific side in the research and development of nuclear fusion reactor materials or the super high speed phenomena. In the former item, the following reports were published: Creative period of R and D on the nuclear fusion reactor, present statue and future development of ITER/EDA, meanings of ITER under realization of the nuclear fusion energy, and others. And in the latter item, the following reports were published: Nuclear fusion materials engineering and system quantum engineering, dynamic imagination of atom and molecule using pulse snap shot method, laser wake field acceleration and ultra short x-ray pulse generation, development of T-cube laser in JAERI, and others. (G.K.)

  20. Dynamic Performance of High Bypass Ratio Turbine Engines With Water Ingestion

    Science.gov (United States)

    Murthy, S. N. B.

    1996-01-01

    The research on dynamic performance of high bypass turbofan engines includes studies on inlets, turbomachinery and the total engine system operating with air-water mixture; the water may be in vapor, droplet, or film form, and their combinations. Prediction codes (WISGS, WINCOF, WINCOF-1, WINCLR, and Transient Engine Performance Code) for performance changes, as well as changes in blade-casing clearance, have been established and demonstrated in application to actual, generic engines. In view of the continuous changes in water distribution in turbomachinery, the performance of both components and the total engine system must be determined in a time-dependent mode; hence, the determination of clearance changes also requires a time-dependent approach. In general, the performance and clearances changes cannot be scaled either with respect to operating or ingestion conditions. Removal of water prior to phase change is the most effective means of avoiding ingestion effects. Sufficient background has been established to perform definitive, full scale tests on a set of components and a complete engine to establish engine control and operability with various air-water vapor-water mixtures.

  1. Supersonic plasma beams with controlled speed generated by the alternative low power hybrid ion engine (ALPHIE) for space propulsion

    Science.gov (United States)

    Conde, L.; Domenech-Garret, J. L.; Donoso, J. M.; Damba, J.; Tierno, S. P.; Alamillo-Gamboa, E.; Castillo, M. A.

    2017-12-01

    The characteristics of supersonic ion beams from the alternative low power hybrid ion engine (ALPHIE) are discussed. This simple concept of a DC powered plasma accelerator that only needs one electron source for both neutral gas ionization and ion beam neutralization is also examined. The plasma production and space charge neutralization processes are thus coupled in this plasma thruster that has a total DC power consumption of below 450 W, and uses xenon or argon gas as a propellant. The operation parameters of the plasma engine are studied in the laboratory in connection with the ion energy distribution function obtained with a retarding-field energy analyzer. The ALPHIE plasma beam expansion produces a mesothermal plasma flow with two-peaked ion energy distribution functions composed of low and high speed ion groups. The characteristic drift velocities of the fast ion groups, in the range 36.6-43.5 Km/s, are controlled by the acceleration voltage. These supersonic speeds are higher than the typical ion sound velocities of the low energy ion group produced by the expansion of the plasma jet. The temperatures of the slow ion population lead to ion Debye lengths longer than the electron Debye lengths. Furthermore, the electron impact ionization can coexist with collisional ionization by fast ions downstream the grids. Finally, the performance characteristics and comparisons with other plasma accelerator schemes are also discussed.

  2. Performance and exhaust emission characteristics of variable compression ratio diesel engine fuelled with esters of crude rice bran oil.

    Science.gov (United States)

    Vasudeva, Mohit; Sharma, Sumeet; Mohapatra, S K; Kundu, Krishnendu

    2016-01-01

    As a substitute to petroleum-derived diesel, biodiesel has high potential as a renewable and environment friendly energy source. For petroleum importing countries the choice of feedstock for biodiesel production within the geographical region is a major influential factor. Crude rice bran oil is found to be good and viable feedstock for biodiesel production. A two step esterification is carried out for higher free fatty acid crude rice bran oil. Blends of 10, 20 and 40 % by vol. crude rice bran biodiesel are tested in a variable compression ratio diesel engine at compression ratio 15, 16, 17 and 18. Engine performance and exhaust emission parameters are examined. Cylinder pressure-crank angle variation is also plotted. The increase in compression ratio from 15 to 18 resulted in 18.6 % decrease in brake specific fuel consumption and 14.66 % increase in brake thermal efficiency on an average. Cylinder pressure increases by 15 % when compression ratio is increased. Carbon monoxide emission decreased by 22.27 %, hydrocarbon decreased by 38.4 %, carbon dioxide increased by 17.43 % and oxides of nitrogen as NOx emission increased by 22.76 % on an average when compression ratio is increased from 15 to 18. The blends of crude rice bran biodiesel show better results than diesel with increase in compression ratio.

  3. Numerical analysis on the effect of swirl ratios on swirl chamber combustion system of DI diesel engines

    International Nuclear Information System (INIS)

    Wei, Shengli; Wang, Feihu; Leng, Xianyin; Liu, Xin; Ji, Kunpeng

    2013-01-01

    Highlights: • A new swirl chamber combustion system of DI diesel engines is proposed. • The appropriate vortex motion can reduce the wall concentration of mixture. • It has best emissions at swirl ratio of 0.8. • Before spray, the turbulent kinetic energy is primarily controlled by the squish. • After spray, the combustion swirl and reverse squish have a great impact on TKE. - Abstract: In order to improve the spray spatial distribution and promote the mixture quality, enhancing airflow movement in a combustion chamber, a new swirl chamber combustion system in direct injection (DI) diesel engines is proposed. The mixture formation and combustion progress in the cylinder are simulated and investigated at several different swirl ratios by using the AVL-FIRE code. The results show that in view of the fuel/air equivalence ratio distribution, the uniformity of mixture with swirl ratio of 0.2 is better. Before spray injection, the turbulent kinetic energy distribution is primarily controlled by the squish. After spray, the combustion swirl and reverse squish swirl have an effect on temperature distribution and turbulent kinetic energy (TKE) in the cylinder. The NO mass fraction is the lowest at swirl ratio of 0.8 and the highest at swirl ratio of 2.7, while Soot mass fraction is the lowest at swirl ratio of 0.2 and the highest at swirl ratio of 3.2. The appropriate swirl is benefit to improve combustion. To sum up, the emissions at swirl ratio of 0.8 has a better performance in the new combustion system

  4. Genome-scale modeling using flux ratio constraints to enable metabolic engineering of clostridial metabolism in silico.

    Science.gov (United States)

    McAnulty, Michael J; Yen, Jiun Y; Freedman, Benjamin G; Senger, Ryan S

    2012-05-14

    Genome-scale metabolic networks and flux models are an effective platform for linking an organism genotype to its phenotype. However, few modeling approaches offer predictive capabilities to evaluate potential metabolic engineering strategies in silico. A new method called "flux balance analysis with flux ratios (FBrAtio)" was developed in this research and applied to a new genome-scale model of Clostridium acetobutylicum ATCC 824 (iCAC490) that contains 707 metabolites and 794 reactions. FBrAtio was used to model wild-type metabolism and metabolically engineered strains of C. acetobutylicum where only flux ratio constraints and thermodynamic reversibility of reactions were required. The FBrAtio approach allowed solutions to be found through standard linear programming. Five flux ratio constraints were required to achieve a qualitative picture of wild-type metabolism for C. acetobutylicum for the production of: (i) acetate, (ii) lactate, (iii) butyrate, (iv) acetone, (v) butanol, (vi) ethanol, (vii) CO2 and (viii) H2. Results of this simulation study coincide with published experimental results and show the knockdown of the acetoacetyl-CoA transferase increases butanol to acetone selectivity, while the simultaneous over-expression of the aldehyde/alcohol dehydrogenase greatly increases ethanol production. FBrAtio is a promising new method for constraining genome-scale models using internal flux ratios. The method was effective for modeling wild-type and engineered strains of C. acetobutylicum.

  5. EFFECT OF COMPRESSION RATIO ON ENERGY AND EMISSION OF VCR DIESEL ENGINE FUELLED WITH DUAL BLENDS OF BIODIESEL

    Directory of Open Access Journals (Sweden)

    R. D. EKNATH

    2014-10-01

    Full Text Available In recent 10 years biodiesel fuel was studied extensively as an alternative fuel. Most of researchers reported performance and emission of biodiesel and their blends with constant compression ratio. Also all the research was conducted with use of single biodiesel and its blend. Few reports are observed with the use of variable compression ratio and blends of more than one biodiesel. Main aim of the present study is to analyse the effect of compression ratio on the performance and emission of dual blends of biodiesel. In the present study Blends of Jatropha and Karanja with Diesel fuel was tested on single cylinder VCR DI diesel engine for compression ratio 16 and 18. High density of biodiesel fuel causes longer delay period for Jatropha fuel was observed compare with Karanja fuel. However blending of two biodiesel K20J40D results in to low mean gas temperature which is the main reason for low NOx emission.

  6. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    Directory of Open Access Journals (Sweden)

    Nureddin Dinler

    2010-01-01

    Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

  7. Effect of compression ratio on performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas

    International Nuclear Information System (INIS)

    Bora, Bhaskor J.; Saha, Ujjwal K.; Chatterjee, Soumya; Veer, Vijay

    2014-01-01

    Highlights: • Maximum brake thermal efficiency of 20.04% was obtained in dual fuel mode. • Compression ratio of 18 produced the maximum brake thermal efficiency. • Maximum replacement of diesel was found to be 79.46% at a compression ratio of 18. • CO gets reduced by 26.22% with the increase of compression ratio from 16 to18. • HC gets reduced by 41.97% with the increase of compression ratio from 16 to18. - Abstract: The energy consumption of the world is increasing at a staggering rate due to population explosion. The extensive use of energy has led to fossil fuel depletion and the rise in pollution. Renewable energy holds the key solution to these aforementioned problems. Biogas, one such renewable fuel, can be used in a diesel engine under dual fuel mode for the generation of power. This work attempts to unfold the effect of compression ratio on the performance, combustion and emission characteristics of a dual fuel diesel engine run on raw biogas. For this investigation, a 3.5 kW single cylinder, direct injection, water cooled, variable compression ratio diesel engine is converted into a biogas run dual fuel diesel engine by connecting a venturi gas mixer at the inlet manifold. Experiments have been conducted at various compression ratios (18, 17.5, 17 and 16) and under different loading conditions fixing the standard injection timing at 23° before top dead centre. At 100% load, the brake thermal efficiencies of the dual fuel mode are found to be 20.04%, 18.25%, 17.07% and 16.42% at compression ratios of 18, 17.5, 17 and 16, respectively, whereas at the same load, the diesel mode shows an efficiency of 27.76% at a compression ratio of 17.5. The maximum replacement of the precious fossil fuel is found to be 79.46%, 76.1%, 74% and 72% at compression ratios of 18, 17.5, 17 and 16, respectively at 100% load. For the dual fuel mode, on an average, there is a reduction in carbon monoxide as well as hydrocarbon emission by 26.22% and 41.97% when compression

  8. Solid Waste from Four-stroke Medium Speed Engine Power Plant Operation

    OpenAIRE

    Smart, Heidi

    2016-01-01

    This thesis is a study of the solid-state waste generated in power plants based on internal combustion engine (ICE) technology, supplied by the Wärtsilä Energy Solutions division. This thesis, which characterizes and quantifies the waste, was done to enhance the ability of supporting customers in issues related to social and environmental impact assessment, environmental permits, waste management planning, etc. The Performance Standards on Environmental and Social Sustainability and the E...

  9. Emissions from large-scale medium-speed diesel engines: 2. Influence of fuel type and operating mode

    International Nuclear Information System (INIS)

    Sarvi, Arto; Zevenhoven, Ron; Fogelholm, Carl-Johan

    2008-01-01

    This paper addresses gaseous emissions smoke (soot) and particulate matter in large-scale diesel engine exhaust. The test engine was a large-scale turbocharged, after-cooled mean speed (∝ 500 rpm) direct-injection diesel engine and the power per cylinder was about 1 MW. Emission measurements were carried out on burning heavy fuel (HFO) and light fuel (LFO) oils. The test modes for the investigation were a propulsion mode (marine application) and a generator mode (power plant application). Gaseous emissions were measured according to the IMO technical code, smoke (soot) emissions were determined optically and particulate matter (PM) was measured by gravimetric impactor designed for five size fractions. In comparison the emissions from HFO and LFO utilisations indicate slightly higher NO and CO emissions for HFO, while LFO gives clearly higher emissions of hydrocarbons (HC). Emissions of soot and CO appeared to correlate very well, being very high for both fuels throughout the propulsion mode and low load, otherwise being similar for both modes. PM emissions are more than three times higher with HFO than with LFO and appear to decrease with the load except for HFO during the generator mode where an increase of PM emissions with the load is seen. Some data on sampled particles is given. (author)

  10. Kaner biodiesel production through hybrid reactor and its performance testing on a CI engine at different compression ratios

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Yadav

    2017-06-01

    Full Text Available The present study deals with development of a hybrid reactor for biodiesel production based on the combined hydrodynamic cavitation and mechanical stirring processes. Biodiesel were produced using Kaner Seed Oil (KSO. The experimental results show that hybrid reactor produces 95% biodiesel yield within 45 min for 0.75% of catalyst and 6:1 M ratio which is significantly higher as compared to mechanical stirring or hydrodynamic cavitation alone. Thus biodiesel production process in hybrid reactor is cheap (high yield, efficient (time saving and environmentally friendly (lower% of catalyst. Performance study on engine shows that an increase in compression ratios (from 16 to 18 improves the engine performance using biodiesel blends as compared to petroleum diesel.

  11. Theoretical modeling of combustion characteristics and performance parameters of biodiesel in DI diesel engine with variable compression ratio

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dawody, Mohamed F.; Bhatti, S.K. [Department of Mechanical Engineering, Andhra University (India)

    2013-07-01

    Increasing of costly and depleting fossil fuels are prompting researchers to use edible as well as non-edible vegetable oils as a promising alternative to petro-diesel fuels. A comprehensive computer code using ''Quick basic'' language was developed for the diesel engine cycle to study the combustion and performance characteristics of a single cylinder, four stroke, direct injection diesel engine with variable compression ratio. The engine operates on diesel fuel and 20% (mass basis) of biodiesel (derived from soybean oil) blended with diesel. Combustion characteristics such as cylinder pressure, heat release fraction, heat transfer and performance characteristics such as brake power; and brake specific fuel consumption (BSFC) were analyzed. On the basis of the first law of thermodynamics the properties at each degree crank angle was calculated. Wiebe function is used to calculate the instantaneous heat release rate. The computed results are validated through the results obtained in the simulation Diesel-rk software.

  12. Combustion and Emission Characteristics of Variable Compression Ignition Engine Fueled with Jatropha curcas Ethyl Ester Blends at Different Compression Ratio

    Directory of Open Access Journals (Sweden)

    Rajneesh Kumar

    2014-01-01

    Full Text Available Engine performance and emission characteristics of unmodified biodiesel fueled diesel engines are highly influenced by their ignition and combustion behavior. In this study, emission and combustion characteristics were studied when the engine operated using the different blends (B10, B20, B30, and B40 and normal diesel fuel (B0 as well as when varying the compression ratio from 16.5 : 1 to 17.5 : 1 to 18.5 : 1. The change of compression ratio from 16.5 : 1 to 18.5 : 1 resulted in 27.1%, 27.29%, 26.38%, 28.48%, and 34.68% increase in cylinder pressure for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions. Higher peak heat release rate increased by 23.19%, 14.03%, 26.32%, 21.87%, and 25.53% for the blends B0, B10, B20, B30, and B40, respectively, at 75% of rated load conditions, when compression ratio was increased from16.5 : 1 to 18.5 : 1. The delay period decreased by 21.26%, CO emission reduced by 14.28%, and NOx emission increased by 22.84% for B40 blends at 75% of rated load conditions, when compression ratio was increased from 16.5 : 1 to 18.5 : 1. It is concluded that Jatropha oil ester can be used as fuel in diesel engine by blending it with diesel fuel.

  13. Estimation of the in-cylinder air/fuel ratio of an internal combustion engine by the use of pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Tunestaal, Per

    2000-03-01

    This thesis investigates the use of cylinder pressure measurements for estimation of the in-cylinder air/fuel ratio in a spark ignited internal combustion engine. An estimation model which uses the net heat release profile for estimating the cylinder air/fuel ratio of a spark ignition engine is developed. The net heat release profile is computed from the cylinder pressure trace and quantifies the conversion of chemical energy of the reactants in the charge into thermal energy. The net heat release profile does not take heat- or mass transfer into account. Cycle-averaged air/fuel ratio estimates over a range of engine speeds and loads show an RMS error of 4.1% compared to measurements in the exhaust. A thermochemical model of the combustion process in an internal combustion engine is developed. It uses a simple chemical combustion reaction, polynominal fits of internal energy as function of temperature, and the first law of thermodynamics to derive a relationship between measured cylinder pressure and the progress of the combustion process. Simplifying assumptions are made to arrive at an equation which relates the net heat release to the cylinder pressure. Two methods for estimating the sensor offset of a cylinder pressure transducer are developed. Both methods fit the pressure data during the pre-combustion phase of the compression stroke to a polytropic curve. The first method assumes a known polytropic exponent, and the other estimates the polytropic exponent. The first method results in a linear least-squares problem, and the second method results in a nonlinear least-squares problem. The nonlinear least-squares problem is solved by separating out the nonlinear dependence and solving the single-variable minimization problem. For this, a finite difference Newton method is derived. Using this method, the cost of solving the nonlinear least-squares problem is only slightly higher than solving the linear least-squares problem. Both methods show good statistical

  14. Influence of ethanol admixture on the determination of equivalence ratios in DISI engines by laser-induced fluorescence.

    Science.gov (United States)

    Storch, Michael; Lind, Susanne; Will, Stefan; Zigan, Lars

    2016-10-20

    In this work, the planar laser-induced fluorescence of a fuel tracer is applied for the analysis of mixture formation for various ethanol/iso-octane blends in a direct-injection spark-ignition (DISI) engine. The tracer triethylamine (TEA) was added to pure iso-octane and ethanol as well as to their blends E20 and E85 for the measurement of the fuel/air ratio. In general, ethanol blending strongly affects the mixture formation process, which is caused by specific physical fuel properties influencing the evaporation process of ethanol in comparison to iso-octane. As interactions of the fuel and tracer fluorescence appear possible, TEA fluorescence was studied for different fuel blends in a cuvette, in a calibration cell under constant conditions, and in an optically accessible internal combustion engine at late injection timing. It was found that ethanol blending strongly affects the fluorescence intensity of TEA in the liquid phase, which can be explained by the interaction of the tracer and ethanol molecules. However, in the gas phase a quantification of the fuel/air ratio is possible for different ethanol fuel blends, which is demonstrated in a DISI engine. Under stratified charge conditions the engine results showed a significant impact of a high amount of ethanol on the mixture formation process, leading to a leaner mixture in comparison to iso-octane.

  15. Advancing the speed, sensitivity and accuracy of biomolecular detection using multi-length-scale engineering

    Science.gov (United States)

    Kelley, Shana O.; Mirkin, Chad A.; Walt, David R.; Ismagilov, Rustem F.; Toner, Mehmet; Sargent, Edward H.

    2014-12-01

    Rapid progress in identifying disease biomarkers has increased the importance of creating high-performance detection technologies. Over the last decade, the design of many detection platforms has focused on either the nano or micro length scale. Here, we review recent strategies that combine nano- and microscale materials and devices to produce large improvements in detection sensitivity, speed and accuracy, allowing previously undetectable biomarkers to be identified in clinical samples. Microsensors that incorporate nanoscale features can now rapidly detect disease-related nucleic acids expressed in patient samples. New microdevices that separate large clinical samples into nanocompartments allow precise quantitation of analytes, and microfluidic systems that utilize nanoscale binding events can detect rare cancer cells in the bloodstream more accurately than before. These advances will lead to faster and more reliable clinical diagnostic devices.

  16. Improving efficiency of two-type maximum power point tracking methods of tip-speed ratio and optimum torque in wind turbine system using a quantum neural network

    International Nuclear Information System (INIS)

    Ganjefar, Soheil; Ghassemi, Ali Akbar; Ahmadi, Mohamad Mehdi

    2014-01-01

    In this paper, a quantum neural network (QNN) is used as controller in the adaptive control structures to improve efficiency of the maximum power point tracking (MPPT) methods in the wind turbine system. For this purpose, direct and indirect adaptive control structures equipped with QNN are used in tip-speed ratio (TSR) and optimum torque (OT) MPPT methods. The proposed control schemes are evaluated through a battery-charging windmill system equipped with PMSG (permanent magnet synchronous generator) at a random wind speed to demonstrate transcendence of their effectiveness as compared to PID controller and conventional neural network controller (CNNC). - Highlights: • Using a new control method to harvest the maximum power from wind energy system. • Using an adaptive control scheme based on quantum neural network (QNN). • Improving of MPPT-TSR method by direct adaptive control scheme based on QNN. • Improving of MPPT-OT method by indirect adaptive control scheme based on QNN. • Using a windmill system based on PMSG to evaluate proposed control schemes

  17. 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.

  18. Design study and performance analysis of a high-speed multistage variable-geometry fan for a variable cycle engine

    Science.gov (United States)

    Sullivan, T. J.; Parker, D. E.

    1979-01-01

    A design technology study was performed to identify a high speed, multistage, variable geometry fan configuration capable of achieving wide flow modulation with near optimum efficiency at the important operating condition. A parametric screening study of the front and rear block fans was conducted in which the influence of major fan design features on weight and efficiency was determined. Key design parameters were varied systematically to determine the fan configuration most suited for a double bypass, variable cycle engine. Two and three stage fans were considered for the front block. A single stage, core driven fan was studied for the rear block. Variable geometry concepts were evaluated to provide near optimum off design performance. A detailed aerodynamic design and a preliminary mechanical design were carried out for the selected fan configuration. Performance predictions were made for the front and rear block fans.

  19. Leaching of boron, arsenic and selenium from sedimentary rocks: I. Effects of contact time, mixing speed and liquid-to-solid ratio

    Energy Technology Data Exchange (ETDEWEB)

    Tabelin, Carlito Baltazar, E-mail: carlito@trans-er.eng.hokudai.ac.jp [Laboratory of Soil Environment Engineering, Faculty of Engineering, Hokkaido University, Sapporo (Japan); Hashimoto, Ayaka, E-mail: a.hashimoto@diaconsult.co.jp [DIA Consultants Co. Ltd., Sapporo (Japan); Igarashi, Toshifumi, E-mail: tosifumi@eng.hokudai.ac.jp [Laboratory of Groundwater and Mass Transport, Faculty of Engineering, Hokkaido University, Sapporo (Japan); Yoneda, Tetsuro, E-mail: yonet@eng.hokudai.ac.jp [Laboratory of Soil Environment Engineering, Faculty of Engineering, Hokkaido University, Sapporo (Japan)

    2014-02-01

    Sedimentary rocks of marine origin excavated in tunnel projects were recently identified as potentially hazardous because they could release significant amounts of toxic trace elements when exposed to the environment. This study investigated the leaching characteristics of B, As, Se and the major coexisting ions under various conditions to identify the factors and processes controlling their evolution in the leachate. In addition, we evaluated whether the parameters of the currently used leachability test for excavated rocks were adequate. Although the leachabilities of B, As and Se similarly increased at longer contact times, only those of B and As were influenced by the mixing speed and/or liquid-to-solid ratio (L/S). The majority of trace elements dissolved in the leachate originated from the dissolution of soluble salts formed from seawater of the Cretaceous trapped during the formation of the sedimentary rocks. Moreover, the alkaline pH of the leachates could be attributed to the simultaneous dissolutions at varying degrees of the mineral components of the rocks as well as the precipitation of clay minerals. In the leaching test of excavated rocks for regulatory purposes, the best values of contact time and mixing speed should represent conditions of the highest trace element extractabilities, which in this study were found at longer contact times ( > 48 h) and the fastest mixing speed (200 rpm). The most appropriate L/S for the leaching test is 10 because it was around this L/S that the extractabilities and leaching concentrations of the trace elements were simultaneously observed at their highest values. - Highlights: • B, As and Se leaching increased with time reaching equilibrium after ca. 48 h. • Effect of L/S on B and As leaching was strong but not that much on Se. • All leachates were alkaline regardless of the contact time, mixing speed and L/S. • Na{sup +}–SO{sub 4}{sup 2−} and Na{sup +}–HCO{sub 3}{sup −} type leachates were produced

  20. The Promise and Challenges of Ultra High Bypass Ratio Engine Technology and Integration

    Science.gov (United States)

    Hughes, Chris

    2011-01-01

    In this presentation, an overview of the research being conducted by the ERA Project in Ultra High Bypass aircraft propulsion and in partnership with Pratt & Whitney with their Geared TurboFan (GTF) is given. The ERA goals are shown followed by a discussion of what areas need to be addressed on the engine to achieve the goals and how the GTF is uniquely qualified to meet the goals through a discussion of what benefits the cycle provides. The first generation GTF architecture is then shown highlighting the areas of collaboration with NASA, and the fuel burn, noise and emissions reductions possible based on initial static ground test and flight test data of the first GTF engine. Finally, a 5 year technology roadmap is presented focusing on Ultra High Bypass propulsion technology research areas that are being pursued and being planned by ERA and P&W under their GTF program.

  1. The influence of air-fuel ratio on mixture parameters in port fuel injection engines

    Directory of Open Access Journals (Sweden)

    Adrian Irimescu

    2008-10-01

    Full Text Available Nowadays, research in the internal combustion engine field is focusing on detailed understanding of the processes that take place in certain parts of the aggregate, and can have a great influence on the engine’s performance and pollution levels. Such research is developed in this paper, in which using a numerical method based on the i-x air-fuel diagram, one can simulate a series of values for pressure, temperature and intake air humidity before and after mixture formation takes place in a spark ignition engine inlet port. The aim is to evaluate the final temperature of the air-fuel mixture near the inlet valve and evaluating the main factors of influence on the homogeneity of the mixture.

  2. System and method of cylinder deactivation for optimal engine torque-speed map operation

    Science.gov (United States)

    Sujan, Vivek A; Frazier, Timothy R; Follen, Kenneth; Moon, Suk-Min

    2014-11-11

    This disclosure provides a system and method for determining cylinder deactivation in a vehicle engine to optimize fuel consumption while providing the desired or demanded power. In one aspect, data indicative of terrain variation is utilized in determining a vehicle target operating state. An optimal active cylinder distribution and corresponding fueling is determined from a recommendation from a supervisory agent monitoring the operating state of the vehicle of a subset of the total number of cylinders, and a determination as to which number of cylinders provides the optimal fuel consumption. Once the optimal cylinder number is determined, a transmission gear shift recommendation is provided in view of the determined active cylinder distribution and target operating state.

  3. Air fuel ratio detector corrector for combustion engines using adaptive neurofuzzy networks

    Directory of Open Access Journals (Sweden)

    Nidhi Arora

    2013-07-01

    Full Text Available A perfect mix of the air and fuel in internal combustion engines is desirable for proper combustion of fuel with air. The vehicles running on road emit harmful gases due to improper combustion. This problem is severe in heavy vehicles like locomotive engines. To overcome this problem, generally an operator opens or closes the valve of fuel injection pump of locomotive engines to control amount of air going inside the combustion chamber, which requires constant monitoring. A model is proposed in this paper to alleviate combustion process. The method involves recording the time-varying flow of fuel components in combustion chamber. A Fuzzy Neural Network is trained for around 40 fuels to ascertain the required amount of air to form a standard mix to produce non-harmful gases and about 12 fuels are used for testing the network’s performance. The network then adaptively determines the additional/subtractive amount of air required for proper combustion. Mean square error calculation ensures the effectiveness of the network’s performance.

  4. Fast predictive control for air-fuel ratio of SI engines using a ...

    African Journals Online (AJOL)

    In this paper MPC based on an adaptive neural network model is attempted for air fuel ratio (AFR), in which the model is adapted on-line to cope with nonlinear dynamics and parameter uncertainties. A radial basis function (RBF) network is employed and the recursive least squares (RLS) algorithm is used for weight ...

  5. Review of criteria for the selection of probability distributions for wind speed data and introduction of the moment and L-moment ratio diagram methods, with a case study

    International Nuclear Information System (INIS)

    Ouarda, T.B.M.J.; Charron, C.; Chebana, F.

    2016-01-01

    Highlights: • Review of criteria used to select probability distributions to model wind speed data. • Classical and L-moment ratio diagrams are applied to wind speed data. • The diagrams allow to select the best distribution to model each wind speed sample. • The goodness-of-fit statistics are more consistent with the L-moment ratio diagram. - Abstract: This paper reviews the different criteria used in the field of wind energy to compare the goodness-of-fit of candidate probability density functions (pdfs) to wind speed records, and discusses their advantages and disadvantages. The moment ratio and L-moment ratio diagram methods are also proposed as alternative methods for the choice of the pdfs. These two methods have the advantage of allowing an easy comparison of the fit of several pdfs for several time series (stations) on a single diagram. Plotting the position of a given wind speed data set in these diagrams is instantaneous and provides more information than a goodness-of-fit criterion since it provides knowledge about such characteristics as the skewness and kurtosis of the station data set. In this paper, it is proposed to study the applicability of these two methods for the selection of pdfs for wind speed data. Both types of diagrams are used to assess the fit of the pdfs for wind speed series in the United Arab Emirates. The analysis of the moment ratio diagrams reveals that the Kappa, Log-Pearson type III and Generalized Gamma are the distributions that fit best all wind speed series. The Weibull represents the best distribution among those with only one shape parameter. Results obtained with the diagrams are compared with those obtained with goodness-of-fit statistics and a good agreement is observed especially in the case of the L-moment ratio diagram. It is concluded that these diagrams can represent a simple and efficient approach to be used as complementary method to goodness-of-fit criteria.

  6. A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system.

    Science.gov (United States)

    Sun, Kangfeng; Ji, Fenzhu; Yan, Xiaoyu; Jiang, Kai; Yang, Shichun

    2018-01-01

    As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small.

  7. A Soft Sensor-Based Fault-Tolerant Control on the Air Fuel Ratio of Spark-Ignition Engines

    Directory of Open Access Journals (Sweden)

    Yu-Jia Zhai

    2017-01-01

    Full Text Available The air/fuel ratio (AFR regulation for spark-ignition (SI engines has been an essential and challenging control problem for engineers in the automotive industry. The feed-forward and feedback scheme has been investigated in both academic research and industrial application. The aging effect can often cause an AFR sensor fault in the feedback loop, and the AFR control performance will degrade consequently. In this research, a new control scheme on AFR with fault-tolerance is proposed by using an artificial neural network model based on fault detection and compensation, which can provide the satisfactory AFR regulation performance at the stoichiometric value for the combustion process, given a certain level of misreading of the AFR sensor.

  8. Influence of Climatic Factors on the Efficiency of Disposal Metal- Hydride Unit for the Double-Fuel Low-Speed Internal Combustion Engine of Gas Tankers

    OpenAIRE

    Cherednichenko, Oleksandr Costyntunovich; Tkach, Mykhaylo Romanovich

    2017-01-01

    Contemporary tendencies in the development of ship power engineering have been analyzed. Consideration was given to the specific features of the transportation of liquefied natural gas by gas tankers. The prospects of utilization of the secondary energy resources of marine double-fuel low-speed diesel engines were defined. The metal hydride units of a continuous action were offered for this purpose. The need for the estimation of the influence of climatic factors on the efficiency of disposal...

  9. Emulation study on system characteristic of high pressure common-rail fuel injection system for marine medium-speed diesel engine

    Science.gov (United States)

    Wang, Qinpeng; Yang, Jianguo; Xin, Dong; He, Yuhai; Yu, Yonghua

    2018-05-01

    In this paper, based on the characteristic analyzing of the mechanical fuel injection system for the marine medium-speed diesel engine, a sectional high-pressure common rail fuel injection system is designed, rated condition rail pressure of which is 160MPa. The system simulation model is built and the performance of the high pressure common rail fuel injection system is analyzed, research results provide the technical foundation for the system engineering development.

  10. Application of laminar flow control to high-bypass-ratio turbofan engine nacelles

    Science.gov (United States)

    Wie, Y. S.; Collier, F. S., Jr.; Wagner, R. D.

    1991-01-01

    Recently, the concept of the application of hybrid laminar flow to modern commercial transport aircraft was successfully flight tested on a Boeing 757 aircraft. In this limited demonstration, in which only part of the upper surface of the swept wing was designed for the attainment of laminar flow, significant local drag reduction was measured. This paper addresses the potential application of this technology to laminarize the external surface of large, modern turbofan engine nacelles which may comprise as much as 5-10 percent of the total wetted area of future commercial transports. A hybrid-laminar-flow-control (HLFC) pressure distribution is specified and the corresponding nacelle geometry is computed utilizing a predictor/corrector design method. Linear stability calculations are conducted to provide predictions of the extent of the laminar boundary layer. Performance studies are presented to determine potential benefits in terms of reduced fuel consumption.

  11. The Uncontrolled Economic Engine of the Developing Economies, Speeding up the Climate Shift

    Science.gov (United States)

    Khan, K. M.; Khan, M. A.

    2014-12-01

    As we progress into the 21st century, the world faces challenges of truly global nature bearing implications on the whole world in one way or another. The global economic engine has shifted from the western world (Developed Economies) to the eastern world (Developing Economies) which has brought about tremendous change in the climate related variables in this part of the world. As uncontrolled carbon emissions grow in the developing economies, the phenomenon of global warming and climate shifts become more and more prevalent. While this economic activity provides income for millions of households, it is contributing generously to the rapid degradation of the environment. Developing economies as it has been seen do not employ or abide by stringent regulations regarding emissions which result in uncontrolled emissions. In this particular scenario, it is a tedious task to convince governments in the developing economies to implement regulations regarding emissions because businesses in these economies deem such regulations to be economically unviable. The other side of the problem is that these uncontrolled emission are causing evident climate shifts which has had adverse impacts on the agricultural societies where shifting climates are leading to reduced agricultural output and productivity. Consequently the lives of millions associated directly or indirectly with agriculture are affected and on a more global level, the agricultural produce is decreasing which increases the chances of famine in parts of the world. The situation could have devastating impacts on the global economy and environmental standards and therefore needs to be addressed on emergency basis. The first step towards betterment could be the introduction of the carbon trading economy in the developing economies which would incentivize emission reduction and become more attractive and in the process sustaining minimum possible damage to the environment. Though carbon trading is a formidable first step

  12. Judging a man by the width of his face: the role of facial ratios and dominance in mate choice at speed-dating events.

    Science.gov (United States)

    Valentine, Katherine A; Li, Norman P; Penke, Lars; Perrett, David I

    2014-03-01

    Previous research has shown that men with higher facial width-to-height ratios (fWHRs) have higher testosterone and are more aggressive, more powerful, and more financially successful. We tested whether they are also more attractive to women in the ecologically valid mating context of speed dating. Men's fWHR was positively associated with their perceived dominance, likelihood of being chosen for a second date, and attractiveness to women for short-term, but not long-term, relationships. Perceived dominance (by itself and through physical attractiveness) mediated the relationship between fWHR and attractiveness to women for short-term relationships. Furthermore, men's perceptions of their own dominance showed patterns of association with mating desirability similar to those of fWHR. These results support the idea that fWHR is a physical marker of dominance. This is the first study to show that male dominance and higher fWHRs are attractive to women for short-term relationships in a controlled and interactive situation that could actually lead to mating and dating.

  13. A RCCI operational limits assessment in a medium duty compression ignition engine using an adapted compression ratio

    International Nuclear Information System (INIS)

    Benajes, Jesús; Pastor, José V.; García, Antonio; Boronat, Vicente

    2016-01-01

    Highlights: • RCCI with CR 12.75 reaches up to 80% load fulfilling mechanical limits. • Ultra-low levels in NOx and soot emissions are obtained in the whole engine map. • Ultra-high levels of CO and uHC have been measured overall at low load. • RCCI improves fuel consumption from 25% to 80% engine loads comparing with CDC. - Abstract: Reactivity Controlled Compression Ignition concept offers an ultra-low nitrogen oxide and soot emissions with a high thermal efficiency. This work investigates the capabilities of this low temperature combustion concept to work on the whole map of a medium duty engine proposing strategies to solve its main challenges. In this sense, an extension to high loads of the concept without exceeding mechanical stress as well as a mitigation of carbon oxide and unburned hydrocarbons emissions at low load together with a fuel consumption penalty have been identified as main Reactivity Controlled Compression Ignition drawbacks. For this purpose, a single cylinder engine derived from commercial four cylinders medium-duty engine with an adapted compression ratio of 12.75 is used. Commercial 95 octane gasoline was used as a low reactivity fuel and commercial diesel as a high reactivity fuel. Thus, the study consists of two different parts. Firstly, the work is focused on the development and evaluation of an engine map trying to achieve the maximum possible load without exceeding a pressure rise rate of 15 bar/CAD. The second part holds on improving fuel consumption and carbon oxide and unburned hydrocarbons emissions at low load. Results suggest that it is possible to achieve up to 80% of nominal conventional diesel combustion engine load without overpassing the constraints of pressure rise rate (below 15 bar/CAD) and maximum pressure peak (below 190 bar) while obtaining ultra-low levels of nitrogen oxide and soot emissions. Regarding low load challenges, it has developed a particular methodology sweeping the gasoline-diesel blend together

  14. Advisory speed limits : should they be expanded or not? Contribution XVth International Study Week Traffic Engineering and safety: Traffic engineering & the Driver, Theme 2: Speed limits and the driver, Venice, 23-28 September 1985.

    NARCIS (Netherlands)

    Wegman, F.C.M.

    1985-01-01

    Advisory speed limits are meant to be used intermittently in situations which are recognised by the road user, while at the same time, not giving a clear suggestion as to the speed which should be sustained. At present advisory speed limits are almost exclusively applied in narrow road curves.

  15. Low-voltage high-speed programming gate-all-around floating gate memory cell with tunnel barrier engineering

    Science.gov (United States)

    Hamzah, Afiq; Ezaila Alias, N.; Ismail, Razali

    2018-06-01

    The aim of this study is to investigate the memory performances of gate-all-around floating gate (GAA-FG) memory cell implementing engineered tunnel barrier concept of variable oxide thickness (VARIOT) of low-k/high-k for several high-k (i.e., Si3N4, Al2O3, HfO2, and ZrO2) with low-k SiO2 using three-dimensional (3D) simulator Silvaco ATLAS. The simulation work is conducted by initially determining the optimized thickness of low-k/high-k barrier-stacked and extracting their Fowler–Nordheim (FN) coefficients. Based on the optimized parameters the device performances of GAA-FG for fast program operation and data retention are assessed using benchmark set by 6 and 8 nm SiO2 tunnel layer respectively. The programming speed has been improved and wide memory window with 30% increment from conventional SiO2 has been obtained using SiO2/Al2O3 tunnel layer due to its thin low-k dielectric thickness. Furthermore, given its high band edges only 1% of charge-loss is expected after 10 years of ‑3.6/3.6 V gate stress.

  16. A Numerical Study of Spray Characteristics in Medium Speed Engine Fueled by Different HFO/n-Butanol Blends

    Directory of Open Access Journals (Sweden)

    Hashem Nowruzi

    2014-01-01

    Full Text Available In the present study, nonreacting and nonevaporating spray characteristics of heavy fuel oil (HFO/n-butanol blends are numerically investigated under two different high pressure injections in medium speed engines. An Eulerian-Lagrangian multiphase scheme is used to simulate blend of C14H30 as HFO and 0%, 10%, 15%, and 20% by volume of n-butanol. OpenFOAM CFD toolbox is modified and implemented to study the effect of different blends of HFO/n-butanol on the spray characteristics at 600 and 1000 bar. To validate the presented simulations, current numerical results are compared against existing experimental data and good compliance is achieved. Based on the numerical findings, addition of n-butanol to HFO increases the particles volume in parcels at 600 bar. It was also found that blend fuels increase the number of spray particles and the average velocity of spray compared to pure HFO. Moreover, under injection pressure of 1000 bar, HFO/n-butanol blends compared to pure HFO fuel decrease particles volume in parcels of spray. Another influence of HFO/n-butanol blends is the decrease in average of particles diameter in parcels. Meanwhile, the effect of HFO/n-butanol on spray length is proved to be negligible. Finally, it can be concluded that higher injection pressure improves the spray efficiency.

  17. A method of encountering the ratio of adjacent sides and its applied study in nuclear engineering survey

    International Nuclear Information System (INIS)

    Wu Jingqin

    1996-01-01

    The cross side or range net survey method is to compute the average error of the measured lengths of sides. With the increment of the side length, the viewing variance increases greatly. Generally the photo-electrical distance survey equipment has a high inside precision, but it is affected by typical weather error so that the outside precision is decreased, and this weather error similar to systematic error greatly decreases the viewing side precision. To solve this problem, theoretical study and field test were carried out for the correlation of ratios among short sides by photo-electrical survey, and the stability degree of the ratios of sides, a new method of ratio encountering of adjacent sides is put forward. Because of the weights of the ration variance σ γ 2 = 2η 2 γ 2 and the angular variance σ β 2 = 2J 2 ρ 2 match each other, so the systematic error can be eliminated completely, and a survey point co-ordinate of high precision can be obtained. It is easy to operate, as it does not require multi-photo-band survey or to operate at the optimal observation time, and is especially suitable to nuclear engineering survey applications. (3 tabs.)

  18. Resonant Vibrations Resulting from the Re-Engineering of a Constant-Speed 2-Bladed Turbine to a Variable-Speed 3-Bladed Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, P.; Wright, A. D.; Finersh, L. J.

    2010-12-01

    The CART3 (Controls Advanced Research Turbine, 3-bladed) at the National Wind Technology Center has recently been converted from a 2-bladed constant speed machine to a 3-bladed variable speed machine designed specically for controls research. The purpose of this conversion was to develop an advanced controls field-testing platform which has the more typical 3-bladed configuration. A result of this conversion was the emergence of several resonant vibrations, some of which initially prevented operation of the turbine until they could be explained and resolved. In this paper, the investigations into these vibrations are presented as 'lessons-learned'. Additionally, a frequency-domain technique called waterfall plotting is discussed and its usefulness in this research is illustrated.

  19. Performance evaluation of an advanced air-fuel ratio controller on a stationary, rich-burn natural gas engine

    Science.gov (United States)

    Kochuparampil, Roshan Joseph

    The advent of an era of abundant natural gas is making it an increasingly economical fuel source against incumbents such as crude oil and coal, in end-use sectors such as power generation, transportation and industrial chemical production, while also offering significant environmental benefits over these incumbents. Equipment manufacturers, in turn, are responding to widespread demand for power plants optimized for operation with natural gas. In several applications such as distributed power generation, gas transmission, and water pumping, stationary, spark-ignited, natural gas fueled internal combustion engines (ICEs) are the power plant of choice (over turbines) owing to their lower equipment and operational costs, higher thermal efficiencies across a wide load range, and the flexibility afforded to end-users when building fine-resolution horsepower topologies: modular size increments ranging from 100 kW -- 2 MW per ICE power plant compared to 2 -- 5 MW per turbine power plant. Under the U.S. Environment Protection Agency's (EPA) New Source Performance Standards (NSPS) and Reciprocating Internal Combustion Engine National Emission Standards for Hazardous Air Pollutants (RICE NESHAP) air quality regulations, these natural gas power plants are required to comply with stringent emission limits, with several states mandating even stricter emissions norms. In the case of rich-burn or stoichiometric natural gas ICEs, very high levels of sustained emissions reduction can be achieved through exhaust after-treatment that utilizes Non Selective Catalyst Reduction (NSCR) systems. The primary operational constraint with these systems is the tight air-fuel ratio (AFR) window of operation that needs to be maintained if the NSCR system is to achieve simultaneous reduction of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), volatile organic compounds (VOCs), and formaldehyde (CH 2O). Most commercially available AFR controllers utilizing lambda (oxygen

  20. An experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine

    OpenAIRE

    Machrafi, Hatim; Cavadias

    2008-01-01

    In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured, The inlet temperature was changed from 25 to 70 degrees C and the equivalence ratio from 0.18 to 0.41, while the compression ratio varied from 6 to 13.5. The fuels t...

  1. A data processing method for determining instantaneous angular speed and acceleration of crankshaft in an aircraft engine-propeller system using a magnetic encoder

    Science.gov (United States)

    Yu, S. D.; Zhang, X.

    2010-05-01

    This paper presents a method for determining the instantaneous angular speed and instantaneous angular acceleration of the crankshaft in a reciprocating engine and propeller dynamical system from electrical pulse signals generated by a magnetic encoder. The method is based on accurate determination of the measured global mean angular speed and precise values of times when leading edges of individual magnetic teeth pass through the magnetic sensor. Under a steady-state operating condition, a discrete deviation time vs. shaft rotational angle series of uniform interval is obtained and used for accurate determination of the crankshaft speed and acceleration. The proposed method for identifying sub- and super-harmonic oscillations in the instantaneous angular speeds and accelerations is new and efficient. Experiments were carried out on a three-cylinder four-stroke Saito 450R model aircraft engine and a Solo propeller in connection with a 64-teeth Admotec KL2202 magnetic encoder and an HS-4 data acquisition system. Comparisons with an independent data processing scheme indicate that the proposed method yields noise-free instantaneous angular speeds and is superior to the finite difference based methods commonly used in the literature.

  2. Experimental investigation of hydrogen energy share improvement in a compression ignition engine using water injection and compression ratio reduction

    International Nuclear Information System (INIS)

    Chintala, V.; Subramanian, K.A.

    2016-01-01

    Highlights: • Energy efficiency (EE) increased with increase in hydrogen (H_2) energy share. • H_2 energy share increased from 19% to 79% with combined CR reduction and water. • In-cylinder temperature decreased significantly with water addition and CR reduction. • HC, CO, smoke and NO_x emissions with water and CR are lower than base diesel. - Abstract: This study deals with the effect of water addition on enhancement of maximum hydrogen energy share in a compression ignition engine (7.4 kW rated power at 1500 rpm) under dual fuel mode. The specific water consumption (SWC) was varied from 130 to 480 g/kW h in step of 70 g/kW h using manifold and port injection methods. Subsequently, the combined effect of reduction of compression ratio (CR) of the engine (from 19.5:1 (base) to 16.5:1 and 15.4:1) along with water addition on further enhancement of hydrogen energy share is investigated. The hydrogen energy share was limited to 18.8% with conventional dual fuel mode due to knocking. However, the energy share increased to 66.5% with water addition (maximum SWC: 480 g/kW h), and 79% with combined control strategies (SWC of 340 g/kW h and CR reduction to 16.5:1). Thermal efficiency of the engine under water added dual fuel mode is higher than base diesel mode (single fuel mode), but it is lower than the conventional dual fuel mode without water. The efficiency of the engine with reduced CR and water addition is lower than the conventional dual fuel mode, however at the CR of 16.5:1 and SWC of 340 g/kW h, the efficiency is comparable with base diesel mode efficiency. Hydrocarbon, carbon monoxide, smoke, and oxides of nitrogen emissions of the engine with water addition (340 g/kW h) and CR reduction (to 16.5:1) decreased significantly as compared to base diesel mode, but slightly higher than conventional dual fuel mode.

  3. Performance and Durability Assessment of Two Emission Control Technologies Installed on a Legacy High-Speed Marine Diesel Engine

    Science.gov (United States)

    2015-11-05

    Machinery Research and Engineering Dept., Philadelphia, PA, USA. 2. University of California Riverside (UCR), Bourns College of Engineering-Center for...Research and Engineering Dept., Philadelphia, PA, USA. 2. University of California Riverside (UCR), Bourns College of Engineering-Center for Environmental...four Detroit Diesel Corporation ( DDC ) 71-series 12-cylinder engines – two for propulsion and two for power generation (Jane’s 2001). Investigating

  4. Effect of Variable Compression Ratio on Performance of a Diesel Engine Fueled with Karanja Biodiesel and its Blends

    Science.gov (United States)

    Mishra, Rahul Kumar; soota, Tarun, Dr.; singh, Ranjeet

    2017-08-01

    Rapid exploration and lavish consumption of underground petroleum resources have led to the scarcity of underground fossil fuels moreover the toxic emissions from such fuels are pernicious which have increased the health hazards around the world. So the aim was to find an alternative fuel which would meet the requirements of petroleum or fossil fuels. Biodiesel is a clean, renewable and bio-degradable fuel having several advantages, one of the most important of which is being its eco-friendly and better knocking characteristics than diesel fuel. In this work the performance of Karanja oil was analyzed on a four stroke, single cylinder, water cooled, variable compression ratio diesel engine. The fuel used was 5% - 25% karanja oil methyl ester by volume in diesel. The results such obtained are compared with standard diesel fuel. Several properties i.e. Brake Thermal Efficiency, Brake Specific Fuel Consumptions, Exhaust Gas Temperature are determined at all operating conditions & at variable compression ratio 17 and 17.5.

  5. Experimental study on the natural gas dual fuel engine test and the higher the mixture ratio of hydrogen to natural gas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B.S.; Lee, Y.S.; Park, C.K. [Cheonnam University, Kwangju (Korea); Masahiro, S. [Kyoto University, Kyoto (Japan)

    1999-05-28

    One of the unsolved problems of the natural gas dual fuel engine is that there is too much exhaust of Total Hydrogen Carbon(THC) at a low equivalent mixture ratio. To fix it, a natural gas mixed with hydrogen was applied to engine test. The results showed that the higher the mixture ratio of hydrogen to natural gas, the higher the combustion efficiency. And when the amount of the intake air is reached to 90% of WOT, the combustion efficiency was promoted. But, like a case making the injection timing earlier, the equivalent mixture ratio for the nocking limit decreases and the produce of NOx increases. 5 refs., 9 figs., 1 tab.

  6. Investigation on the effects of pilot injection on low temperature combustion in high-speed diesel engine fueled with n-butanol–diesel blends

    International Nuclear Information System (INIS)

    Huang, Haozhong; Liu, Qingsheng; Yang, Ruzhi; Zhu, Tianru; Zhao, Ruiqing; Wang, Yaodong

    2015-01-01

    Highlights: • The effects of pre-injected timing and pre-injected mass were studied in CI engine. • The addition of n-butanol consumed OH free radicals, which delayed the ignition time. • With the increase of n-butanol, the BSFC and MPRR increased, NO_x and soot decreased. • With the advance of pilot injection timing, the BSFC increased, NO_x and soot decreased. • With the increase of pilot injection mass, NO_x increased, soot decreased then increased. - Abstract: The effect of pilot injection timing and pilot injection mass on combustion and emission characteristics under medium exhaust gas recirculation (EGR (25%)) condition were experimentally investigated in high-speed diesel engine. Diesel fuel (B0), two blends of butanol and diesel fuel denoted as B20 (20% butanol and 80% diesel in volume), and B30 (30% butanol and 70% diesel in volume) were tested. The results show that, for all fuels, when advancing the pilot injection timing, the peak value of heat release rate decreases for pre-injection fuel, but increases slightly for the main-injection fuel. Moreover, the in-cylinder pressure peak value reduces with the rise of maximum pressure rise rate (MPRR), while NO_x and soot emissions reduce. Increasing the pilot injection fuel mass, the peak value of heat release rate for pre-injected fuel increases, but for the main-injection, the peak descends, and the in-cylinder pressure peak value and NO_x emissions increase, while soot emission decreases at first and then increases. Blending n-butanol in diesel improves soot emissions. When pilot injection is adopted, the increase of n-butanol ratio causes the MPRR increasing and the crank angle location for 50% cumulative heat release (CA50) advancing, as well as NO_x and soot emissions decreasing. The simulation of the combustion of n-butanol–diesel fuel blends, which was based on the n-heptane–n-butanol–PAH–toluene mixing mechanism, demonstrated that the addition of n-butanol consumed OH free radicals

  7. The effect of product quality on the integrity of advanced surface engineering treatments applied to high speed steel circular saw blades

    International Nuclear Information System (INIS)

    Bradbury, S.R.; Sarwar, M.

    1996-01-01

    Advanced surface engineering technologies have been successfully applied to high speed steel drills and carbide single-point cutting tools, but, as yet, limited benefits have been realized when applying the same technologies to multi-point cutting tools of commercial quality. This paper discusses the factors that have limited the benefits of advanced surface engineering treatments when applied to high speed steel circular saw blades. Common manufacturing defects have been identified on the teeth of the blades. Tests which evaluate the blade performance throughout its useful life and examination by scanning electron microscopy (SEM) have shown that these defects adversely affect the performance and wear resistance of surface engineered blades. Further investigations suggest that significant improvements in coating integrity can be achieved through the careful preparation of the substrate surface and refinement of the cutting edge geometry prior to treatment. For this application, the need for refinement and enhancement of current manufacturing practices is demonstrated if the full benefits of advanced surface engineering are to be realized. (orig.)

  8. Tracer-based laser-induced fluorescence measurement technique for quantitative fuel/air-ratio measurements in a hydrogen internal combustion engine.

    Science.gov (United States)

    Blotevogel, Thomas; Hartmann, Matthias; Rottengruber, Hermann; Leipertz, Alfred

    2008-12-10

    A measurement technique for the quantitative investigation of mixture formation processes in hydrogen internal combustion engines (ICEs) has been developed using tracer-based laser-induced fluorescence (TLIF). This technique can be employed to fired and motored engine operation. The quantitative TLIF fuel/air-ratio results have been verified by means of linear Raman scattering measurements. Exemplary results of the simultaneous investigation of mixture formation and combustion obtained at an optical accessible hydrogen ICE are shown.

  9. Investigation and modelling of a diesel engine in order to identify combustion characteristics from the engine speed; Untersuchung und Modellierung eines Dieselmotors zur Bestimmung von Verbrennungsmerkmalen aus der Motordrehzahl

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, T.

    2008-07-01

    The author attempted to derive cylinder-selective combustion characteristics from the rotational speed of aninternal combustion engine which should be applicable as control variables for combustion control. Physical models of the components of a four-cylinder diesel engine were developed. Simulations, rotary vibration measurements and cylinder pressure indexing were used for quantitative assessment of external momenta at the crankshaft which are interfering variables in speed-based identification of combustion charcteristics. In particular, the dynamics of control drive and secondary aggregate drive are regarded as well as nonlinear mechanical effects. Further, the influence of intrinsic vibrations of the crankshaft is investigated. On the basis of the models developed here, a method is presented for determining the cylinder-selective combustion characteristics and cylinder momentum by comparing the models. (orig.)

  10. Discrete sliding mode control for engine idle speed%离散滑模控制在发动机怠速设计中的应用

    Institute of Scientific and Technical Information of China (English)

    郭兴进; 刘珺

    2009-01-01

    A novel discrete sliding mode(DSM)controller is designed. Engine idle speed can be controlled by a nonlinear model for the idle speed control(ISC)system of a 4-cylinder, 4-1itre engine. The experimental results show that DSM control system has superior performance on tracking the desired idle speed and rejecting the system disturbances when compared with the existing controller.%利用一种新的离散滑模控制方法, 设计了发动机怠速的离散滑模(DSM)控制器, 用已开发出的4缸、1.4L的AJR发动机怠速控制系统的非线性模型进行发动机怠速转速的控制. 实验结果表明, 与原机的控制器相比较而言, DSM控制器在跟踪期望怠速转速及抗干扰等方面具有优良的性能.

  11. Determination of Optimum Compression Ratio: A Tribological Aspect

    Directory of Open Access Journals (Sweden)

    L. Yüksek

    2013-12-01

    Full Text Available Internal combustion engines are the primary energy conversion machines both in industry and transportation. Modern technologies are being implemented to engines to fulfill today's low fuel consumption demand. Friction energy consumed by the rubbing parts of the engines are becoming an important parameter for higher fuel efficiency. Rate of friction loss is primarily affected by sliding speed and the load acting upon rubbing surfaces. Compression ratio is the main parameter that increases the peak cylinder pressure and hence normal load on components. Aim of this study is to investigate the effect of compression ratio on total friction loss of a diesel engine. A variable compression ratio diesel engine was operated at four different compression ratios which were "12.96", "15:59", "18:03", "20:17". Brake power and speed was kept constant at predefined value while measuring the in- cylinder pressure. Friction mean effective pressure ( FMEP data were obtained from the in cylinder pressure curves for each compression ratio. Ratio of friction power to indicated power of the engine was increased from 22.83% to 37.06% with varying compression ratio from 12.96 to 20:17. Considering the thermal efficiency , FMEP and maximum in- cylinder pressure optimum compression ratio interval of the test engine was determined as 18.8 ÷ 19.6.

  12. An experimental and numerical analysis of the influence of the inlet temperature, equivalence ratio and compression ratio on the HCCI auto-ignition process of Primary Reference Fuels in an engine

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert (France); Cavadiasa, Simeon [UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert (France)

    2008-11-15

    In order to understand better the auto-ignition process in an HCCI engine, the influence of some important parameters on the auto-ignition is investigated. The inlet temperature, the equivalence ratio and the compression ratio were varied and their influence on the pressure, the heat release and the ignition delays were measured. The inlet temperature was changed from 25 to 70 C and the equivalence ratio from 0.18 to 0.41, while the compression ratio varied from 6 to 13.5. The fuels that were investigated were PRF40 and n-heptane. These three parameters appeared to decrease the ignition delays, with the inlet temperature having the least influence and the compression ratio the most. A previously experimentally validated reduced surrogate mechanism, for mixtures of n-heptane, iso-octane and toluene, has been used to explain observations of the auto-ignition process. The same kinetic mechanism is used to better understand the underlying chemical and physical phenomena that make the influence of a certain parameter change according to the operating conditions. This can be useful for the control of the auto-ignition process in an HCCI engine. (author)

  13. Experimental investigation on the availability, performance, combustion and emission distinctiveness of bael oil/ diesel/ diethyl ether blends powered in a variable compression ratio diesel engine

    Science.gov (United States)

    Krishnamoorthi, M.; Malayalamurthi, R.

    2018-02-01

    The present work aims at experimental investigation on the combined effect of injection timing (IT) and injection pressure (IP) on the performance and emissions characteristics, and exergy analysis of a compression-ignition (CI) engine powered with bael oil blends. The tests were conducted using ternary blends of bael oil, diethyl ether (DEE) and neat diesel (D) at various engine loads at a constant engine speed (1500 rpm). With B2 (60%D + 30%bael oil+10%DEE) fuel, the brake thermal efficiency (BTE) of the engine is augmented by 3.5%, reduction of 4.7% of oxides of nitrogen (NOx) emission has been observed at 100% engine load with 250 bar IP. B2 fuel exhibits 7% lower scale of HC emissions compared to that of diesel fuel at 100% engine load in 23 °bTDC IT. The increment in both cooling water and exhaust gas availabilities lead to increasing exergy efficiency with increasing load. The exergy efficiency of about 62.17% has been recorded by B2 fuel at an injection pressure of 230 IP bar with 100% load. On the whole, B2 fuel displays the best performance and combustion characteristics. It also exhibits better characteristics of emissions level in terms of lower HC, smoke opacity and NOx.

  14. 尖速比对风力发电机发电效率的影响%The influence of tip speed ratio on the wind turbine power generation efficiency

    Institute of Scientific and Technical Information of China (English)

    高峰

    2014-01-01

    This paper adopts the method of combining experimental and numerical analysis, conducts the research in view of tip speed ratio influence factors of the wind generator output performance, by changing the tip speed ratio of wind turbine output power, current, voltage and the influence coefficient of utilization of wind energy analysis, found the tip speed ratio of wind generator output power, current and voltage and the wind energy utilization coefficient influence, provides the reference for the design and manufacturing.%本文采用实验和数值分析相结合的方法,针对影响风力发电机输出性能的尖速比因素进行研究,通过尖速比的变化对风力发电机的输出功率、电流、电压以及风能利用系数的影响分析,找到了尖速比对风力发电机的输出功率、电流、电压以及风能利用系数影响程度,为设计或制造提供参考。

  15. High-Speed Multiplexed Spatiotemporally Resolved Measurements of Exhaust Gas Recirculation Dynamics in a Multi-Cylinder Engine Using Laser Absorption Spectroscopy.

    Science.gov (United States)

    Yoo, Jihyung; Prikhodko, Vitaly; Parks, James E; Perfetto, Anthony; Geckler, Sam; Partridge, William P

    2016-04-01

    The need for more environmentally friendly and efficient energy conversion is of paramount importance in developing and designing next-generation internal combustion (IC) engines for transportation applications. One effective solution to reducing emissions of mono-nitrogen oxides (NOx) is exhaust gas recirculation (EGR), which has been widely implemented in modern vehicles. However, cylinder-to-cylinder and cycle-to-cycle variations in the charge-gas uniformity can be a major barrier to optimum EGR implementation on multi-cylinder engines, and can limit performance, stability, and efficiency. Precise knowledge and fine control over the EGR system is therefore crucial, particularly for optimizing advanced engine concepts such as reactivity controlled compression ignition (RCCI). An absorption-based laser diagnostic was developed to study spatiotemporal charge-gas distributions in an IC engine intake manifold in real-time. The laser was tuned to an absorption band of carbon dioxide (CO2), a standard exhaust-gas marker, near 2.7 µm. The sensor was capable of probing four separate measurement locations simultaneously, and independently analyzing EGR fraction at speeds of 5 kHz (1.2 crank-angle degree (CAD) at 1 k RPM) or faster with high accuracy. The probes were used to study spatiotemporal EGR non-uniformities in the intake manifold and ultimately promote the development of more efficient and higher performance engines. © The Author(s) 2016.

  16. Analysis of injection sprays by means of large high-speed engines under cold and evaporating conditions; Analyse von Einspritzsprays mittelschnelllaufender Grossmotoren unter kalten und verdampfenden Bedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Christian; Pinkert, Fabian; Harndorf, Horst [Rostock Univ. (Germany). Lehrstuhl fuer Kolbenmaschinen und Verbrennungsmotoren; Frobenius, Moritz [AVL Deutschland GmbH, Haimhausen (Germany)

    2011-07-01

    The introduction of future emission limits for marine diesel engines requires an improved understanding of the fuel injection process and mixture formation as well as the development of robust and powerful tools to calculate the emission generation. This publication presents research results of the project partners AVI Deutschland GmbH and Rostock University obtained in the associated project EMI-MINI II. Objective of the experimental part of the work is the fundamental investigation of the mixture formation at cold and evaporative conditions in a high-pressure and high-temperature chamber by means of optical methods. For the measurements, a modem, heavy fuel capable single circuit common-rail injector of a medium speed diesel engine is applied. Based on the experimental results a calibration and validation of spray break-up and evaporation models is done. The models are applied in a specific simulation approach in order to predict engine emissions. Characteristic feature of the chosen approach is the consideration of specific nozzle internal flow conditions as boundary conditions for the spray break-up models and thus for the ignition, combustion and emission generation. The presented results demonstrate that the applied models are very sufficient to calculate injection and mixture formation processes. By comparing calculated engine emissions to experimental results obtained by WTZ Rosslau gGmbH it is shown that the presented simulation approach is capable to predict the impact of varying engine parameters on NO{sub x}- and soot emissions effectively. (orig.)

  17. Numerical Investigation of Injection Timing Influence on Fuel Slip and Influence of Compression Ratio on Knock Occurrence in Conventional Dual Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mario Sremec

    2017-12-01

    Full Text Available Compressed natural gas can be used in diesel engine with great benefits, but because of its low reactivity it is usually used in a so called dual fuel combustion process. Optimal parameters for dual fuel engines are not yet investigated thoroughly which is the motivation for this work. In this work, a numerical study performed in a cycle simulation tool (AVL Boost v2013 on the influence of different injection timings on fuel slip into exhaust and influence of compression ratio on knock phenomena in port injected dual fuel engine was conducted. The introduction of natural gas into the intake port of a diesel engine usually results in some fuel slipping into the exhaust port due to valve overlap. By analysing the simulation results, the injection strategy that significantly decreases the natural gas slip is defined. The knock occurrence study showed that the highest allowed compression ratio that will result in knock free operation of the presented engine is 18 for ambient intake condition, while for charged intake conditions the compression ratio should be lowered to 16.

  18. Investigation of piston bowl geometry and speed effects in a motored HSDI diesel engine using a CFD against a quasi-dimensional model

    International Nuclear Information System (INIS)

    Rakopoulos, C.D.; Kosmadakis, G.M.; Pariotis, E.G.

    2010-01-01

    The present work investigates the effect of varying the combustion chamber geometry and engine rotational speed on the gas flow and temperature field, using a new quasi-dimensional engine simulation model in conjunction with an in-house developed computational fluid dynamics (CFD) code served to validate the predicted in-cylinder flow field and gas temperature distribution calculated by the quasi-dimensional model, for three alternative piston bowl geometries and three rotational speeds. This CFD code can simulate three-dimensional curvilinear domains using the finite volume method in a collocated grid; it solves the generalized transport equation for the conservation of mass, momentum and energy, and incorporates the standard k-ε turbulence model with some slight modifications to introduce the compressibility of a fluid in generalized coordinates. On the other hand, the quasi-dimensional model solves the general transport equation for the conservation of mass and energy by a finite volume method throughout the entire in-cylinder volume, while for the estimation of the flow field a new simplified three dimensional air motion model is used. To compare these two models the in-cylinder spatial and temporal temperature distribution, the mean cylinder pressure diagram, as well as the mean in-cylinder radial and axial velocity are examined, for the three piston bowl geometries and the three speeds, for a high speed direct injection (HSDI) diesel engine operating under motoring conditions. From the comparison of calculated results, it becomes apparent that the two models predict similar in-cylinder temperature distributions and mean air velocity fields at each crank angle, for all cases examined. Thus, it is shown that the quasi-dimensional model with the proposed simplified air motion model is capable of capturing the physical effect of combustion chamber geometry and speed on the in-cylinder velocity and temperature field, while needing significantly lower computing

  19. THE CHANGE OF WORKFLOW PROCESS INDICATORS ACCORDING TO SPEED CHARACTERISTICS WHEN HEATING THE COMPRESSEDAIR AT THE ENTRONCE TO THE PNEUMATIC ENGINE

    Directory of Open Access Journals (Sweden)

    A. Voronkov

    2015-12-01

    Full Text Available Experimental studies of the four-cylinder piston air motor 0/D = 76/77 with a slide air diffuser. There were considered the experimental high-speed characteristics, taking into account the heating of the compressed intake air. Heating of the entering the motor compressed air has a positive effect on the energy, and economic performance of the workflow. The power and torque, increase hourly and specific air flow reduces. There greatly improves the reliability and durability of the pneumatic engine.

  20. Performance and emission characteristics of a turbocharged CNG engine fueled by hydrogen-enriched compressed natural gas with high hydrogen ratio

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Fanhua; Wang, Mingyue; Jiang, Long; Chen, Renzhe; Deng, Jiao; Naeve, Nashay; Zhao, Shuli [State Key Laboratory of Automotive Safety and Energy Tsinghua University, Beijing 100084 (China)

    2010-06-15

    This paper investigates the effect of high hydrogen volumetric ratio of 55% on performance and emission characteristics in a turbocharged lean burn natural gas engine. The experimental data was conducted under various operating conditions including different spark timing, excess air ratio (lambda), and manifold pressure. It is found that the addition of hydrogen at a high volumetric ratio could significantly extend the lean burn limit, improve the engine lean burn ability, decrease burn duration, and yield higher thermal efficiency. The CO, CH{sub 4} emissions were reduced and NO{sub x} emission could be kept an acceptable low level with high hydrogen content under lean burn conditions when ignition timing were optimized. (author)

  1. Predicting Minimum Control Speed on the Ground (VMCG) and Minimum Control Airspeed (VMCA) of Engine Inoperative Flight Using Aerodynamic Database and Propulsion Database Generators

    Science.gov (United States)

    Hadder, Eric Michael

    There are many computer aided engineering tools and software used by aerospace engineers to design and predict specific parameters of an airplane. These tools help a design engineer predict and calculate such parameters such as lift, drag, pitching moment, takeoff range, maximum takeoff weight, maximum flight range and much more. However, there are very limited ways to predict and calculate the minimum control speeds of an airplane in engine inoperative flight. There are simple solutions, as well as complicated solutions, yet there is neither standard technique nor consistency throughout the aerospace industry. To further complicate this subject, airplane designers have the option of using an Automatic Thrust Control System (ATCS), which directly alters the minimum control speeds of an airplane. This work addresses this issue with a tool used to predict and calculate the Minimum Control Speed on the Ground (VMCG) as well as the Minimum Control Airspeed (VMCA) of any existing or design-stage airplane. With simple line art of an airplane, a program called VORLAX is used to generate an aerodynamic database used to calculate the stability derivatives of an airplane. Using another program called Numerical Propulsion System Simulation (NPSS), a propulsion database is generated to use with the aerodynamic database to calculate both VMCG and VMCA. This tool was tested using two airplanes, the Airbus A320 and the Lockheed Martin C130J-30 Super Hercules. The A320 does not use an Automatic Thrust Control System (ATCS), whereas the C130J-30 does use an ATCS. The tool was able to properly calculate and match known values of VMCG and VMCA for both of the airplanes. The fact that this tool was able to calculate the known values of VMCG and VMCA for both airplanes means that this tool would be able to predict the VMCG and VMCA of an airplane in the preliminary stages of design. This would allow design engineers the ability to use an Automatic Thrust Control System (ATCS) as part

  2. Numerical Evaluation ofThe Performance ofA Compression Ignition Cng Engine For Heavy DutyTrucksWithAn Optimum Speed PowerTurbine

    Directory of Open Access Journals (Sweden)

    Alberto A. Boretti

    2011-10-01

    Full Text Available The turbocharged direct injection lean burn Diesel engine is the most efficient engine now in production for transport applications. CNG is an alternative fuel with a better carbon to hydrogen ratio therefore permitting reduced carbon dioxide emissions. It is injected in gaseous form for a much cleaner combustion almost cancelling some of the emissions of the Diesel and it permits a much better energy security within Australia. The paper discusses the best options currently available to convert Diesel engine platforms to CNG, with particular emphasis to the use of these CNG engines within Australia where the refuelling network is scarce. This option is determined in the dual fuel operation with a double injector design that couples a second CNG injector to the Diesel injector. This configuration permits the operation Diesel only or Diesel pilot and CNG main depending on the availability of refuelling stations where the vehicle operates. Results of engine performance simulations are performed for a straight six cylinder 13 litres truck engine with a novel power turbine connected to the crankshaft through a constant variable transmission that may be by-passed when non helpful to increase the fuel economy of the vehicle or when damaging the performances of the after treatment system.

  3. Experimental Investigation of Diffuser Pressure-ratio Control with Shock-positioning Limit on 28-inch Ram-jet Engine

    Science.gov (United States)

    Dunbar, William R; Wentworth, Carl B; Crowl, Robert J

    1957-01-01

    The performance of a control system designed for variable thrust applications was determined in an altitude free-jet facility at various Mach numbers, altitudes and angles of attack for a wide range of engine operation. The results are presented as transient response characteristics for step disturbances in fuel flow and stability characteristics as a function of control constants and engine operating conditions. The results indicate that the control is capable of successful operation over the range of conditions tested, although variations in engine gains preclude optimum response characteristics at all conditions with fixed control constants.

  4. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2008-11-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

  5. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2005-09-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

  6. Durability testing of medium speed diesel engine components designed for operating on coal/water slurry fuel

    Science.gov (United States)

    McDowell, R. E.; Giammarise, A. W.; Johnson, R. N.

    1994-01-01

    Over 200 operating cylinder hours were run on critical wearing engine parts. The main components tested included cylinder liners, piston rings, and fuel injector nozzles for coal/water slurry fueled operation. The liners had no visible indication of scoring nor major wear steps found on their tungsten carbide coating. While the tungsten carbide coating on the rings showed good wear resistance, some visual evidence suggests adhesive wear mode was present. Tungsten carbide coated rings running against tungsten carbide coated liners in GE 7FDL engines exhibit wear rates which suggest an approximate 500 to 750 hour life. Injector nozzle orifice materials evaluated were diamond compacts, chemical vapor deposited diamond tubes, and thermally stabilized diamond. Based upon a total of 500 cylinder hours of engine operation (including single-cylinder combustion tests), diamond compact was determined to be the preferred orifice material.

  7. Experimental evaluation of the effect of compression ratio on performance and emission of SI engine fuelled with gasoline and n-butanol blend at different loads

    Directory of Open Access Journals (Sweden)

    Rinu Thomas

    2016-09-01

    Full Text Available Never ending demand for efficient and less polluting engines have always inspired newer technologies. Extensive study has been done on variable compression ratio, a promising in-cylinder technology, in the recent past. The present work is an experimental investigation to examine the variation of different parameters such as brake thermal efficiency, exhaust gas temperature and emissions with respect to change in compression ratio in a single-cylinder carbureted SI engine at different loads with two different fuels. Experiments were conducted at three different compression ratios (CR = 7:1, 8.5:1 and 10:1. The fuels used in this study are pure gasoline and 20% n-butanol blend (B20 in gasoline. The results showed that brake thermal efficiency increases with CR at all loads. Further, the experimental results showed the scope of improving the part-load efficiency of SI engine by adopting the concept of variable compression ratio (VCR technology, especially when fuels with better anti-knock characteristics are used. The uncertainty analysis of the experiments based on the specifications of the equipment used is also tabulated.

  8. Experimental investigation of particle emissions under different EGR ratios on a diesel engine fueled by blends of diesel/gasoline/n-butanol

    International Nuclear Information System (INIS)

    Huang, Haozhong; Liu, Qingsheng; Wang, Qingxin; Zhou, Chengzhong; Mo, Chunlan; Wang, Xueqiang

    2016-01-01

    Highlights: • The effects of EGR and blend fuels on particulate emission were studied in CI engine. • EGR ⩽ 20%, gasoline or n-butanol increases total particulate number concentration. • EGR ⩾ 30%, gasoline or n-butanol reduces total particulate number concentration. • As EGR ratio increased, the particulate mass concentrations of four fuels increased. • Gasoline or n-butanol increases the ratio of sub-25 nm particles number concentration. - Abstract: The particle emission characteristics of a high-pressure common-rail engine under different EGR conditions were investigated, using pure diesel (D100), diesel/gasoline (with a volume ratio of 70:30, D70G30), diesel/n-butanol (with a volume ratio of 70:30, D70B30) and diesel/gasoline/n-butanol (with a volume ratio of 70:15:15, D70G15B15) for combustion. Our results show that, with increasing EGR ratios, the in-cylinder pressure peak decreases and the heat release is delayed for the combustion of each fuel. At an EGR ratio of 30%, the combustion pressure peaks of D70G30, D70B30, D70G15B15 and D100 have similar values; with an EGR ratio of 40%, the combustion pressure peaks and release rate peaks of D70G30 and D70G15B15 are both lower with respect to D100. For small and medium EGR ratios (⩽20%), after the addition of gasoline and/or n-butanol to the fuel, the total particle number concentration (TPNC) increases, while both the soot emissions and the average geometric size of particles decrease. At large EGR ratios (30% and 40%), the TPNC of D70B30, D70G15B15 and D70G20 compared to D100 are reduced by a maximum amount of 74.7%, 66.7% and 28.6%, respectively. As the EGR ratio increases, the total particle mass concentration increases gradually for all four fuels. Blending gasoline or/and n-butanol into diesel induces an increase in the number concentration of sub-25 nm particles (PN25) which may be harmful in terms of health. However, the PN25 decreases with increasing the EGR ratio for all the tested fuels

  9. Control system and method for a power delivery system having a continuously variable ratio transmission

    Science.gov (United States)

    Frank, Andrew A.

    1984-01-01

    A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.

  10. High-Speed Photography

    International Nuclear Information System (INIS)

    Paisley, D.L.; Schelev, M.Y.

    1998-01-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) copyright 1998 Society of Photo-Optical Instrumentation Engineers

  11. Combined effects of cooled EGR and a higher geometric compression ratio on thermal efficiency improvement of a downsized boosted spark-ignition direct-injection engine

    International Nuclear Information System (INIS)

    Su, Jianye; Xu, Min; Li, Tie; Gao, Yi; Wang, Jiasheng

    2014-01-01

    Highlights: • Experiments for the effects of cooled EGR and two compression ratios (CR) on fuel efficiency were conducted. • The mechanism for the observed fuel efficiency behaviors by cooled EGR and high CR was clarified. • Cooled EGR offers more fuel efficiency improvement than elevating CR from 9.3 to 10.9. • Combining 18–25% cooled EGR with 10.9 CR lead to 2.1–3.5% brake thermal efficiency improvements. - Abstract: The downsized boosted spark-ignition direct-injection (SIDI) engine has proven to be one of the most promising concepts to improve vehicle fuel economy. However, the boosted engine is typically designed at a lower geometric compression ratio (CR) due to the increased knock tendency in comparison to naturally aspirated engines, limiting the potential of improving fuel economy. On the other hand, cooled exhaust gas recirculation (EGR) has drawn attention due to the potential to suppress knock and improve fuel economy. Combing the effects of boosting, increased CR and cooled EGR to further improve fuel economy within acceptable knock tolerance has been investigated using a 2.0 L downsized boosted SIDI engine over a wide range of engine operating conditions from 1000 rpm to 3000 rpm at low to high loads. To clarify the mechanism of this complicated effects, the first law of thermodynamics analysis was conducted with the inputs from GT-Power® engine simulation. Experiment results indicate that cooled EGR provides more brake thermal efficiency improvement than increasing geometric CR from 9.3 to 10.9. The benefit of brake thermal efficiency from the higher CR is limited to low load conditions. The attributes for improving brake thermal efficiency by cooled EGR include reduced heat transfer loss, reduced pumping work and increased ratio of specific heats for all the engine operating conditions, as well as higher degree of constant volume heat release only for the knock-limited high load conditions. The combined effects of 18–25% cooled EGR

  12. Influence of swirl ratio on fuel distribution and cyclic variation under flash boiling conditions in a spark ignition direct injection gasoline engine

    International Nuclear Information System (INIS)

    Yang, Jie; Xu, Min; Hung, David L.S.; Wu, Qiang; Dong, Xue

    2017-01-01

    Highlights: • Influence of swirl on fuel distribution studied using laser induced fluorescence. • Gradient is sufficient for fuel spatial distribution variation analysis. • Close relation between fuel distribution and flame initiation/development. • Quantitative analysis shows high swirl suppresses variation of fuel distribution. • High order modes capable of identifying the distribution fluctuation patterns. - Abstract: One effective way of suppressing the cycle-to-cycle variation in engine is to design a combustion system that is robust to the root causes of engine variation over the entire engine working process. Flash boiling has been demonstrated as an ideal technique to produce stable fuel spray. But the generation of stable intake flow and fuel mixture remains challenging. In this study, to evaluate the capability of enhanced swirl flow to produce repeatable fuel mixture formation, the fuel distribution inside a single cylinder optical engine under two swirl ratios were measured using laser induced fluorescence technique. The swirl ratio was regulated by a swirl control valve installed in one of the intake ports. A 266 nm wavelength laser sheet from a frequency-quadrupled laser was directed into the optical engine through the quartz liner 15 mm below the tip of the spark plug. The fluorescence signal from the polycyclic aromatic hydrocarbon in gasoline was collected by applying a 320–420 nm band pass filter mounted in front of an intensified charge coupled device camera. Test results show that the in-cylinder fuel distribution is strongly influenced by the swirl ratio. Specifically, under high swirl condition, the fuel is mainly concentrated on the left side of the combustion chamber. While under the low swirl flow, fuel is distributed more randomly over the observing plane. This agrees well with the measurements of the stable flame location. Additionally, the cycle-to-cycle variation of the fuel distribution were analyzed. Results show that well

  13. Development of acoustically lined ejector technology for multitube jet noise suppressor nozzles by model and engine tests over a wide range of jet pressure ratios and temperatures

    Science.gov (United States)

    Atvars, J.; Paynter, G. C.; Walker, D. Q.; Wintermeyer, C. F.

    1974-01-01

    An experimental program comprising model nozzle and full-scale engine tests was undertaken to acquire parametric data for acoustically lined ejectors applied to primary jet noise suppression. Ejector lining design technology and acoustical scaling of lined ejector configurations were the major objectives. Ground static tests were run with a J-75 turbojet engine fitted with a 37-tube, area ratio 3.3 suppressor nozzle and two lengths of ejector shroud (L/D = 1 and 2). Seven ejector lining configurations were tested over the engine pressure ratio range of 1.40 to 2.40 with corresponding jet velocities between 305 and 610 M/sec. One-fourth scale model nozzles were tested over a pressure ratio range of 1.40 to 4.0 with jet total temperatures between ambient and 1088 K. Scaling of multielement nozzle ejector configurations was also studied using a single element of the nozzle array with identical ejector lengths and lining materials. Acoustic far field and near field data together with nozzle thrust performance and jet aerodynamic flow profiles are presented.

  14. Air to fuel ratio sensor for internal combustion engine control system; Nainen kikan no nensho seigyoyo kunen hi sensor

    Energy Technology Data Exchange (ETDEWEB)

    Tsuzuki, M.; Kawai, T.; Yamada, T.; Nishio [NGK Spark Plug Co. Ltd., Aichi (Japan)

    1998-06-01

    Air to fuel ratio sensor is used for emission control system of three-way catalyst, and constitutes the important functional part of combustion control system. For further precise combustion control application, universal air to fuel ratio heated exhaust gas oxygen sensor (UEGO sensor) has been developed. This paper introduces heater control system for constant element temperature of UEGO sensor. By the heater wattage feedback control of sensing cell impedance, the change of sensor element temperature is decreased. 9 refs., 13 figs.

  15. Comparison and combination of NLPQL and MOGA algorithms for a marine medium-speed diesel engine optimisation

    International Nuclear Information System (INIS)

    Hu, Nao; Zhou, Peilin; Yang, Jianguo

    2017-01-01

    Highlights: • NLPQL algorithm is not effective when used for seven engine parameters optimisation. • MOGA algorithm is time consuming but offers broader and finer solutions. • A better design is offered by NLPQL algorithm when using a start point from MOGA. • SOI has the dominant and clearly opposite effects on NOx and SFOC. • Late injection, low swirl and large spray angle can lower NOx and soot simultaneously. - Abstract: Seven engine design parameters were investigated by use of NLPQL algorithm and MOGA separately and together. Detailed comparisons were made on NOx, soot, SFOC, and also on the design parameters. Results indicate that NLPQL algorithm failed to approach optimal designs while MOGA offered more and better feasible Pareto designs. Then, an optimal design obtained by MOGA which has the trade-off between NOx and soot was set as the starting point of NLPQL algorithm. In this situation, an even better design with lower NOx and soot was approached. Combustion processes of the optimal designs were also disclosed and compared in detail. Late injection and small swirl were reckoned to be the main reasons for reducing NOx. In the end, RSM contour maps were applied in order to gain a better understanding of the sensitivity of import parameters on NOx, soot and SFOC.

  16. Trend of supersonic aircraft engine. Choonsokukiyo engine no doko

    Energy Technology Data Exchange (ETDEWEB)

    Yashima, S [Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)

    1994-05-01

    The present paper explained the R and D trend of supersonic aircraft engine in Europe, USA and Japan. Taking the high speed flight resistance into consideration, the engine must be characterized by its high exhaust gas speed and high specific thrust (ratio of thrust to the airflow rate) to secure strong thrust by a low airflow rate. Therefore, the turbojet is appropriate. However to reduce the fuel consumption during the cruising flight, the turbofan is normally used with a low by-pass ratio of 0.2 to 0.9. The thrust-to-weight ratio (thrust per unit weight) of low by-pass ratio turbofan engine equipped with afterburner is 7 to 8 in case of stronger thrust than 70kN. Its target value of development is 10. The specific thrust which is a performance parameter of engine exceeds 120s for the fighter engine and is about 30s for the passenger plane engine. The turbine inlet temperature is 2073K at the stage of element research. The overall pressure ratio ranges from 25 to 30. The reheating turbofan engine experimentally built for the research in Japan is 34kN in thrust and 7 in thrust-to-weight ratio. 8 refs., 9 figs.

  17. Engine Modelling for Control Applications

    DEFF Research Database (Denmark)

    Hendricks, Elbert

    1997-01-01

    In earlier work published by the author and co-authors, a dynamic engine model called a Mean Value Engine Model (MVEM) was developed. This model is physically based and is intended mainly for control applications. In its newer form, it is easy to fit to many different engines and requires little...... engine data for this purpose. It is especially well suited to embedded model applications in engine controllers, such as nonlinear observer based air/fuel ratio and advanced idle speed control. After a brief review of this model, it will be compared with other similar models which can be found...

  18. Effect of yield to tensile (Y/T) ratio on the structural integrity of offshore pipeline: advanced engineering assessment using limit state design approach

    Energy Technology Data Exchange (ETDEWEB)

    Malatesta, G; Mannucci, G; Demofonti, G [Centro Sviluppo Materiali S.p.A., Rome (Italy); Cumino, G [TenarisDalmine (Italy); Izquierdo, A; Tivelli, M [Tenaris Group (Mexico); Quintanilla, H [TENARIS Group (Mexico). TAMSA

    2005-07-01

    Nowadays specifications require strict Yield to Tensile ratio limitation, nevertheless a fully accepted engineering assessment of its influence on pipeline integrity is still lacking. Probabilistic analysis based on structural reliability approach (Limit State Design) aimed at quantifying the Y/T ratio influence on failure probabilities of offshore pipelines was made. In particular, Tenaris seamless pipe data were used as input for the probabilistic failure analysis. The LSD approach has been applied to two actual deep water design cases that have been on purpose selected, and the most relevant failure modes have been considered. Main result of the work is that the quantitative effect of the Y/T ratio on failure probabilities of a deep water pipeline resulted not so big as expected; it has a minor effect, especially when failure modes are governed by Y only. (author)

  19. Base Flow and Heat Transfer Characteristics of a Four-Nozzle Clustered Rocket Engine: Effect of Nozzle Pressure Ratio

    Science.gov (United States)

    Nallasamy, R.; Kandula, M.; Duncil, L.; Schallhorn, P.

    2010-01-01

    The base pressure and heating characteristics of a four-nozzle clustered rocket configuration is studied numerically with the aid of OVERFLOW Navier-Stokes code. A pressure ratio (chamber pressure to freestream static pressure) range of 990 to 5,920 and a freestream Mach number range of 2.5 to 3.5 are studied. The qualitative trends of decreasing base pressure with increasing pressure ratio and increasing base heat flux with increasing pressure ratio are correctly predicted. However, the predictions for base pressure and base heat flux show deviations from the wind tunnel data. The differences in absolute values between the computation and the data are attributed to factors such as perfect gas (thermally and calorically perfect) assumption, turbulence model inaccuracies in the simulation, and lack of grid adaptation.

  20. High-Speed Computation of the Kleene Star in Max-Plus Algebraic System Using a Cell Broadband Engine

    Science.gov (United States)

    Goto, Hiroyuki

    This research addresses a high-speed computation method for the Kleene star of the weighted adjacency matrix in a max-plus algebraic system. We focus on systems whose precedence constraints are represented by a directed acyclic graph and implement it on a Cell Broadband Engine™ (CBE) processor. Since the resulting matrix gives the longest travel times between two adjacent nodes, it is often utilized in scheduling problem solvers for a class of discrete event systems. This research, in particular, attempts to achieve a speedup by using two approaches: parallelization and SIMDization (Single Instruction, Multiple Data), both of which can be accomplished by a CBE processor. The former refers to a parallel computation using multiple cores, while the latter is a method whereby multiple elements are computed by a single instruction. Using the implementation on a Sony PlayStation 3™ equipped with a CBE processor, we found that the SIMDization is effective regardless of the system's size and the number of processor cores used. We also found that the scalability of using multiple cores is remarkable especially for systems with a large number of nodes. In a numerical experiment where the number of nodes is 2000, we achieved a speedup of 20 times compared with the method without the above techniques.

  1. Effect of water injection and off scheduling of variable inlet guide vanes, gas generator speed and power turbine nozzle angle on the performance of an automotive gas turbine engine

    Science.gov (United States)

    Warren, E. L.

    1980-01-01

    The Chrysler/ERDA baseline automotive gas turbine engine was used to experimentally determine the power augmentation and emissions reductions achieved by the effect of variable compressor and power engine geometry, water injection downstream of the compressor, and increases in gas generator speed. Results were dependent on the mode of variable geometry utilization. Over 20 percent increase in power was accompanied by over 5 percent reduction in SFC. A fuel economy improvement of at least 6 percent was estimated for a vehicle with a 75 kW (100 hp) engine which could be augmented to 89 kW (120 hp) relative to an 89 Kw (120 hp) unaugmented engine.

  2. Study of ignition in a high compression ratio SI (spark ignition) methanol engine using LES (large eddy simulation) with detailed chemical kinetics

    International Nuclear Information System (INIS)

    Zhen, Xudong; Wang, Yang

    2013-01-01

    Methanol has been recently used as an alternative to conventional fuels for internal combustion engines in order to satisfy some environmental and economical concerns. In this paper, the ignition in a high compression ratio SI (spark ignition) methanol engine was studied by using LES (large eddy simulation) with detailed chemical kinetics. A 21-species, 84-reaction methanol mechanism was adopted to simulate the auto-ignition process of the methanol/air mixture. The MIT (minimum ignition temperature) and MIE (minimum ignition energy) are two important properties for designing safety standards and understanding the ignition process of combustible mixtures. The effects of the flame kernel size, flame kernel temperature and equivalence ratio were also examined on MIT, MIE and IDP (ignition delay period). The methanol mechanism was validated by experimental test. The simulated results showed that the flame kernel size, temperature and energy dramatically affected the values of the MIT, MIE and IDP for a methanol/air mixture, the value of the ignition delay period was not only related to the flame kernel energy, but also to the flame kernel temperature. - Highlights: • We used LES (large eddy simulation) coupled with detailed chemical kinetics to simulate methanol ignition. • The flame kernel size and temperature affected the minimum ignition temperature. • The flame kernel temperature and energy affected the ignition delay period. • The equivalence ratio of methanol–air mixture affected the ignition delay period

  3. Comparative study of engineering properties of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7

    Science.gov (United States)

    Tiecheng, Yan; Xingyuan, Zhang; Hongping, Yang

    2018-03-01

    This study describes an analytical comparison of the engineering characteristics of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7 using density measurements, results of indoor consolidation tests, and direct shear tests to examine the strength and deformation characteristics. It investigates the engineering performance of collapsible loess treated with waste tire particles and lime. The results indicate that (1) the shear strength of the two-lime waste tire particle soils increases continuously with soil age; and (2) the two-lime waste tire particle soils are light-weight, strong, and low-deformation soils, and can be applied primarily to improve the foundation soil conditions in areas with collapsible loess soils. This could address the problem of used tire disposal, while providing a new method to consider and manage collapsible loess soils.

  4. Speed Variance and Its Influence on Accidents.

    Science.gov (United States)

    Garber, Nicholas J.; Gadirau, Ravi

    A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…

  5. Systematic in vitro nanotoxicity study on anodic alumina nanotubes with engineered aspect ratio: understanding nanotoxicity by a nanomaterial model.

    Science.gov (United States)

    Wang, Ye; Kaur, Gagandeep; Zysk, Aneta; Liapis, Vasilios; Hay, Shelley; Santos, Abel; Losic, Dusan; Evdokiou, Andreas

    2015-04-01

    Here, we report a detailed and systematic approach for studying the in vitro nanotoxicity study of high aspect ratio (HAR) nanomaterials using anodic alumina nanotubes (AANTs) as a nanomaterial model. AANTs with bio-inert properties and tailored aspect ratios ranging from 7.8 to 63.3 were synthesized by an electrochemical pulse anodization process. Cytotoxicity studies were conducted with RAW 264.7 mouse macrophage cells and MDA-MB 231-TXSA human breast cancer cells through several toxicity parameters, including cell viability and morphology, pro-inflammatory response, mitochondrial depolarization, lysosomal membrane permeabilization (LMP), induction of autophagy and endoplasmic reticulum (ER) stress. The resulting toxicity patterns were cell-type dependent and strongly related with AANTs dose, length of time, and importantly the AR of AANTs. Long AANTs triggered enhanced cell death, morphological changes, tumor necrosis factor α (TNF-α) release, LMP and ER stress than short AANTs. The toxic AR window of AANTs was determined to be 7.8, which is shorter than that of other previously reported HAR nanomaterials. This toxic AR window provides a promising opportunity to control the nanotoxicity of HAR nanomaterials for their advanced drug delivery application. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. The Miller cycle effects on improvement of fuel economy in a highly boosted, high compression ratio, direct-injection gasoline engine: EIVC vs. LIVC

    International Nuclear Information System (INIS)

    Li, Tie; Gao, Yi; Wang, Jiasheng; Chen, Ziqian

    2014-01-01

    Highlights: • At high load, LIVC is superior over EIVC in improving fuel economy. • The improvement with LIVC is due to advanced combustion phasing and increased pumping work. • At low load, EIVC is better than LIVC in improving fuel economy. • Pumping loss with EIVC is smaller than with LIVC at low load. • But heat release rate with EIVC is slower than with LIVC. - Abstract: A combination of downsizing, highly boosting and direct injection (DI) is an effective way to improve fuel economy of gasoline engines without the penalties of reduced torque or power output. At high loads, however, knock problem becomes severer when increasing the intake boosting. As a compromise, geometric compression ratio (CR) is usually reduced to mitigate knock, and the improvement of fuel economy is discounted. Application of Miller cycle, which can be realized by either early or late intake valve closing (EIVC or LIVC), has the potential to reduce the effective CR and suppress knock. In this paper, the effects of EIVC and LIVC on the fuel economy of a boosted DI gasoline production engine reformed with a geometric CR of 12.0 are experimentally compared at low and high loads. Compared to the original production engine with CR 9.3, at the high load operation, the brake specific fuel consumption (BSFC) is improved by 4.7% with CR12.0 and LIVC, while the effect of EIVC on improving BSFC is negligibly small. At the low load operation, combined with CR12.0, LIVC and EIVC improve the fuel economy by 6.8% and 7.4%, respectively, compared to the production engine. The mechanism behind the effects of LIVC and EIVC on improving the fuel economy is discussed. These results will be a valuable reference for engine designers and researchers

  7. Adaptive Control Using Fully Online Sequential-Extreme Learning Machine and a Case Study on Engine Air-Fuel Ratio Regulation

    Directory of Open Access Journals (Sweden)

    Pak Kin Wong

    2014-01-01

    Full Text Available Most adaptive neural control schemes are based on stochastic gradient-descent backpropagation (SGBP, which suffers from local minima problem. Although the recently proposed regularized online sequential-extreme learning machine (ReOS-ELM can overcome this issue, it requires a batch of representative initial training data to construct a base model before online learning. The initial data is usually difficult to collect in adaptive control applications. Therefore, this paper proposes an improved version of ReOS-ELM, entitled fully online sequential-extreme learning machine (FOS-ELM. While retaining the advantages of ReOS-ELM, FOS-ELM discards the initial training phase, and hence becomes suitable for adaptive control applications. To demonstrate its effectiveness, FOS-ELM was applied to the adaptive control of engine air-fuel ratio based on a simulated engine model. Besides, controller parameters were also analyzed, in which it is found that large hidden node number with small regularization parameter leads to the best performance. A comparison among FOS-ELM and SGBP was also conducted. The result indicates that FOS-ELM achieves better tracking and convergence performance than SGBP, since FOS-ELM tends to learn the unknown engine model globally whereas SGBP tends to “forget” what it has learnt. This implies that FOS-ELM is more preferable for adaptive control applications.

  8. Production of syngas and oil at biomass refinery and their application in low speed two stroke engines for combined cycle electric energy generation

    Energy Technology Data Exchange (ETDEWEB)

    Pinatti, Daltro Garcia [Universidade do Sul de Santa Catarina (UNISUL), Tubarao, SC (Brazil)], E-mail: pinatti@demar.eel.usp.br; Oliveira, Isaias de; Ferreira, Joao Carlos; Romao, Erica Leonor [RM Materiais Refratarios Ltd., Lorena, SP (Brazil)], Emails: isaias@rm-gpc.com.br, joaocarlos@rm-gpc.com.br, ericaromao@rm-gpc.com.br; Conte, Rosa Ana [University of Sao Paulo (DEMAR/EEL/USP), SP (Brazil). Lorena School of Engineering. Dept. of Materials Engineering], E-mail: rosaconte@demar.eel.usp.br

    2009-07-01

    Low speed two stroke engines burn fuels of medium quality with high efficiency (47%) and allows a flexible use of oil (> 8% of total power) and syngas (< 92%, low heating value-LHV>11.2MJ/m{sup 3}). Biomass refinery (BR) generates oil from sludge and oleaginous biomass by low temperature conversion and syngas from lignocellulosic biomass treated by diluted acidic prehydrolysis. BR has low investment cost (US$1,500.00/kW) compared with hydroelectric plants (US$2,500.00/kW) and both generate electric energy with sales price below US$75.00/MWh. It allows distributed generation from 30 MW up to 170 MW or centralized power of 1 GW with six motor generator sets. BR matrix, mass and energy balance, fuels compositions, modulations and scope of supply will be presented. Besides electric energy BR can be tailored to supply other products such as ethanol, H{sub 2} for fuel cells, biodiesel, fertilizer recycling, char and simultaneously maximizes the production of animal protein. (author)

  9. Influence of fuel type, dilution and equivalence ratio on the emission reduction from the auto-ignition in an Homogeneous Charge Compression Ignition engine

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 4 place Jussieu, 75252 Paris cedex 05 (France); Universite Libre de Bruxelles, TIPs - Fluid Physics, CP165/67, 50 Avenue F.D. Roosevelt, 1050 Brussels (Belgium); Cavadias, Simeon [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, Institut Jean Le Rond D' Alembert, 4 place Jussieu, 75252 Paris cedex 05 (France); Amouroux, Jacques [UPMC Universite Paris 06, ENSCP, 11 rue de Pierre et Marie Curie, 75005 Paris (France)

    2010-04-15

    One technology that seems to be promising for automobile pollution reduction is the Homogeneous Charge Compression Ignition (HCCI). This technology still faces auto-ignition and emission-control problems. This paper focuses on the emission problem, since it is incumbent to realize engines that pollute less. For this purpose, this paper presents results concerning the measurement of the emissions of CO, NO{sub x}, CO{sub 2}, O{sub 2} and hydrocarbons. HCCI conditions are used, with equivalence ratios between 0.26 and 0.54, inlet temperatures of 70 C and 120 C and compression ratios of 10.2 and 13.5, with different fuel types: gasoline, gasoline surrogate, diesel, diesel surrogate and mixtures of n-heptane/toluene. The effect of dilution is considered for gasoline, while the effect of the equivalence ratio is considered for all the fuels. No significant amount of NO{sub x} has been measured. It appeared that the CO, O{sub 2} and hydrocarbon emissions were reduced by decreasing the toluene content of the fuel and by decreasing the dilution. The opposite holds for CO{sub 2}. The reduction of the hydrocarbon emission appears to compete with the reduction of the CO{sub 2} emission. Diesel seemed to produce less CO and hydrocarbons than gasoline when auto-ignited. An example of emission reduction control is presented in this paper. (author)

  10. Impact of branched structures on cycloalkane ignition in a motored engine: Detailed product and conformational analyses

    KAUST Repository

    Kang, Dongil; Lilik, Gregory K.; Dillstrom, Vernon Tyler; Agudelo, John Ramiro; Lapuerta, Magí n; Al-Qurashi, Khalid; Boehman, André Louis

    2015-01-01

    , equivalence ratio of 0.5 and engine speed of 600. rpm. The engine compression ratio (CR) was gradually increased in a stepwise manner until autoignition occurred. It was found that ECH exhibited a significantly higher oxidation reactivity compared to its two

  11. Separated core turbofan engine; Core bunrigata turbofan engine

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y; Endo, M; Matsuda, Y; Sugiyama, N; Sugahara, N; Yamamoto, K [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report outlines the separated core turbofan engine. This engine is featured by parallel separated arrangement of a fan and core engine which are integrated into one unit in the conventional turbofan engine. In general, cruising efficiency improvement and noise reduction are achieved by low fan pressure ratio and low exhaust speed due to high bypass ratio, however, it causes various problems such as large fan and nacelle weight due to large air flow rate of a fan, and shift of an operating point affected by flight speed. The parallel separated arrangement is thus adopted. The stable operation of a fan and core engine is easily retained by independently operating air inlet unaffected by fan. The large degree of freedom of combustion control is also obtained by independent combustor. Fast response, simple structure and optimum aerodynamic design are easily achieved. This arrangement is also featured by flexibility of development and easy maintenance, and by various merits superior to conventional turbofan engines. It has no technological problems difficult to be overcome, and is also suitable for high-speed VTOL transport aircraft. 4 refs., 5 figs.

  12. Discriminación de cantidad: efecto de la razón numérica sobre velocidad y precisión / Quantity discrimination: effect of number ratio over speed and accuracy

    Directory of Open Access Journals (Sweden)

    Jesica Formoso

    2016-06-01

    Full Text Available RESUMEN: La habilidad de estimar y discriminar cantidades es de aparición temprana en el desarrollo y previa a la adquisición de un sistema numérico simbólico. El rendimiento en tareas de discriminación está modulado por la razón numérica que diferencia los conjuntos, de forma tal que razones más pequeñas resultan en comparaciones más lentas y menos efectivas. El objetivo del presente trabajo es analizar la precisión y velocidad con que niños de 4 y 6 años discriminan entre dos cantidades en función de la razón numérica que las diferencia. Método: se administró una tarea de discriminación no simbólica de cantidades (ad hoc a 60 niños de 4 y 6 años de edad de la Ciudad Autónoma de Buenos Aires, Argentina. Se realizó un ANOVA de diseño mixto para analizar la cantidad de aciertos y los tiempos de reacción (TR en función de la edad y la razón numérica que diferencia los conjuntos. Se utilizó la prueba de contraste de Bonferroni para detectar las diferencias en aciertos y TR entre cada razón. Resultados: (a Los niños de 6 años mostraron TR más pequeños y mayor cantidad de aciertos que los niños de 4 años. Esto sugiere que la discriminación de cantidades atraviesa un proceso de desarrollo evolutivo. (b Cuanto mayor fue la razón numérica en la diferenciación de los conjuntos, más efectiva fue la discriminación. Esto sugiere que la razón modula el rendimiento, independientemente de la edad del sujeto. ABSTRACT: The ability to estimate and discriminate quantities is of early onset in the development and prior to the acquisition of a symbolic numerical system. The performance on tasks of discrimination is modulated by the number ratio that differentiates the sets, so that smaller reasons result in slower and less effective comparisons. The objective of the present study is to analyze the precision and speed by which 4 and 6 year old children discriminate between two quantities based on the number ratio that

  13. Characterization of Lean Misfire Limits of Mixture Alternative Gaseous Fuels Used for Spark Ignition Engines

    Directory of Open Access Journals (Sweden)

    Miqdam Tariq Chaichan

    2012-03-01

    Full Text Available Increasing on gaseous fuels as clean, economical and abundant fuels encourages the search for optimum conditions of gas-fueled internal combustion engines. This paper presents the experimental results on the lean operational limits of Recardo E6 engine using gasoline, LPG, NG and hydrogen as fuels. The first appearance of almost motoring cycle was used to define the engine lean limit after the fuel flow was reduced gradually. The effects of compression ratio, engine speed and spark timing on the engine operational limits are presented and discussed in detailed. Increasing compression ratio (CR extend the lean limits, this appears obviously with hydrogen, which has a wide range of equivalence ratios, while for hydrocarbon fuel octane number affect gasoline, so it can' t work above CR=9:1, and for LPG it reaches CR=12:1, NG reaches CR=15:1 at lean limit operation. Movement from low speeds to medium speeds extended lean misfire limits, while moving from medium to high speeds contracted the lean misfiring limits. NOx, CO and UBHC concentrations increased with CR increase for all fuels, while CO2 concentrations reduced with this increment. NOx concentration increased for medium speeds and reduced for high speeds, but the resulted concentrations were inconcedrable for these lean limits. CO and CO2 increased with engine speed increase, while UBHC reduced with this increment. The hydrogen engine runs with zero CO, CO2 and UNHC concentrations, and altra low levels of NOx concentrations at studied lean misfire limits

  14. Study of blade aspect ratio on a compressor front stage aerodynamic and mechanical design report

    Science.gov (United States)

    Burger, G. D.; Lee, D.; Snow, D. W.

    1979-01-01

    A single stage compressor was designed with the intent of demonstrating that, for a tip speed and hub-tip ratio typical of an advanced core compressor front stage, the use of low aspect ratio can permit high levels of blade loading to be achieved at an acceptable level of efficiency. The design pressure ratio is 1.8 at an adiabatic efficiency of 88.5 percent. Both rotor and stator have multiple-circular-arc airfoil sections. Variable IGV and stator vanes permit low speed matching adjustments. The design incorporates an inlet duct representative of an engine transition duct between fan and high pressure compressor.

  15. Factors of airplane engine performance

    Science.gov (United States)

    Gage, Victor R

    1921-01-01

    This report is based upon an analysis of a large number of airplane-engine tests. It contains the results of a search for fundamental relations between many variables of engine operation. The data used came from over 100 groups of tests made upon several engines, primarily for military information. The types of engines were the Liberty 12 and three models of the Hispano-Suiza. The tests were made in the altitude chamber, where conditions simulated altitudes up to about 30,000 feet, with engine speeds ranging from 1,200 to 2,200 r.p.m. The compression ratios of the different engines ranged from under 5 to over 8 to 1. The data taken on the tests were exceptionally complete, including variations of pressure and temperature, besides the brake and friction torques, rates of fuel and air consumption, the jacket and exhaust heat losses.

  16. Simultaneous high-speed gas property measurements at the exhaust gas recirculation cooler exit and at the turbocharger inlet of a multicylinder diesel engine using diode-laser-absorption spectroscopy.

    Science.gov (United States)

    Jatana, Gurneesh S; Magee, Mark; Fain, David; Naik, Sameer V; Shaver, Gregory M; Lucht, Robert P

    2015-02-10

    A diode-laser-absorption-spectroscopy-based sensor system was used to perform high-speed (100 Hz to 5 kHz) measurements of gas properties (temperature, pressure, and H(2)O vapor concentration) at the turbocharger inlet and at the exhaust gas recirculation (EGR) cooler exit of a diesel engine. An earlier version of this system was previously used for high-speed measurements of gas temperature and H(2)O vapor concentration in the intake manifold of the diesel engine. A 1387.2 N m tunable distributed feedback diode laser was used to scan across multiple H(2)O absorption transitions, and the direct absorption signal was recorded using a high-speed data acquisition system. Compact optical connectors were designed to conduct simultaneous measurements in the intake manifold, the EGR cooler exit, and the turbocharger inlet of the engine. For measurements at the turbocharger inlet, these custom optical connectors survived gas temperatures as high as 800 K using a simple and passive arrangement in which the temperature-sensitive components were protected from high temperatures using ceramic insulators. This arrangement reduced system cost and complexity by eliminating the need for any active water or oil cooling. Diode-laser measurements performed during steady-state engine operation were within 5% of the thermocouple and pressure sensor measurements, and within 10% of the H(2)O concentration values derived from the CO(2) gas analyzer measurements. Measurements were also performed in the engine during transient events. In one such transient event, where a step change in fueling was introduced, the diode-laser sensor was able to capture the 30 ms change in the gas properties; the thermocouple, on the other hand, required 7.4 s to accurately reflect the change in gas conditions, while the gas analyzer required nearly 600 ms. To the best of our knowledge, this is the first implementation of such a simple and passive arrangement of high-temperature optical connectors as well

  17. Speed control at low wind speeds for a variable speed fixed pitch wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Rosmin, N.; Watson, S.J.; Tompson, M. [Loughborough Univ., Loughborough, Leicestershire (United Kingdom)

    2010-03-09

    The maximum power regulation below rated wind speed is regulated by changing the rotor/generator speed at large frequency range in a fixed pitch, variable speed, stall-regulated wind turbine. In order to capture the power at a maximum value the power coefficient is kept at maximum peak point by maintaining the tip speed ratio at its optimum value. The wind industry is moving from stall regulated fixed speed wind turbines to newer improved innovative versions with better reliability. While a stall regulated fixed pitch wind turbine is among the most cost-effective wind turbine on the market, its problems include noise, severe vibrations, high thrust loads and low power efficiency. Therefore, in order to improve such drawbacks, the rotation of the generator speed is made flexible where the rotation can be controlled in variable speed. This paper discussed the development of a simulation model which represented the behaviour of a stall regulated variable speed wind turbine at low wind speed control region by using the closed loop scalar control with adjustable speed drive. The paper provided a description of each sub-model in the wind turbine system and described the scalar control of the induction machine. It was concluded that by using a constant voltage/frequency ratio of the generator's stator side control, the generator speed could be regulated and the generator torque could be controlled to ensure the power coefficient could be maintained close to its maximum value. 38 refs., 1 tab., 10 figs.

  18. COMBUSTION ANALYSIS OF A CNG DIRECT INJECTION SPARK IGNITION ENGINE

    Directory of Open Access Journals (Sweden)

    A. Rashid A. Aziz

    2010-12-01

    Full Text Available An experimental study was carried out on a dedicated compressed natural gas direct injection (CNG-DI engine with a compression ratio (CR of 14 and a central injection system. Several injection timing parameters from early injection timing (300 BTDC to partial direct injection (180 BTDC to full direct injection (120 BTDC were investigated. The 300 BTDC injection timing experiment was carried out to simulate the performance of a port injection engine and the result is used as a benchmark for engine performance. The full DI resulted in a 20% higher performance than the early injection timing for low engine speeds up to 2750 rpm. 180 BTDC injection timing shows the highest performance over an extensive range of engine speed because it has a similar volumetric efficiency to full DI. However, the earlier injection timing allowed for a better air–fuel mixing and gives superior performance for engine speeds above 4500 rpm. The engine performance could be explained by analysis of the heat release rate that shows that at low and intermediate engine speeds of 2000 and 3000, the full DI and partial DI resulted in the fastest heat release rate whereas at a high engine speed of 5000 rpm, the simulated port injection operation resulted in the fastest heat release rate.

  19. Speed mathematics

    CERN Document Server

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  20. Quiet engine program flight engine design study

    Science.gov (United States)

    Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

    1974-01-01

    The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

  1. The interactions between IC engine thermodynamics and knock

    International Nuclear Information System (INIS)

    Caton, Jerald A.

    2017-01-01

    Highlights: • Importance of engine thermodynamics regarding knock was quantified. • Effects of compression ratio, engine speed and EGR on knock was reported. • Retarding combustion to avoid knock resulted in decreases of efficiency. - Abstract: The development of high efficiency spark-ignition internal combustion engines is often constrained by the occurrence of knock. Knock may result in engine damage, lower performance, and lower efficiency. The options for preventing knock often involve lower compression ratios, lower boost, retarded spark timing, and other design choices that are detrimental to engine performance and efficiency. Since knock is largely a function of the thermodynamic state of the unburned zone, the occurrence of knock is expected to be a strong function of the engine thermodynamics. The purpose of the current work is to couple a simple knock model with a comprehensive engine cycle simulation to determine the interactions between the engine thermodynamics and knock. This work has explored the effects of engine parameters such as compression ratio (4–12), engine speed (500–2500 rpm), inlet pressure (50–100 kPa), exhaust gas recirculation (0–25%), combustion duration and heat transfer on knock. In each case, the occurrence of knock is connected to the cylinder pressures and the gas temperatures of the unburned zone. For example for a compression ratio of 12, to avoid knock the brake thermal efficiency decreased from 36.5% to 34% due to retarding the combustion.

  2. SOAC - State-of-the-Art Car Engineering Tests at Department of Transportation High Speed Ground Test Center : Volume 2. Performance Tests.

    Science.gov (United States)

    1975-01-01

    The six-volume report presents the technical methodology, data samples, and results of tests conducted on the SOAC on the Rail Transit Test Track at the High Speed Ground Test Center in Pueblo, Colorado during the period April to July 1973. The Test ...

  3. TRENDS IN THE DEVELOPMENT OF DETONATION ENGINES FOR HIGH-SPEED AEROSPACE AIRCRAFTS AND THE PROBLEM OF TRIPLE CONFIGURATIONS OF SHOCK WAVES. Part II - Research of counterpropagating shock waves and triple shock wave configurations

    Directory of Open Access Journals (Sweden)

    P. V. Bulat

    2016-03-01

    Full Text Available The paper deals with current issues of the interference theory development of gas-dynamic discontinuities as applied to a problem of propulsion refinement for the air-spacecrafts, designed for hypersonic flight speeds. In the first part of the review we have presented the history of detonation study and different concepts of detonation engines, as well as air intakes designed for hypersonic flight speeds. The second part provides an overview of works on the interference theory development for gas-dynamic discontinuities. We report about classification of the gas-dynamic discontinuities, shock wave propagation, shock-wave structures and triple configurations of shock waves. We have shown that many of these processes are accompanied by a hysteresis phenomenon, there are areas of ambiguity; therefore, in the design of engines and air intakes optimal shock-wave structures should be provided and their sustainability should be ensured. Much attention has recently been given to the use of the air intakes in the shock-wave structures with the rereflection of shock waves and the interference of shock waves in the opposite directions. This review provides increased focus on it, contains references to landmark works, the last calculated and experimental results. Unfortunately, foreign surveys missed many landmark works of the Soviet and Russian researchers, as they were not published in English. At the same time, it was the Soviet school of gas dynamics that has formulated the interference theory of gas-dynamic discontinuities in its present form. To fill this gap is one of this review scopes. The review may be recommended for professionals, engineers and scientists working in the field of aerospace engineering.

  4. Golden Ratio

    Indian Academy of Sciences (India)

    Our attraction to another body increases if the body is symmetricaland in proportion. If a face or a structure is in proportion,we are more likely to notice it and find it beautiful.The universal ratio of beauty is the 'Golden Ratio', found inmany structures. This ratio comes from Fibonacci numbers.In this article, we explore this ...

  5. Golden Ratio

    Indian Academy of Sciences (India)

    Keywords. Fibonacci numbers, golden ratio, Sanskrit prosody, solar panel. Abstract. Our attraction to another body increases if the body is symmetricaland in proportion. If a face or a structure is in proportion,we are more likely to notice it and find it beautiful.The universal ratio of beauty is the 'Golden Ratio', found inmany ...

  6. Golden Ratio

    Indian Academy of Sciences (India)

    Our attraction to another body increases if the body is sym- metrical and in proportion. If a face or a structure is in pro- portion, we are more likely to notice it and find it beautiful. The universal ratio of beauty is the 'Golden Ratio', found in many structures. This ratio comes from Fibonacci numbers. In this article, we explore this ...

  7. Quiet High Speed Fan II (QHSF II): Final Report

    Science.gov (United States)

    Kontos, Karen; Weir, Don; Ross, Dave

    2012-01-01

    This report details the aerodynamic, mechanical, structural design and fabrication of a Honey Engines Quiet High Speed Fan II (lower hub/tip ratio and higher specific flow than the Baseline I fan). This fan/nacelle system incorporates features such as advanced forward sweep and an advanced integrated fan/fan exit guide vane design that provides for the following characteristics: (1) Reduced noise at supersonic tip speeds, in comparison to current state-of-the-art fan technology; (2) Improved aeroelastic stability within the anticipated operating envelope; and (3) Aerodynamic performance consistent with current state-of-the-art fan technology. This fan was fabricated by Honeywell and tested in the NASA Glenn 9- by 15-Ft Low Speed Wind Tunnel for aerodynamic, aeromechanical, and acoustic performance.

  8. Super Turbocharging the Direct Injection Diesel engine

    Science.gov (United States)

    Boretti, Albert

    2018-03-01

    The steady operation of a turbocharged diesel direct injection (TDI) engine featuring a variable speed ratio mechanism linking the turbocharger shaft to the crankshaft is modelled in the present study. Key parameters of the variable speed ratio mechanism are range of speed ratios, efficiency and inertia, in addition to the ability to control relative speed and flow of power. The device receives energy from, or delivers energy to, the crankshaft or the turbocharger. In addition to the pistons of the internal combustion engine (ICE), also the turbocharger thus contributes to the total mechanical power output of the engine. The energy supply from the crankshaft is mostly needed during sharp accelerations to avoid turbo-lag, and to boost torque at low speeds. At low speeds, the maximum torque is drastically improved, radically expanding the load range. Additionally, moving closer to the points of operation of a balanced turbocharger, it is also possible to improve both the efficiency η, defined as the ratio of the piston crankshaft power to the fuel flow power, and the total efficiency η*, defined as the ratio of piston crankshaft power augmented of the power from the turbocharger shaft to the fuel flow power, even if of a minimal extent. The energy supply to the crankshaft is possible mostly at high speeds and high loads, where otherwise the turbine could have been waste gated, and during decelerations. The use of the energy at the turbine otherwise waste gated translates in improvements of the total fuel conversion efficiency η* more than the efficiency η. Much smaller improvements are obtained for the maximum torque, yet again moving closer to the points of operation of a balanced turbocharger. Adopting a much larger turbocharger (target displacement x speed 30% larger than a conventional turbocharger), better torque outputs and fuel conversion efficiencies η* and η are possible at every speed vs. the engine with a smaller, balanced turbocharger. This result

  9. Design and Performance Analysis of a Biodiesel Engine Driven Refrigeration System for Vaccine Storage

    Directory of Open Access Journals (Sweden)

    K Kamsuk

    2013-06-01

    Full Text Available A compact, stand-alone, refrigeration module powered by a small biodiesel engine for vaccine storage in rural use was proposed. The engine was of single cylinder, four-stroke, directinjection with displacement of 0.296 cm3 and compression ratio of 20:1. The refrigeration system was modified from an automotive vapor compression system. The system performance was analytically investigated. From the simulation, it was found to have acceptable operation over a range of speeds and loads. Performance of the system in terms of fuel consumption and torque tended to decrease with an increase in engine speed. The modular system was able to operate at cooling loads above 4.6 kW, with proper speed ratio between the engine and the compressor. Overall, primary energy ratio of the refrigeration was found to be maximum at 0.54.

  10. Investigation the performance of 0-D and 3-d combustion simulation softwares for modelling HCCI engine with high air excess ratios

    Directory of Open Access Journals (Sweden)

    Gökhan Coşkun

    2017-10-01

    Full Text Available In this study, performance of zero and three dimensional simulations codes that used for simulate a homogenous charge compression ignition (HCCI engine fueled with Primary Reference Fuel PRF (85% iso-octane and 15% n-heptane were investigated. 0-D code, called as SRM Suite (Stochastic Reactor Model which can simulate engine combustion by using stochastic reactor model technique were used. Ansys-Fluent which can simulate computational fluid dynamics (CFD was used for 3-D engine combustion simulations. Simulations were evaluated for both commercial codes in terms of combustion, heat transfer and emissions in a HCCI engine. Chemical kinetic mechanisms which developed by Tsurushima including 33 species and 38 reactions for surrogate PRF fuel were used for combustion simulations. Analysis showed that both codes have advantages over each other.

  11. Sex ratios

    OpenAIRE

    West, Stuart A; Reece, S E; Sheldon, Ben C

    2002-01-01

    Sex ratio theory attempts to explain variation at all levels (species, population, individual, brood) in the proportion of offspring that are male (the sex ratio). In many cases this work has been extremely successful, providing qualitative and even quantitative explanations of sex ratio variation. However, this is not always the situation, and one of the greatest remaining problems is explaining broad taxonomic patterns. Specifically, why do different organisms show so ...

  12. Optimization design and performance analysis of a miniature stirling engine

    Science.gov (United States)

    You, Zhanping; Yang, Bo; Pan, Lisheng; Hao, Changsheng

    2017-10-01

    Under given operation conditions, a stirling engine of 2 kW is designed which takes hydrogen as working medium. Through establishment of adiabatic model, the ways are achieved about performance improving. The ways are raising the temperature of hot terminal, lowering the temperature of cold end, increasing the average cycle pressure, speeding up the speed, phase angle being 90°, stroke volume ratio approximating to 1 and increasing the performance of regenerator.

  13. Natural gas in a D. I. diesel engine. A comparison of two different ways. [Direct injection diesel enginer

    Energy Technology Data Exchange (ETDEWEB)

    Jun-ming, Qu; Sorenson, S.C.; Kofoed, E.

    1987-01-01

    A D.I. diesel engine was modified for natural gas operation with pilot injection and with spark ignition so that a comparative analysis of these two different ways of using natural gas could be made. The results of the experiments indicate that for a diesel engine, it is possible that the operating characteristics of a straight natural gas engine are comparable with those of a diesel/gas engine at the same compression ratio and speed. For a dual fuel engine with pilot injection the best diesel/gas ratio by energy content is approximately 20/80 at full load operation. For straight natural gas engine with spark ignition, quality governed natural gas operation has good efficiency but poor NOx emissions. This problem could be improved through throttle controlled operation. These two different ways of using natural gas are best suited to stationary engines.

  14. Performance and emissions of a modified small engine operated on producer gas

    International Nuclear Information System (INIS)

    Homdoung, N.; Tippayawong, N.; Dussadee, N.

    2015-01-01

    Highlights: • A small agricultural diesel engine was converted into a spark ignited engine. • The modified engine operated solely on producer gas at various loads and speeds. • It run successfully at high compression ratio, without knocking. • Improvement in efficiency and specific energy consumption at higher CR was evident. - Abstract: Existing agricultural biomass may be upgraded converted to a gaseous fuel via a downdraft gasifier for spark ignition engines. In this work, a 0.6 L, naturally aspirated single cylinder compression ignition engine was converted into a spark ignition engine and coupled to a 5 kW dynamometer. The conventional swirl combustion chamber was replaced by a cavity chamber. The effect of variable compression ratios between 9.7 and 17:1, and engine speeds between 1000 and 2000 rpm and loads between 20% and 100% of engine performance were investigated in terms of engine torque, power output, thermal efficiency, specific fuel consumption and emissions. It was found that the modified engine was able to operate well with producer gas at higher compression ratios than with gasoline. The brake thermal efficiency was lower than the original diesel engine at 11.3%. Maximum brake power was observed to be 3.17 kW, and the best BSFC of 0.74 kg/kWh was achieved. Maximum brake thermal efficiency of 23.9% was obtained. The smoke density of the engine was lower than the diesel engine, however, CO emission was higher with similar HC emission

  15. Performance and combustion characteristics of direct-injection stratified-charge rotary engines

    Science.gov (United States)

    Nguyen, Hung Lee

    1987-01-01

    Computer simulations of the direct-injection stratified-charge (DISC) Wankel engine have been used to calculate heat release rates and performance and efficiency characteristics of the 1007R engine. Engine pressure data have been used in a heat release analysis to study the effects of heat transfer, leakage, and crevice flows. Predicted engine performance data are compared with experimental test data over a range of engine speeds and loads. An examination of methods to improve the performance of the Wankel engine with faster combustion, reduced leakage, higher compression ratio, and turbocharging is presented.

  16. Trends in aircraft engines. Trends in aircraft gas turbines and subsonic engines

    Energy Technology Data Exchange (ETDEWEB)

    Murashima, Kanji

    1988-06-10

    While the emphasis of commercial, large aircraft engines is placed on low fuel consumption at high subsonic flight and the turbofan engines with high bypass ratio are dominating, high speed turboprop (ATP) of Mach 0.85 class with low fuel consumption are emerging. UHB with bypass ratio of 15 - 20 are planned with expection for application to intermediate size commercial planes. The pressure ratio is continuously rizing for improved cycle efficiency, reaching 35 - 40 in highest cases. Trends in design technique include: Use of computational aerodynamics and application of two-dimensional structural analysis and the digital simulation of engine characteristics. In the field of large, high bypass turbofan, serious competition is seen between GE and PNA at the thrust level of 5 - 60,000 pounds. Several engines for fighting planes have been approved in the type test and accepted as candidates for next generation of fighting planes including Japan. (15 figs, 36 refs)

  17. Exploiting deterministic maintenance opportunity windows created by conservative engineering design rules that result in free time locked into large high-speed coupled production lines with finite buffers

    Directory of Open Access Journals (Sweden)

    Durandt, Casper

    2016-08-01

    Full Text Available Conservative engineering design rules for large serial coupled production processes result in machines having locked-in free time (also called ‘critical downtime’ or ‘maintenance opportunity windows’, which cause idle time if not used. Operators are not able to assess a large production process holistically, and so may not be aware that they form the current bottleneck – or that they have free time available due to interruptions elsewhere. A real-time method is developed to accurately calculate and display free time in location and magnitude, and efficiency improvements are demonstrated in large-scale production runs.

  18. Experimental study of dual fuel engine performance using variable LPG composition and engine parameters

    International Nuclear Information System (INIS)

    Elnajjar, Emad; Selim, Mohamed Y.E.; Hamdan, Mohammad O.

    2013-01-01

    Highlights: • The effect of using variable LPG is studied. • Five fuels with propane to butane % volume ratio are: 100-70-55-25-0. • 100% Propane composition shows the highest noise levels with similar performance. • At 45° BTDC injection timing 55% Propane LPG the only fuel experience knocking. • LPG fuels gave similar engine performance, with differences in levels of noise. - Abstract: The present work investigates experimentally the effect of LPG fuel with different composition and engine parameters on the performance of a dual compression engine. Five different blends of LPG fuels are used with Propane to Butane volume ratio of 100:0, 70:30, 55:45, 25:75, and 0:100. A single cylinder, naturally aspirated, four strokes, indirectly injected, water cooled modified Ricardo E6 engine, is used in this study. The study is carried out by measuring the cylinder pressure, engine load, engine speed, crank angle, and the fuel’s flow rate. The engine performance under variable LPG fuel composition, engine load, pilot fuel injection timing, compression ratio, pilot fuel mass and engine speed, are estimated by comparing the following engine parameters: the cylinder maximum pressure, the indicated mean effective pressure, the maximum rate of pressure rise, and the thermal efficiency. The experimental data indicates that the engine parameters are playing a major role on the engine’s performance. Different LPG fuel composition did not show a major effect on the engine efficiency but directly impacted the levels of generated combustion noise

  19. Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

    Science.gov (United States)

    Hernandez, Wilmar

    2006-01-01

    Among the complete family of sensors for automotive safety, consumer and industrial application, speed sensors stand out as one of the most important. Actually, speed sensors have the diversity to be used in a broad range of applications. In today's automotive industry, such sensors are used in the antilock braking system, the traction control system and the electronic stability program. Also, typical applications are cam and crank shaft position/speed and wheel and turbo shaft speed measurement. In addition, they are used to control a variety of functions, including fuel injection, ignition timing in engines, and so on. However, some types of speed sensors cannot respond to very low speeds for different reasons. What is more, the main reason why such sensors are not good at detecting very low speeds is that they are more susceptible to noise when the speed of the target is low. In short, they suffer from noise and generally only work at medium to high speeds. This is one of the drawbacks of the inductive (magnetic reluctance) speed sensors and is the case under study. Furthermore, there are other speed sensors like the differential Hall Effect sensors that are relatively immune to interference and noise, but they cannot detect static fields. This limits their operations to speeds which give a switching frequency greater than a minimum operating frequency. In short, this research is focused on improving the performance of a variable reluctance speed sensor placed in a car under performance tests by using a recursive least-squares (RLS) lattice algorithm. Such an algorithm is situated in an adaptive noise canceller and carries out an optimal estimation of the relevant signal coming from the sensor, which is buried in a broad-band noise background where we have little knowledge of the noise characteristics. The experimental results are satisfactory and show a significant improvement in the signal-to-noise ratio at the system output.

  20. Study on a constant-tip-speed-ratio operation of wind power generation system. Effect of load control system on dynamic behavior; Furyoku hatsuden system no hensoku seigyo unten ni kansuru kenkyu. Fuka seigyokei ga system no rikigakuteki kyodo ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Wakui, T.; Yamaguchi, K. [Waseda University, Tokyo (Japan); Tanzawa, Y. [Nippon Institute of Technology, Saitama (Japan); Hashizume, T.; Ota, E. [Waseda University, Tokyo (Japan). School of Science and Engineering

    1998-06-01

    The effect that the set data of the load control system in a wind power generation system exerts on the dynamic behavior of a system was investigated. The wind power generation system consists of a hybrid wind turbine with combined Darrieus and Savonius rotors, load with a generator and battery in the center, and a controller. A constant-tip-speed ratio operation that holds the circumferential speed ratio in which the power coefficient is maximized irrespective of the change in wind velocity was used to extract and convert the wind energy more effectively. In a high-wind velocity area, the system is operated at a fixed speed, and the increase in rotation is suppressed to protect the wing strength. In a large system, the response characteristics are only slightly improved by the limited load operation range and influenced rotor inertial. Power cannot be fully extracted even if the control system is changed in setting, and the applicability to the wind situation remains low. During the actual operation, the adjustment value of the control system should be set so that the output operation is satisfactorily possible in the specified load operation range, that is, the change in the instantaneous value of an effective power coefficient indicates almost flat gain characteristics in frequency characteristics. 14 refs., 10 figs., 2 tabs.

  1. Thermal balance of a LPG fuelled, four stroke SI engine with water addition

    International Nuclear Information System (INIS)

    Ozcan, Hakan; Soeylemez, M.S.

    2006-01-01

    The effect of water injection on a spark ignition engine thermal balance and performance has been experimentally investigated. A four stroke, four cylinder conventional engine was used with LPG (liquid petroleum gas) as fuel. Different water to fuel ratios by mass were used with variable engine speed ranging from 1000 to 4500 rpm. The results showed that as the water injection level to the engine increased, the percentage of useful work increased, while the losses other than unaccounted losses decreased. Additionally, the specific fuel consumption decreases, while the engine thermal efficiency increases. The average increase in the brake thermal efficiency for a 0.5 water to fuel mass ratio is approximately 2.7% over the use of LPG alone for the engine speed range studied

  2. Miniaturization limitations of rotary internal combustion engines

    International Nuclear Information System (INIS)

    Wang, Wei; Zuo, Zhengxing; Liu, Jinxiang

    2016-01-01

    Highlights: • Developed a phenomenological model for rotary internal combustion engines. • Presented scaling laws for the performance of micro rotary engines. • Adiabatic walls can improve the cycle efficiency but result in higher charge leakage. • A lower compression ratio can increase the efficiency due to lower mass losses. • Presented possible minimum engine size of rotary internal combustion engines. - Abstract: With the rapid development of micro electro-mechanical devices, the demands for micro power generation systems have significantly increased in recent years. Traditional chemical batteries have energy densities much lower than hydrocarbon fuels, which makes internal-combustion-engine an attractive technological alternative to batteries. Micro rotary internal combustion engine has drawn great attractions due to its planar design, which is well-suited for fabrication in MEMS. In this paper, a phenomenological model considering heat transfer and mass leakage has been developed to investigate effects of engine speed, compression ratio, blow-by and heat transfer on the performance of micro rotary engine, which provide the guidelines for preliminary design of rotary engine. The lower possible miniaturization limits of rotary combustion engines are proposed.

  3. Post-Synapse Model Cell for Synaptic Glutamate Receptor (GluR-Based Biosensing: Strategy and Engineering to Maximize Ligand-Gated Ion-Flux Achieving High Signal-to-Noise Ratio

    Directory of Open Access Journals (Sweden)

    Tetsuya Haruyama

    2012-01-01

    Full Text Available Cell-based biosensing is a “smart” way to obtain efficacy-information on the effect of applied chemical on cellular biological cascade. We have proposed an engineered post-synapse model cell-based biosensors to investigate the effects of chemicals on ionotropic glutamate receptor (GluR, which is a focus of attention as a molecular target for clinical neural drug discovery. The engineered model cell has several advantages over native cells, including improved ease of handling and better reproducibility in the application of cell-based biosensors. However, in general, cell-based biosensors often have low signal-to-noise (S/N ratios due to the low level of cellular responses. In order to obtain a higher S/N ratio in model cells, we have attempted to design a tactic model cell with elevated cellular response. We have revealed that the increase GluR expression level is not directly connected to the amplification of cellular responses because the saturation of surface expression of GluR, leading to a limit on the total ion influx. Furthermore, coexpression of GluR with a voltage-gated potassium channel increased Ca2+ ion influx beyond levels obtained with saturating amounts of GluR alone. The construction of model cells based on strategy of amplifying ion flux per individual receptors can be used to perform smart cell-based biosensing with an improved S/N ratio.

  4. Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

    Science.gov (United States)

    Maki, Ralph L.

    1959-01-01

    Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

  5. Effects of Canola Oil Biodiesel Fuel Blends on Combustion, Performance, and Emissions Reduction in a Common Rail Diesel Engine

    Directory of Open Access Journals (Sweden)

    Sam Ki Yoon

    2014-12-01

    Full Text Available In this study, we investigated the effects of canola oil biodiesel (BD to improve combustion and exhaust emissions in a common rail direct injection (DI diesel engine using BD fuel blended with diesel. Experiments were conducted with BD blend amounts of 10%, 20%, and 30% on a volume basis under various engine speeds. As the BD blend ratio increased, the combustion pressure and indicated mean effective pressure (IMEP decreased slightly at the low engine speed of 1500 rpm, while they increased at the middle engine speed of 2500 rpm. The brake specific fuel consumption (BSFC increased at all engine speeds while the carbon monoxide (CO and particulate matter (PM emissions were considerably reduced. On the other hand, the nitrogen oxide (NOx emissions only increased slightly. When increasing the BD blend ratio at an engine speed of 2000 rpm with exhaust gas recirculation (EGR rates of 0%, 10%, 20%, and 30%, the combustion pressure and IMEP tended to decrease. The CO and PM emissions decreased in proportion to the BD blend ratio. Also, the NOx emissions decreased considerably as the EGR rate increased whereas the BD blend ratio only slightly influenced the NOx emissions.

  6. Peak power ratio generator

    Science.gov (United States)

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  7. Study of compressor systems for a gas-generator engine

    Science.gov (United States)

    Sather, Bernard I; Tauschek, Max J

    1950-01-01

    Various methods of providing compressor-capacity and pressure-ratio control in the gas-generator type of compound engine over a range of altitudes from sea level to 50,000 feet are presented. The analytical results indicate that the best method of control is that in which the first stage of compression is carried out in a variable-speed supercharger driven by a hydraulic slip coupling. The constant-speed second stage could be either a mixed-flow rotary compressor or a piston-type compressor. A variable-area turbine nozzle is shown to be unnecessary for cruising operation of the engine.

  8. Simulation and Empirical Studies of the Commercial SI Engine Performance and Its Emission Levels When Running on a CNG and Hydrogen Blend

    Directory of Open Access Journals (Sweden)

    Rafaa Saaidia

    2017-12-01

    Full Text Available This article is a report on a simulation based on Computational Fluid Dynamics (CFD and an empirical investigation of in-cylinder flow characteristics, In addition, it assesses the performance and emission levels of a commercial-spark ignited engine running on a CNG and Hydrogen blend in different ratios. The main objective was to determine the optimum hydrogen ratio that would yield the best brake torque and release the least polluting gases. The in-cylinder flow velocity and turbulence aspects were investigated during the intake stroke in order to analyze the intake flow behavior. To reach this goal, a 3D CFD code was adopted. For various engine speeds were investigated for gasoline, CNG and hydrogen and CNG blend (HCNG fueled engines via external mixtures. The variation of brake torque (BT, NOX and CO emissions. A series of tests were conducted on the engine within the speed range of 1000 to 5000 rpm. For this purpose, a commercial Hyundai Sonata S.I engine was modified to operate with a blend of CNG and Hydrogen in different ratios. The experiments attempted to determine the optimum allowable hydrogen ratio with CNG for normal engine operation. The engine performance and the emission levels were also analyzed. At the engine speed of 4200 rpm, the results revealed that beyond a ratio of 50% of the volume of hydrogen added to CNG a backfire phenomenon appeared. Below this ratio (0~40% of the hydrogen volume, the CNG and Hydrogen blend seemed to be beneficial for the engine performance and for curtailing the emission level. However, at low engine speeds, the NOX concentration increased simultaneously with hydrogen content. In contrast, at high engine speeds, the NOX concentration decreased to its lowest level compared to that reached with gasoline as a running fuel. The concentration levels of HC, CO2, and CO decreased with the increase of hydrogen percentage.

  9. Compound cycle engine for helicopter application

    Science.gov (United States)

    Castor, Jere G.

    1986-01-01

    The Compound Cycle Engine (CCE) is a highly turbocharged, power compounded, ultra-high power density, light-weight diesel engine. The turbomachinery is similar to a moderate pressure ratio, free power turbine engine and the diesel core is high speed and a low compression ratio. This engine is considered a potential candidate for future military light helicopter applications. This executive summary presents cycle thermodynamic (SFC) and engine weight analyses performed to establish general engine operating parameters and configuration. An extensive performance and weight analysis based on a typical two hour helicopter (+30 minute reserve) mission determined final conceptual engine design. With this mission, CCE performance was compared to that of a T-800 class gas turbine engine. The CCE had a 31% lower-fuel consumption and resulted in a 16% reduction in engine plus fuel and fuel tank weight. Design SFC of the CCE is 0.33 lb-HP-HR and installed wet weight is 0.43 lbs/HP. The major technology development areas required for the CCE are identified and briefly discussed.

  10. Low-speed tests of a high-aspect-ratio, supercritical-wing transport model equipped with a high-lift flap system in the Langley 4- by 7-meter and Ames 12-foot pressure tunnels

    Science.gov (United States)

    Morgan, H. L., Jr.; Kjelgaard, S. O.

    1983-01-01

    The Ames 12-Foot Pressure Tunnel was used to determine the effects of Reynolds number on the static longitudinal aerodynamic characteristics of an advanced, high-aspect-ratio, supercritical wing transport model equipped with a full span, leading edge slat and part span, double slotted, trailing edge flaps. The model had a wing span of 7.5 ft and was tested through a free stream Reynolds number range from 1.3 to 6.0 x 10 to 6th power per foot at a Mach number of 0.20. Prior to the Ames tests, an investigation was also conducted in the Langley 4 by 7 Meter Tunnel at a Reynolds number of 1.3 x 10 to 6th power per foot with the model mounted on an Ames strut support system and on the Langley sting support system to determine strut interference corrections. The data obtained from the Langley tests were also used to compare the aerodynamic charactertistics of the rather stiff, 7.5-ft-span steel wing model tested during this investigation and the larger, and rather flexible, 12-ft-span aluminum-wing model tested during a previous investigation. During the tests in both the Langley and Ames tunnels, the model was tested with six basic wing configurations: (1) cruise; (2) climb (slats only extended); (3) 15 deg take-off flaps; (4) 30 deg take-off flaps; (5) 45 deg landing flaps; and (6) 60 deg landing flaps.

  11. Biogas engine performance estimation using ANN

    Directory of Open Access Journals (Sweden)

    Yusuf Kurtgoz

    2017-12-01

    Full Text Available Artificial neural network (ANN method was used to estimate the thermal efficiency (TE, brake specific fuel consumption (BSFC and volumetric efficiency (VE values of a biogas engine with spark ignition at different methane (CH4 ratios and engine load values. For this purpose, the biogas used in the biogas engine was produced by the anaerobic fermentation method from bovine manure and different CH4 contents (51%, 57%, 87% were obtained by purification of CO2 and H2S. The data used in the ANN models were obtained experimentally from a 4-stroke four-cylinder, spark ignition engine, at constant speed for different load and CH4 ratios. Using some of the obtained experimental data, ANN models were developed, and the rest was used to test the developed models. In the ANN models, the CH4 ratio of the fuel, engine load, inlet air temperature (Tin, air fuel ratio and the maximum cylinder pressure are chosen as the input parameters. TE, BSFC and VE are used as the output parameters. Root mean square error (RMSE, mean absolute percentage error (MAPE and correlation coefficient (R performance indicators are used to compare measured and predicted values. It has been shown that ANN models give good results in spark ignition biogas engines with high correlation and low error rates for TE, BSFC and VE values.

  12. Numerical investigation of ethanol fuelled HCCI engine using stochastic reactor model. Part 2: Parametric study of performance and emissions characteristics using new reduced ethanol oxidation mechanism

    International Nuclear Information System (INIS)

    Maurya, Rakesh Kumar; Akhil, Nekkanti

    2016-01-01

    Highlights: • Newly developed reduced ethanol mechanism (47 species and 272 reactions) used. • Engine maps over wide range are developed for performance and emissions parameters. • HCCI operating range increases with compression ratio & decreases with engine speed. • Maximum combustion efficiency up to 99% and thermal efficiency up to 50% is achieved. • Maximum N_2O emission found up to 2.7 ppm and lower load have higher N_2O emission. - Abstract: Ethanol fuelled homogenous charge compression ignition engine offers a better alternative to tackle the problems of achieving higher engine efficiency and lower emissions using renewable fuel. Present study computationally investigates the HCCI operating range of ethanol at different compression ratios by varying inlet air temperature and engine speed using stochastic reactor model. A newly developed reduced ethanol oxidation mechanism with NO_x having 47 species and 272 reactions is used for simulation. HCCI operating range for compression ratios 17, 19 and 21 are investigated and found to be increasing with compression ratio. Simulations are conducted for engine speeds ranging from 1000 to 3000 rpm at different intake temperatures (range 365–465 K). Parametric study of combustion and emission characteristics is conducted and engine maps are developed at most efficient inlet temperatures. HCCI operating range is defined using combustion efficiency (>85%) and maximum pressure rise rate (<5 MPa/ms). In HCCI operating range, higher efficiency is found at higher engine loads and lower engine speeds. Emission characteristics of species (NO_x, N_2O, CO, CH_4, C_2H_4, C_2H_6, CH_3CHO, and HCHO) found in significant amount is also analysed for ethanol fulled HCCI engine. Emission maps for different species are presented and discussed for wide range of speed and load conditions. Some of unregulated species such as aldehydes are emitted in significantly higher quantities from ethanol fuelled HCCI engine at higher load

  13. Influence of Compression Ratio on High Load Performance and Knock Behavior for Gasoline Port-Fuel Injection, Natural Gas Direct Injection and Blended Operation in a Spark Ignition Engine

    Energy Technology Data Exchange (ETDEWEB)

    Pamminger, Michael; Sevik, James; Scarcelli, Riccardo; Wallner, Thomas; Hall, Carrie

    2017-03-28

    Natural Gas (NG) is an alternative fuel which has attracted a lot of attention recently, in particular in the US due to shale gas availability. The higher hydrogen-to-carbon (H/C) ratio, compared to gasoline, allows for decreasing carbon dioxide emissions throughout the entire engine map. Furthermore, the high knock resistance of NG allows increasing the efficiency at high engine loads compared to fuels with lower knock resistance. NG direct injection (DI) allows for fuel to be added after intake valve closing (IVC) resulting in an increase in power density compared to an injection before IVC. Steady-state engine tests were performed on a single-cylinder research engine equipped with gasoline (E10) port-fuel injection (PFI) and NG DI to allow for in-cylinder blending of both fuels. Knock investigations were performed at two discrete compression ratios (CR), 10.5 and 12.5. Operating conditions span mid-load, wide-open-throttle and boosted conditions, depending on the knock response of the fuel blend. Blended operation was performed using E10 gasoline and NG. An additional gasoline type fuel (E85) with higher knock resistance than E10 was used as a high-octane reference fuel, since the octane rating of E10-NG fuel blends is unknown. Spark timing was varied at different loads under stoichiometric conditions in order to study the knock response as well as the effects on performance and efficiency. As anticipated, results suggest that the knock resistance can be increased significantly by increasing the NG amount. Comparing the engine operation with the least knock resistant fuel, E10 PFI, and the fuel blend with the highest knock resistance, 75% NG DI, shows an increase in indicated mean effective pressure of about 9 bar at CR 12.5. The usage of reference fuels with known knock characteristics allowed an assessment of knock characteristic of intermediate E10-NG blend levels. Mathematical correlations were developed allowing characterizing the occurrence of knocking

  14. Urban traffic pollution reduction for sedan cars using petrol engines by hydro-oxide gas inclusion.

    Science.gov (United States)

    Al-Rousan, Ammar A; Alkheder, Sharaf; Musmar, Sa'ed A

    2015-12-01

    Petrol cars, in particular nonhybrid cars, contribute significantly to the pollution problem as compared with other types of cars. The originality of this article falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/hr). Results indicated that through using hydro-oxy gas, a noticeable reduction in pollution was recorded. Oxygen (O2) percentage has increased by about 2.5%, and nitric oxide (NO) level has been reduced by about 500 ppm. Carbon monoxide (CO) has decreased by about 2.2%, and also CO2 has decreased by 2.1%. It's worth mentioning that for hybrid system in cars at speeds between 10 and 50 km/hr, the emission percentage change is zero. However, hybrid cars are less abundant than petrol cars. The originality of this paper falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/h).

  15. Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm

    Directory of Open Access Journals (Sweden)

    Wilmar Hernandez

    2006-02-01

    Full Text Available Among the complete family of sensors for automotive safety, consumer andindustrial application, speed sensors stand out as one of the most important. Actually, speedsensors have the diversity to be used in a broad range of applications. In today’s automotiveindustry, such sensors are used in the antilock braking system, the traction control systemand the electronic stability program. Also, typical applications are cam and crank shaftposition/speed and wheel and turbo shaft speed measurement. In addition, they are used tocontrol a variety of functions, including fuel injection, ignition timing in engines, and so on.However, some types of speed sensors cannot respond to very low speeds for differentreasons. What is more, the main reason why such sensors are not good at detecting very lowspeeds is that they are more susceptible to noise when the speed of the target is low. In short,they suffer from noise and generally only work at medium to high speeds. This is one of thedrawbacks of the inductive (magnetic reluctance speed sensors and is the case under study.Furthermore, there are other speed sensors like the differential Hall Effect sensors that arerelatively immune to interference and noise, but they cannot detect static fields. This limitstheir operations to speeds which give a switching frequency greater than a minimumoperating frequency. In short, this research is focused on improving the performance of avariable reluctance speed sensor placed in a car under performance tests by using arecursive least-squares (RLS lattice algorithm. Such an algorithm is situated in an adaptivenoise canceller and carries out an optimal estimation of the relevant signal coming from thesensor, which is buried in a broad-band noise background where we have little knowledgeof the noise characteristics. The experimental results are satisfactory and show a significantimprovement in the signal-to-noise ratio at the system output.

  16. Fonctionnement transitoire et controle de la richesse des moteurs à allumage commandé à injection multipoint Transient Operation and Air-Fuel Ratio Control of Spark-Ignition Port-Injected Engines

    Directory of Open Access Journals (Sweden)

    Le Moyne L.

    2006-12-01

    Full Text Available Sur les moteurs à allumage commandé à injection multipoint on observe des désadaptations de richesse lors de fonctionnement transitoire. Ces désadaptations sont dues au dépôt, sous forme de film liquide, du carburant injecté dans le collecteur. Elles peuvent être compensées par une gestion adéquate de la masse injectée. Ainsi, afin d'obtenir la masse de carburant qui maintient la richesse constante, nous avons développé un modèle bidimensionnel des écoulements dans le collecteur au cours du cycle moteur. Ce modèle décrit l'écoulement des gaz frais, des gouttes injectées, des gaz brûlés refoulés vers l'admission et du film sur les parois, sur le principe de la séparation des phases. Nous montrons que le modèle reproduit correctement le signal de richesse et comment il permet de supprimer les désadaptations. La mesure de richesse est faite à l'échappement avec une sonde à oxygène dont nous validons le fonctionnement en transitoire avec une corrélation à la pression maximale du cycle dans le cylindre. Air-fuel ratio excursions are observed on port-injected spark ignition engines during transients. This excursions result from the liquid fuel film deposited on intake port. They can be compensated by controlling the injected fuel mass. In order to have the amount of fuel that keeps air-fuel ratio constant, we have developed a 2D model of flows in the intake port during engine cycle. This separate phases model describes the flow of fresh gases, injected droplets, hot burned gases and film on port walls. We show that the model effectively predicts the equivalence ratio and how it allows to eliminate excursions. Equivalence ratio measures are made with an oxygen sensor which functioning is validated during transients by correlating it to maximal pressure during engine cycle.

  17. Speeds in school zones.

    Science.gov (United States)

    2009-02-01

    School speed zones are frequently requested traffic controls for school areas, based on the common belief : that if the transportation agency would only install a reduced speed limit, then drivers would no longer : speed through the area. This resear...

  18. Eccentric crank variable compression ratio mechanism

    Science.gov (United States)

    Lawrence, Keith Edward [Kobe, JP; Moser, William Elliott [Peoria, IL; Roozenboom, Stephan Donald [Washington, IL; Knox, Kevin Jay [Peoria, IL

    2008-05-13

    A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

  19. Parametric study of a turbocompound diesel engine based on an analytical model

    International Nuclear Information System (INIS)

    Zhao, Rongchao; Zhuge, Weilin; Zhang, Yangjun; Yin, Yong; Zhao, Yanting; Chen, Zhen

    2016-01-01

    Turbocompounding is an important technique to recover waste heat from engine exhaust and reduce CO_2 emission. This paper presents a parametric study of turbocompound diesel engine based on analytical model. An analytical model was developed to investigate the influence of system parameters on the engine fuel consumption. The model is based on thermodynamics knowledge and empirical models, which can consider the impacts of each parameter independently. The effects of turbine efficiency, back pressure, exhaust temperature, pressure ratio and engine speed on the recovery energy, pumping loss and engine fuel reductions were studied. Results show that turbine efficiency, exhaust temperature and back pressure has great influence on the fuel reduction and optimal power turbine (PT) expansion ratio. However, engine operation speed has little impact on the fuel savings obtained by turbocompounding. The interaction mechanism between the PT recovery power and engine pumping loss is presented in the paper. Due to the nonlinear characteristic of turbine power, there is an optimum value of PT expansion ratio to achieve largest power gain. At the end, the fuel saving potential of high performance turbocompound engine and the requirements for it are proposed in the paper. - Highlights: • An analytical model for turbocompound engine is developed and validated. • Parametric study is performed to obtain lowest BSFC and optimal expansion ratio. • The influences of each parameter on the fuel saving potentials are presented. • The impact mechanisms of each parameter on the energy tradeoff are disclosed. • It provides an effective tool to guide the preliminary design of turbocompounding.

  20. The new TOYOTA 4.8L V10 petrol high performance engine for LEXUS LFA super car

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Takamitsu; Kawamura, Hiroshi; Tsukamoto, Keisuke; Nagai, Masakatsu; Uchida, Takahiro [Toyota Motor Corporation (Japan); Maruyama, Heiji [Yamaha Motor Corporation (Japan)

    2011-07-01

    The new 1LR-GUE V10 high performance engine was designed exclusively for the Lexus LFA super car (below picture). Achieving the speed and performance of a true super car was merely the starting point. The engine was developed to create a feeling of infinite acceleration potential. Response is instant and based on close understanding of driver's reactions. Vehicle handling provides unsurpassed response and feedback with ideal transient torque characteristics and marvelous sound with unique design. The performance of this engine was accomplished by combining world-class high revolution speed and high power (per liter). The new 4.8L engine produces 412kW (560hp) at 8700rpm and redline is 9000rpm (fuel cut-off speed is 9500rpm). It meets the latest emission standard Euro V and achieves good fuel consumption with a wide range stoechiometric air fuel ratio, till speeds up to 240km/h. (orig.)

  1. Experimental Study of the Gas Engine Driven Heat Pump with Engine Heat Recovery

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2015-01-01

    Full Text Available Gas engine driven heat pumps (GEHPs represent one of practical solutions to effectively utilize fossil fuel energy and reduce environmental pollution. In this paper, the performance characteristics of the GEHP were investigated experimentally with engine heat recovery. A GEHP test facility was set up for this purpose. The effects of several important factors including engine speed, ambient temperature, condenser water flow rate, and condenser water inlet temperature on the system performance were studied over a wide range of operating conditions. The results showed that the engine waste heat accounted for about 40–50% of the total heat capacity over the studied operating conditions. It also showed that engine speed and ambient temperature had significant effects on the GEHP performance. The coefficient of performance (COP and the primary energy ratio (PER decreased by 14% and 12%, respectively, as engine speed increased from 1400 rpm to 2000 rpm. On the other hand, the COP and PER of the system increased by 22% and 16%, respectively, with the ambient temperature increasing from 3 to 12°C. Furthermore, it was demonstrated that the condenser water flow rate and condenser water inlet temperature had little influence on the COP of the heat pump and the PER of the GEHP system.

  2. Experimental investigations of LPG use at the automotive diesel engine

    Directory of Open Access Journals (Sweden)

    Nutu Cristian

    2017-01-01

    Full Text Available The liquefied petroleum gas has a great potential to improve energetically and pollution performance of compression ignition engines due to its good combustion properties. This paper presents results of the researches carried on a car compression ignition engine with a 1.5 dm3 displacement, fuelled with diesel fuel and liquefied petroleum gas by diesel-gas method at the operating regimens of 70% and 55% engine load, engine speed of 2000 rpm and for substitute ratios between (6–19%. A specific objective of this paper is to establish a correlation between the optimum adjustments and the substitute ratio of the diesel fuel with liquefied petroleum gas for the investigated regimens to limit the maximum pressure and smoke level, knock and rough engine functioning and having regard to decrease the fuel consumption and the level of the pollutant emissions.

  3. Dynamic control of a homogeneous charge compression ignition engine

    Science.gov (United States)

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

    2008-06-03

    A homogenous charge compression ignition engine is operated by compressing a charge mixture of air, exhaust and fuel in a combustion chamber to an autoignition condition of the fuel. The engine may facilitate a transition from a first combination of speed and load to a second combination of speed and load by changing the charge mixture and compression ratio. This may be accomplished in a consecutive engine cycle by adjusting both a fuel injector control signal and a variable valve control signal away from a nominal variable valve control signal. Thereafter in one or more subsequent engine cycles, more sluggish adjustments are made to at least one of a geometric compression ratio control signal and an exhaust gas recirculation control signal to allow the variable valve control signal to be readjusted back toward its nominal variable valve control signal setting. By readjusting the variable valve control signal back toward its nominal setting, the engine will be ready for another transition to a new combination of engine speed and load.

  4. Solar engine system

    International Nuclear Information System (INIS)

    Tan, K.K.; Bahrom Sanugi; Chen, L.C.; Chong, K.K.; Jasmy Yunus; Kannan, K.S.; Lim, B.H.; Noriah Bidin; Omar Aliman; Sahar Salehan; Sheikh Ab Rezan Sheikh A H; Tam, C.M.; Chen, Y.T.

    2001-01-01

    This paper reports the revolutionary solar engine system in Universiti Teknologi Malaysia (UTM). The solar engine is a single cylinder stirling engine driven by solar thermal energy. A first prototype solar engine has been built and demonstrated. A new-concept non-imaging focusing heliostat and a recently invented optical receiver are used in the demonstration. Second generation of prototype solar engine is described briefly. In this paper, the solar engine system development is reported. Measurement for the first prototype engine speed, temperature and specifications are presented. The benefits and potential applications for the future solar engine system, especially for the electricity generating aspect are discussed. (Author)

  5. Experimental investigation and phenomenological model development of flame kernel growth rate in a gasoline fuelled spark ignition engine

    International Nuclear Information System (INIS)

    Salvi, B.L.; Subramanian, K.A.

    2015-01-01

    Highlights: • Experimental measurement of the flame kernel growth rate (FKGR) in SI engine. • FKGR is the highest at MBT timing as compared with retarded and advanced timings. • FKGR decreases with increase in engine speed. • FKGR is correlated with equivalence ratio, charge density, in-cylinder pressure and engine speed. - Abstract: As flame kernel growth plays a major role in combustion of premixed-charge in spark ignition engines for higher energy efficiency and less emission, the experimental study was carried out on a single cylinder spark ignition research engine for measurement of flame kernel growth rate (FKGR) using spark plug fibre optics probe (VisioFlame sensor). The FKGR was measured on the engine at different power output with varied spark ignition timings and different engine speeds. The experimental results indicate that the FKGR was the highest with the maximum brake torque (MBT) spark timing and it decreases with increase in the engine speed. The FKGR at engine speed of 1000 RPM was the highest of 1.81 m/s with MBT timing (20° bTDC) as compared to 1.6 m/s (15° bTDC), 1.67 m/s (25° bTDC), and 1.61 m/s (30° bTDC) with retarded and advanced timing. In addition to this, a phenomenological model was developed for calculation of FKGR. It was observed from the model that FKGR is function of equivalence ratio, engine speed, in-cylinder pressure and charge density. The experimental results and methodology emerged from this study would be useful for optimization of engine parameters using the FKGR and also further development of model for alternative fuels

  6. Analysis and simulation of Wiseman hypocycloid engine

    Directory of Open Access Journals (Sweden)

    Priyesh Ray

    2014-12-01

    Full Text Available This research studies an alternative to the slider-crank mechanism for internal combustion engines, which was proposed by the Wiseman Technologies Inc. Their design involved replacing the crankshaft with a hypocycloid gear assembly. The unique hypocycloid gear arrangement allowed the piston and connecting rod to move in a straight line creating a perfect sinusoidal motion, without any side loads. In this work, the Wiseman hypocycloid engine was modeled in a commercial engine simulation software and compared to slider-crank engine of the same size. The engine’s performance was studied, while operating on diesel, ethanol, and gasoline fuel. Furthermore, a scaling analysis on the Wiseman engine prototypes was carried out to understand how the performance of the engine is affected by increasing the output power and cylinder displacement. It was found that the existing 30cc Wiseman engine produced about 7% less power at peak speeds than the slider-crank engine of the same size. These results were concurrent with the dynamometer tests performed in the past. It also produced lower torque and was about 6% less fuel efficient than the slider-crank engine. The four-stroke diesel variant of the same Wiseman engine performed better than the two-stroke gasoline version. The Wiseman engine with a contra piston (that allowed to vary the compression ratio showed poor fuel efficiency but produced higher torque when operating on E85 fuel. It also produced about 1.4% more power than while running on gasoline. While analyzing effects of the engine size on the Wiseman hypocycloid engine prototypes, it was found that the engines performed better in terms of power, torque, fuel efficiency, and cylinder brake mean effective pressure as the displacement increased. The 30 horsepower (HP conceptual Wiseman prototype, while operating on E85, produced the most optimum results in all aspects, and the diesel test for the same engine proved to be the most fuel efficient.

  7. A study on emission characteristics of an EFI engine with ethanol blended gasoline fuels

    Science.gov (United States)

    He, Bang-Quan; Wang, Jian-Xin; Hao, Ji-Ming; Yan, Xiao-Guang; Xiao, Jian-Hua

    The effect of ethanol blended gasoline fuels on emissions and catalyst conversion efficiencies was investigated in a spark ignition engine with an electronic fuel injection (EFI) system. The addition of ethanol to gasoline fuel enhances the octane number of the blended fuels and changes distillation temperature. Ethanol can decrease engine-out regulated emissions. The fuel containing 30% ethanol by volume can drastically reduce engine-out total hydrocarbon emissions (THC) at operating conditions and engine-out THC, CO and NO x emissions at idle speed, but unburned ethanol and acetaldehyde emissions increase. Pt/Rh based three-way catalysts are effective in reducing acetaldehyde emissions, but the conversion of unburned ethanol is low. Tailpipe emissions of THC, CO and NO x have close relation to engine-out emissions, catalyst conversion efficiency, engine's speed and load, air/fuel equivalence ratio. Moreover, the blended fuels can decrease brake specific energy consumption.

  8. Measures for speed management.

    NARCIS (Netherlands)

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather

  9. Recent technologies for reduction of aircraft propulsion noise. Kokuki engine soon teigenka no saikin no gijutsu shinpo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H [National Aerospace Lab., Chofu, Tokyo (Japan)

    1994-03-10

    Inside the jet engine, the propulsion engine for an aircraft, a high speed air current is flowing, and the rotors such as the fan, compress or, turbine and so forth are rotating with a high speed in its flowing current. The flow itself in which a high speed exhaust jet is discharged in the air from engine exhaust port, and the aerodynamic noise generated by an interaction of the flow with the material bodies are the main noise sources of the aircraft engine. Because the supersonic planes are necessary to fly with mach number 2 - 3 during cruising, the turbojet engine with a large jet exhaust speed or the low bypass ratio turbofan engine is selected. Since a noise reduction by reducing the jet exhaust speed, which was an effective measure for the high subsonic speed passenger plane, can not be applied, a reduction of the supersonic jet noise, which is hard to be reduced, becomes a necessity. In addition, in recent years, a research and development of the advanced turbo prop (ATP) aircraft with a further higher thrust efficiency are advanced as well. The aerodynamical noise reduction technologies of these engines for supersonic airplanes are summarized. 14 refs., 11 figs., 1 tab.

  10. Engine design optimization for running on ethanol with low emissions

    Energy Technology Data Exchange (ETDEWEB)

    Gjirja, S [Chalmers Univ. of Technology, Gothenburg (Sweden). Dept. of Thermo- and Fluid Dynamics

    1996-05-01

    The aim of this project was to optimize the Volvo AH10A245 engine design parameters for ethanol fuel with Beraid (Trade mark of the ignition improver manufactured by the Akzo Nobel Surface Chemistry AB). The method used was engine testing with variation of design, performance, and other functional parameters, which affect the engine thermodynamics, and exhaust gas composition. The first design parameter, which was tested and optimized was the compression ratio, which was optimized at the ratio of 23:1. In order to prevail the fuel spray impingement, which might affect the unburned or partially burned emissions (CO), the combustion chamber was redesigned to a straight-side wall bowl in piston. Furthermore, the injector position was optimized by means of lifting or descending it few millimeters. The best emission levels was achieved with the injector lift of 1.00 mm. The inlet air temperature was optimized for lower emissions by removing the intercooler thermostat. Injector nozzles with different cross section areas of holes were tested, and the 6 holes injector nozzles with smaller cross sectional area, compared with base nozzles, were selected. The engine performance was maintained for lower engine rated speed 2000 (instead of 2200 rpm for conventional engine) and lower intermediate speed 1250 (instead of 1320 rpm for conventional engine). Such engine performance optimization was followed by the improved specific fuel consumption, and lower emissions compared with conventional speeds. The backpressure governor, desperately needed during the first phase of engine design optimization was, finally avoided. It can only be used as in the conventional diesel engine. 7 refs, 26 figs, 18 tabs, 7 appendices

  11. Design and Checkout of a High Speed Research Nozzle Evaluation Rig

    Science.gov (United States)

    Castner, Raymond S.; Wolter, John D.

    1997-01-01

    The High Flow Jet Exit Rig (HFJER) was designed to provide simulated mixed flow turbojet engine exhaust for one- seventh scale models of advanced High Speed Research test nozzles. The new rig was designed to be used at NASA Lewis Research Center in the Nozzle Acoustic Test Rig and the 8x6 Supersonic Wind Tunnel. Capabilities were also designed to collect nozzle thrust measurement, aerodynamic measurements, and acoustic measurements when installed at the Nozzle Acoustic Test Rig. Simulated engine exhaust can be supplied from a high pressure air source at 33 pounds of air per second at 530 degrees Rankine and nozzle pressure ratios of 4.0. In addition, a combustion unit was designed from a J-58 aircraft engine burner to provide 20 pounds of air per second at 2000 degrees Rankine, also at nozzle pressure ratios of 4.0. These airflow capacities were designed to test High Speed Research nozzles with exhaust areas from eighteen square inches to twenty-two square inches. Nozzle inlet flow measurement is available through pressure and temperature sensors installed in the rig. Research instrumentation on High Speed Research nozzles is available with a maximum of 200 individual pressure and 100 individual temperature measurements. Checkout testing was performed in May 1997 with a 22 square inch ASME long radius flow nozzle. Checkout test results will be summarized and compared to the stated design goals.

  12. Modelling of wander ratios, travel speeds and productivity of cable ...

    African Journals Online (AJOL)

    The study, however, found that both cable and grapple skidders were only hauling approximately 50% of their capacity and for that reason multiple regression models to predict potential production at full payload capacity were developed for the two skidder configurations. Multiple regression was also used to develop ...

  13. Comparison of Engine Simulation Software for Development of Control System

    Directory of Open Access Journals (Sweden)

    KinYip Chan

    2013-01-01

    Full Text Available Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine components. However, engine control involves different operating parameters. Various sensors are installed into the engine, the combustion performance is recorded, and data is sent to engine control unit (ECU. ECU computes the new set of parameters to make fine adjustments to actuators providing better engine performance. Such techniques include variable valve timing, variable ignition timing, variable air to fuel ratio, and variable compression ratio. In the present study, two of the commercial packages, Ricardo Wave and Lotus Engine Simulation, have been tested on the capabilities for engine control purposes. These packages are compared with an in-house developed package and with reference results available from the literature. Different numerical experiments have been carried out from which it can be concluded that all packages predict similar profiles of pressure and temperature in the engine cylinder. Moreover, those are in reasonable agreement with the reference results while in-house developed package is possible to run simulations with changing speed for engine control purpose.

  14. Fluids engineering

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  15. Experimental Investigation of the Effects of Some Operating Diesel Engine Variables on Emitted Particulate Matters (PM

    Directory of Open Access Journals (Sweden)

    Adel M. Saleh

    2012-03-01

    Full Text Available The diesel engine is the most efficient prime mover commonly available today. Diesel engines move a large portion of the world’s goods, power much of the world’s equipment, and generate electricity more economically than any other device in their size range. But the diesel is one of the largest contributors to environmental pollution problems worldwide, and will remain so, with large increases expected in vehicle population. This experimental study has been conducted with direct injection diesel engine and particulate matters (PM concentrations were measured at variable operating variables. The results show that PM concentrations influence by changing equivalence ratio, load, engine speed and injection timing

  16. Combustion characteristics of lemongrass (Cymbopogon flexuosus) oil in a partial premixed charge compression ignition engine

    OpenAIRE

    Avinash Alagumalai

    2015-01-01

    Indeed, the development of alternate fuels for use in internal combustion engines has traditionally been an evolutionary process in which fuel-related problems are met and critical fuel properties are identified and their specific limits defined to resolve the problem. In this regard, this research outlines a vision of lemongrass oil combustion characteristics. In a nut-shell, the combustion phenomena of lemongrass oil were investigated at engine speed of 1500 rpm and compression ratio of 17....

  17. Large Aspect Ratio Tokamak Study

    International Nuclear Information System (INIS)

    Reid, R.L.; Holmes, J.A.; Houlberg, W.A.; Peng, Y.K.M.; Strickler, D.J.; Brown, T.G.; Wiseman, G.W.

    1980-06-01

    The Large Aspect Ratio Tokamak Study (LARTS) at Oak Ridge National Laboratory (ORNL) investigated the potential for producing a viable longburn tokamak reactor by enhancing the volt-second capability of the ohmic heating transformer through the use of high aspect ratio designs. The plasma physics, engineering, and economic implications of high aspect ratio tokamaks were assessed in the context of extended burn operation. Using a one-dimensional transport code plasma startup and burn parameters were addressed. The pulsed electrical power requirements for the poloidal field system, which have a major impact on reactor economics, were minimized by optimizing the startup and shutdown portions of the tokamak cycle. A representative large aspect ratio tokamak with an aspect ratio of 8 was found to achieve a burn time of 3.5 h at capital cost only approx. 25% greater than that of a moderate aspect ratio design tokamak

  18. Speed management program plan.

    Science.gov (United States)

    2014-05-01

    Changing public attitudes regarding speeding and speed management will require a comprehensive and concerted effort, involving a wide variety of strategies. This plan identifies six primary focus areas: : A. Data and Data-Driven Approaches, : B. Rese...

  19. Small portable speed calculator

    Science.gov (United States)

    Burch, J. L.; Billions, J. C.

    1973-01-01

    Calculator is adapted stopwatch calibrated for fast accurate measurement of speeds. Single assembled unit is rugged, self-contained, and relatively inexpensive to manufacture. Potential market includes automobile-speed enforcement, railroads, and field-test facilities.

  20. Electric vehicle speed control

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, W.R.; Mc Auliffe, G.N.; Schlageter, G.A.

    1987-06-23

    This patent describes an electric vehicle driven by a DC motor. The vehicle has a field winding, an electric resistance element in circuit with the field winding, a switch in the circuit operative when closed to place. The element in parallel with the field winding weakens the field and increases potential motor speed. Also are relay means for operating the switch, means to determine motor speed, computer means for determining whether the motor speed is increasing or decreasing, and means for operating the relay means to close the switch at a first speed. If the motor speed is increased, it actuates the switch at a second speed lower than the first speed but only if switch has been closed previously and motor speed is decreasing.

  1. Combustion Temperature Effect of Diesel Engine Convert to Compressed Natural Gas Engine

    OpenAIRE

    Semin; Abdul R. Ismail; Rosli A. Bakar

    2009-01-01

    Effect of combustion temperature in the engine cylinder of diesel engine convert to Compressed Natural Gas (CNG) engine was presents in this study. The objective of this study was to investigate the engine cylinder combustion temperature effect of diesel engine convert to CNG engine on variation engine speed. Problem statement: The hypothesis was that the lower performance of CNG engine was caused by the effect of lower in engine cylinder temperature. Are the CNG engine is lower cylinder temp...

  2. Thermodynamic analysis of an HCCI engine based system running on natural gas

    International Nuclear Information System (INIS)

    Djermouni, Mohamed; Ouadha, Ahmed

    2014-01-01

    Highlights: • A thermodynamic analysis of an HCCI based system has been carried out. • A thermodynamic model has been developed taking into account the gas composition resulting from the combustion process. • The specific heat of the working fluid is temperature dependent. - Abstract: This paper attempts to carry out a thermodynamic analysis of a system composed of a turbocharged HCCI engine, a mixer, a regenerator and a catalytic converter within the meaning of the first and the second law of thermodynamics. For this purpose, a thermodynamic model has been developed taking into account the gas composition resulting from the combustion process and the specific heat temperature dependency of the working fluid. The analysis aims in particular to examine the influence of the compressor pressure ratio, ambient temperature, equivalence ratio, engine speed and the compressor isentropic efficiency on the performance of the HCCI engine. Results show that thermal and exergetic efficiencies increase with increasing the compressor pressure ratio. However, the increase of the ambient temperature involves a decrease of the engine efficiencies. Furthermore, the variation of the equivalence ratio improves considerably both thermal and exergetic efficiencies. As expected, the increase of the engine speed enhances the engine performances. Finally, an exergy losses mapping of the system show that the maximum exergy losses occurs in the HCCI engine

  3. Adaptive Gas Turbine Engine Control for Deterioration Compensation Due to Aging

    Science.gov (United States)

    Litt, Jonathan S.; Parker, Khary I.; Chatterjee, Santanu

    2003-01-01

    This paper presents an ad hoc adaptive, multivariable controller tuning rule that compensates for a thrust response variation in an engine whose performance has been degraded though use and wear. The upset appears when a large throttle transient is performed such that the engine controller switches from low-speed to high-speed mode. A relationship was observed between the level of engine degradation and the overshoot in engine temperature ratio, which was determined to cause the thrust response variation. This relationship was used to adapt the controller. The method is shown to work very well up to the operability limits of the engine. Additionally, since the level of degradation can be estimated from sensor data, it would be feasible to implement the adaptive control algorithm on-line.

  4. Taguchi Method for Investigating the Performance Parameters and Exergy of a Diesel Engine Using Four Types of Diesel Fuels

    Directory of Open Access Journals (Sweden)

    Dara K. Khidir

    2016-05-01

    Full Text Available The effects of changes in engine operating parameters, i.e., engine speed, throttle and water temperature, for four types of diesel fuel (A, B, C and D of different specific gravities, as supplied from local market and refineries, were studied and simultaneously optimized. The experiment design was based on Taguchi’s “L' 16” orthogonal table, and the engine was put to test at different engine speeds, throttling opening percentages and water temperatures, using different fuels. The data were analyzed using S/N (signal to noise ratio for each factor. The obtained results show that the optimum operating conditions for minimum BSFC (brake specific fuel consumption are achieved when the engine speed is 2500 rpm, the throttle is placed at 75% of full throttling, the water temperature is 80 oC and the engine is using fuel type D. Also, results of S/N ratio reveal that the throttle has significant influence on brake thermal and exergic efficiencies. Water temperature is the second most effective factor and then comes the influence of engine speed. The least effective factor among the studied parameters for the types of fuel considered in this experiment is the fuel type.

  5. Genetically engineered foods

    Science.gov (United States)

    Bioengineered foods; GMOs; Genetically modified foods ... helps speed up the process of creating new foods with desired traits. The possible benefits of genetic engineering include: More nutritious food Tastier food Disease- and ...

  6. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  7. Simultaneously firing two cylinders of an even firing camless engine

    Science.gov (United States)

    Brennan, Daniel G

    2014-03-11

    A valve control system includes an engine speed control module that determines an engine speed and a desired engine stop position. A piston position module determines a desired stopping position of a first piston based on the desired engine stop position. A valve control module receives the desired stopping position, commands a set of valves to close at the desired stopping position if the engine speed is less than a predetermined shutdown threshold, and commands the set of valves to reduce the engine speed if the engine speed is greater than the predetermined shutdown threshold.

  8. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    Science.gov (United States)

    Patond, S. B.; Chaple, S. A.; Shrirao, P. N.; Shaikh, P. I.

    2013-06-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al2O3·2SiO2 (mullite) (Al2O3 = 60%, SiO2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  9. Comparative Study of Performance and Combustion Characteristics of Conventional and Low Heat Rejection (Mullite Coated) Diesel Engines

    International Nuclear Information System (INIS)

    Patond, S B; Chaple, S A; Shrirao, P N; Shaikh, P I

    2013-01-01

    Tests were performed on a single cylinder, four stroke, direct injection, diesel engine whose piston crown, cylinder head and valves were coated with a 0.5 mm thickness of 3Al 2 O 3 ·2SiO 2 (mullite) (Al 2 O 3 = 60%, SiO 2 = 40%) over a 150 μm thickness of NiCrAlY bond coat. The working conditions for the conventional engine (without coating) and LHR (mullite coated) engine were kept exactly same to ensure a comparison between the two configurations of the engine. This paper is intended to emphasis on performance and combustion characteristics of conventional and LHR (Mullite coated) diesel engines under identical conditions. Tests were carried out at same operational constraints i.e. air-fuel ratio and engine speed conditions for both conventional engine (without coating) and LHR (mullite coated) engines. The results showed that, there was as much as 1.8 % increasing on brake power for LHR (mullite coated) engine compared to conventional engine (without coating) at full load The average decrease in brake specific fuel consumption in the LHR engine compared with the conventional engine was 1.76 % for full engine load. However, there was increasing on cylinder gas pressure and net heat release rate for LHR engine compared to conventional engine. Also the results revealed that, there was as much as 22% increasing on exhaust gas temperature for LHR engine compared to conventional engine at full engine load.

  10. Research on fuzzy PID control to electronic speed regulator

    Science.gov (United States)

    Xu, Xiao-gang; Chen, Xue-hui; Zheng, Sheng-guo

    2007-12-01

    As an important part of diesel engine, the speed regulator plays an important role in stabilizing speed and improving engine's performance. Because there are so many model parameters of diesel-engine considered in traditional PID control and these parameters present non-linear characteristic.The method to adjust engine speed using traditional PID is not considered as a best way. Especially for the diesel-engine generator set. In this paper, the Fuzzy PID control strategy is proposed. Some problems about its utilization in electronic speed regulator are discussed. A mathematical model of electric control system for diesel-engine generator set is established and the way of the PID parameters in the model to affect the function of system is analyzed. And then it is proposed the differential coefficient must be applied in control design for reducing dynamic deviation of system and adjusting time. Based on the control theory, a study combined control with PID calculation together for turning fuzzy PID parameter is implemented. And also a simulation experiment about electronic speed regulator system was conducted using Matlab/Simulink and the Fuzzy-Toolbox. Compared with the traditional PID Algorithm, the simulated results presented obvious improvements in the instantaneous speed governing rate and steady state speed governing rate of diesel-engine generator set when the fuzzy logic control strategy used.

  11. The Influence of Injection Timing on Performance Characteristics of Diesel Engine Using Jatropha Biodiesel with and without Partial Hydrogenation

    Directory of Open Access Journals (Sweden)

    Rizqon Fajar

    2014-07-01

    Full Text Available Experimental research has been conducted to investigate the effects of blend of hydrogenated and unhydrogenated Jatropha biodiesel with diesel fuel in volume ratio of 30:70 (B30 on combustion characteristics (BSFC, thermal efficiency and smoke emission of single cylinder diesel engine. In this experiment, engine speed was kept constant at 1,500, 2,500, and 3,500 rpm with maximum engine load at BMEP 5 bar and injection timings were varied. Experimental result showed that at engine speed 1,500 rpm, BSFC of B30 hydrogenated and unhydrogenated Jatropha biodiesel were higher than it of diesel fuel at all injection timings (10° to 18° BTDC. At the same condition, partial hydrogenated Jatropha biodiesel showed higher BSFC than unhydrogenated Jatropha biodiesel. However, the difference in BSFC became smaller for all fuels at engine speed 2,500 rpm and 3,500 rpm at all injection timing. Jatropha biodiesel with and without partial hydrogenation tend to have higher thermal efficiency compared with diesel fuel at all engine speed and injection timing. The best injection timings to operate B30 Jatropha biodiesel with and without hydrogenation were 14°, 18° and 24° BTDC at engine speed 1,500, 2,500, and 3,500 rpm respectively. This conclusion was deduced based on the minimum value of BSFC and the maximum value of thermal efficiency. Smoke emissions for all fuels were in the same level for all conditions.

  12. Speed in Acquisitions

    DEFF Research Database (Denmark)

    Meglio, Olimpia; King, David R.; Risberg, Annette

    2017-01-01

    The advantage of speed is often invoked by academics and practitioners as an essential condition during post-acquisition integration, frequently without consideration of the impact earlier decisions have on acquisition speed. In this article, we examine the role speed plays in acquisitions across...... the acquisition process using research organized around characteristics that display complexity with respect to acquisition speed. We incorporate existing research with a process perspective of acquisitions in order to present trade-offs, and consider the influence of both stakeholders and the pre......-deal-completion context on acquisition speed, as well as the organization’s capabilities to facilitating that speed. Observed trade-offs suggest both that acquisition speed often requires longer planning time before an acquisition and that associated decisions require managerial judgement. A framework for improving...

  13. CONVERSION OF DIESEL ENGINE INTO SPARK IGNITION ENGINE TO WORK WITH CNG AND LPG FUELS FOR MEETING NEW EMISSION NORMS

    Directory of Open Access Journals (Sweden)

    Syed Kaleemuddin

    2010-01-01

    Full Text Available Fluctuating fuel prices and associated pollution problems of largely exploited petroleum liquid fuel has stimulated the research on abundantly available gaseous fuels to keep the mobility industry intact. In the present work an air cooled diesel engine was modified suitably into a spark ignition engine incorporating electronic ignition and variable speed dependant spark timing to accommodate both LPG and CNG as fuels. Engine was optimized for stoichiometric operation on engine dynamometer. Materials of a few intricate engine components were replaced to suit LPG and CNG application. Ignition timing was mapped to work with gaseous fuels for different speeds. Compensation was done for recovering volumetric efficiency when operated with CNG by introducing more volume of air through resonator. Ignition timing was observed to be the pertinent parameter in achieving good performance with gaseous fuels under consideration. Performance and emission tests were carried out on engine dynamometer and chassis dynamometer. Under wide open throttle and at rated speed condition, it was observed that the peak pressure with LPG was lying between diesel fuel and CNG fuel operation due to slow burning nature of gaseous fuels. As compression ratio was maintained same for LPG and CNG fuel operation, low CO emissions were observed with LPG where as HC + NOx emissions were lower with CNG fuel operation. Chassis dynamometer based emission tests yielded lower CO2 levels with CNG operation.

  14. Speed of adjustment: Evidence from Borsa Istanbul

    Directory of Open Access Journals (Sweden)

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  15. Effect of external hot EGR dilution on combustion, performance and particulate emissions of a GDI engine

    International Nuclear Information System (INIS)

    Xie, Fangxi; Hong, Wei; Su, Yan; Zhang, Miaomiao; Jiang, Beiping

    2017-01-01

    Highlights: • Effect of hot EGR on combustion and PN emission is investigated on a GDI engine. • Appropriate addition of hot EGR can reduce fuel consumption, NO_x and PN emission. • Relationship between BSFC and emissions of hot EGR is better than cooled EGR. • Condition with low-medium speeds and medium loads are more suitable for hot EGR. - Abstract: In this paper, an experimental investigation about the influence of hot EGR addition on the engine combustion, performance and particulate number emission was conducted at a spark-ignition gasoline direct injection (GDI) engine. Meanwhile, the different effects between cooled and hot EGR addition methods were compared and the variations of fuel consumption and particle number emissions under six engine operating conditions with different speeds and loads were analyzed. The research result indicated that increasing hot EGR ratio properly with adjustment of ignition timing could effectively improve the relationship among brake-specific fuel consumption (BSFC), NO_x and particle number emissions. When hot EGR ratio increased to 20%, not only BSFC but also the NO_x and particle number emissions were reduced, which were about 7%, 87% and 36% respectively. Compared with cooled EGR, the flame development and propagation speeds were accelerated, and cycle-by-cycle combustion variation decreased with hot EGR. Meanwhile, using hot EGR made the engine realize a better relationship among fuel consumption, NO_x and particle number emissions. The biggest improvements of BSFC, NO_x and particle number emissions were obtained at low-medium speed and medium load engine conditions by hot EGR addition method. While engine speed increased and load decreased, the improvement of engine fuel consumption and emission reduced with hot EGR method.

  16. Transistorized ignition system for internal combustion engines, in particular for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Mieras, L F; Skay, F

    1977-05-12

    The invention concerns an ignition system for motor vehicles with solid state control of the power transistor switching the primary current of the ignition coil. A pulse generator driven by the engine is used for this, whose voltage pulses control the switching on of the power transistor and increase in a certain ratio to the engine speed. This ensures that the closing angle, i.e. the mechanical angle of rotation which the machine passes through while loading the ignition coil with mechanical energy, is automatically changed so that for low speeds it is just sufficient for certain ignition, but increases with increasing speed, so that the required ignition energy is always available. At low speeds one avoids charging current flowing through the primary winding of the ignition coil for longer than necessary and thus wasting electrical energy.

  17. Holes at High Blowing Ratios

    Directory of Open Access Journals (Sweden)

    Phillip M. Ligrani

    1996-01-01

    Full Text Available Experimental results are presented which describe the development and structure of flow downstream of a single row of holes with compound angle orientations producing film cooling at high blowing ratios. This film cooling configuration is important because similar arrangements are frequently employed on the first stage of rotating blades of operating gas turbine engines. With this configuration, holes are spaced 6d apart in the spanwise direction, with inclination angles of 24 degrees, and angles of orientation of 50.5 degrees. Blowing ratios range from 1.5 to 4.0 and the ratio of injectant to freestream density is near 1.0. Results show that spanwise averaged adiabatic effectiveness, spanwise-averaged iso-energetic Stanton number ratios, surveys of streamwise mean velocity, and surveys of injectant distributions change by important amounts as the blowing ratio increases. This is due to injectant lift-off from the test surface just downstream of the holes.

  18. [Particulate distribution characteristics of Chinese phrase V diesel engine based on butanol-diesel blends].

    Science.gov (United States)

    Lou, Di-Ming; Xu, Ning; Fan, Wen-Jia; Zhang, Tao

    2014-02-01

    With a common rail diesel engine without any modification and the engine exhaust particle number and particle size analyzer EEPS, this study used the air-fuel ratio to investigate the particulate number concentration, mass concentration and number distribution characteristics of a diesel engine fueled with butanol-diesel blends (Bu10, Bu15, Bu20, Bu30 and Bu40) and petroleum diesel. The results show: for all test fuels, the particle number distributions turn to be unimodal. With the increasing of butanol, numbers of nucleation mode particles and small accumulation mode particle decrease. At low speed and low load conditions, the number of large accumulation mode particle increases slightly, but under higher speed and load conditions, the number does not increase. When the fuels contain butanol, the total particle number concentration and mass concentration in all conditions decrease and that is more obvious at high speed load.

  19. Investigation of the Behavior of Fuel in the Intake Manifold and its Relation to S. I. Engines, 1980-1983

    Science.gov (United States)

    Servati, Hamid Beyragh

    A liquid fuel film formation on the walls of an intake manifold adversely affects the engine performance and alters the overall air/fuel ratio from that scheduled by a fuel injector or carburetor and leads to adverse effects in vehicle driveability, exhaust emissions, and fuel economy. In this dissertation, the intake manifold is simulated by a horizontal circular duct. A model is provided to predict the rate of deposition and evaporation of the droplets in the intake manifold. The liquid fuel flow rate into the cylinders, mean film velocity and film thickness are determined as functions of engine parameters for both steady and transient operating conditions of the engine. A mathematical engine model is presented to simulate the dynamic interactions of the various engine components such as the air/fuel inlet element, intake manifold, combustion, dynamics and exhaust emissions. Inputs of the engine model are the intake manifold pressure and temperature, throttle angle, and air/fuel ratio. The observed parameters are the histories of fuel film thickness and velocity, fuel consumption, engine speed, engine speed hesitation time, and histories of CO, CO(,2), NO(,x), CH(,n), and O(,2). The effects of different air/fuel ratio control strategies on engine performance and observed parameters are also shown.

  20. Use of a single-zone thermodynamic model with detailed chemistry to study a natural gas fueled homogeneous charge compression ignition engine

    International Nuclear Information System (INIS)

    Zheng Junnian; Caton, Jerald A.

    2012-01-01

    Highlights: ► Auto-ignition characteristics of a natural gas fueled HCCI engine. ► Engine speed had the greatest effect on the auto-ignition process. ► Increases of C 2 H 6 or C 3 H 8 improved the auto-ignition process. ► Engine performance was not sensitive to small changes in C 2 H 6 or C 3 H 8 . ► Nitric oxides concentrations decreased as engine speed or EGR level was increased. - Abstract: A single zone thermodynamic model with detailed chemical kinetics was used to simulate a natural gas fueled homogeneous charge compression ignition (HCCI) engine. The model employed Chemkin and used chemical kinetics for natural gas with 53 species and 325 reactions. This simulation was used to complete analyses for a modified 0.4 L single cylinder engine. The engine possessed a compression ratio of 21.5:1, and had a bore and stroke of 86 and 75 mm, respectively. Several sets of parametric studies were completed to investigate the minimal initial temperature, engine performance, and nitric oxide emissions of HCCI engine operation. The results show significant changes in combustion characteristics with varying engine operating conditions. Effects of varying equivalence ratios (0.3–1.0), engine speeds (1000–4000 RPM), EGR (0–40%), and fuel compositions were determined and analyzed in detail. In particular, every 0.1 increase in equivalence ratio or 500 rpm increase in engine speed requires about a 5 K higher initial temperature for complete combustion, and leads to around 0.7 bar increase in IMEP.

  1. Speed and income

    DEFF Research Database (Denmark)

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  2. High speed atom source

    International Nuclear Information System (INIS)

    Hoshino, Hitoshi.

    1990-01-01

    In a high speed atom source, since the speed is not identical between ions and electrons, no sufficient neutralizing effect for ionic rays due to the mixing of the ionic rays and the electron rays can be obtained failing to obtain high speed atomic rays at high density. In view of the above, a speed control means is disposed for equalizing the speed of ions forming ionic rays and the speed of electrons forming electron rays. Further, incident angle of the electron rays and/or ionic rays to a magnet or an electrode is made variable. As a result, the relative speed between the ions and the electrons to the processing direction is reduced to zero, in which the probability of association between the ions and the electrons due to the coulomb force is increased to improve the neutralizing efficiency to easily obtain fine and high density high speed electron rays. Further, by varying the incident angle, a track capable of obtaining an ideal mixing depending on the energy of the neutralized ionic rays is formed. Since the high speed electron rays has such high density, they can be irradiated easily to the minute region of the specimen. (N.H.)

  3. Computer ray tracing speeds.

    Science.gov (United States)

    Robb, P; Pawlowski, B

    1990-05-01

    The results of measuring the ray trace speed and compilation speed of thirty-nine computers in fifty-seven configurations, ranging from personal computers to super computers, are described. A correlation of ray trace speed has been made with the LINPACK benchmark which allows the ray trace speed to be estimated using LINPACK performance data. The results indicate that the latest generation of workstations, using CPUs based on RISC (Reduced Instruction Set Computer) technology, are as fast or faster than mainframe computers in compute-bound situations.

  4. INFLUENCE OF OPERABILITY CRITERIA LIMITING VALUES ON SHIP SPEED

    Directory of Open Access Journals (Sweden)

    Jasna Prpić-Oršić

    2016-09-01

    Full Text Available When the ship is caught in heavy seas, there are two manoeuvres that the shipmaster can undertake to avoid excessive ship motion and hull damage: changing course or voluntary speed reduction. This paper presents a study of the effect of the various voluntary speed reduction criteria to attainable speed of ship on seaway. The speed loss is calculated by taking into account wind and wave effect on ship speed, the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed for ship in head, following and beam waves by accounting for voluntary speed reduction is estimated for various significant wave height. The criteria of slamming, deck wetness, propeller emergence, excessive accelerations and roll are taken into account. The impact of variations of the limiting values of certain criteria due to which the captain intentionally reduces the ship speed is analysed and discussed.

  5. Two-stroke engine with gaseous and liquid fuel injection

    Energy Technology Data Exchange (ETDEWEB)

    Laursen, Rene Sejer [MAN Diesel and Turbo SE, Copenhagen (Denmark)

    2012-08-15

    The need to lower emissions of CO{sub 2}, NO{sub x}, SO{sub x} and particulates as well as rising oil prices have increased engine operators' interest in alternative fuels and fuel flexibility. The low speed two-stroke ME-GI and ME-LGI dual-fuel engines with diesel pilot injection from MAN Diesel and Turbo offer the opportunity of utilising fuels such as LNG, LPG, and methanol in a wide range of liquid to gaseous fuel ratios. (orig.)

  6. High speed railway track dynamics models, algorithms and applications

    CERN Document Server

    Lei, Xiaoyan

    2017-01-01

    This book systematically summarizes the latest research findings on high-speed railway track dynamics, made by the author and his research team over the past decade. It explores cutting-edge issues concerning the basic theory of high-speed railways, covering the dynamic theories, models, algorithms and engineering applications of the high-speed train and track coupling system. Presenting original concepts, systematic theories and advanced algorithms, the book places great emphasis on the precision and completeness of its content. The chapters are interrelated yet largely self-contained, allowing readers to either read through the book as a whole or focus on specific topics. It also combines theories with practice to effectively introduce readers to the latest research findings and developments in high-speed railway track dynamics. It offers a valuable resource for researchers, postgraduates and engineers in the fields of civil engineering, transportation, highway & railway engineering.

  7. Organizing for creativity, quality and speed in product creation processes

    NARCIS (Netherlands)

    Eijnatten, van F.M.; Simonse, W.L.

    1999-01-01

    Current research in industrial engineering and management sciences shows that organizational architectures are of critical importance for a better performance of product creation processes in terms of creativity, quality and speed. For many companies, streamlining those processes - including

  8. Endurance in speed skating

    NARCIS (Netherlands)

    Kuper, G.H.; Sterken, E.

    2002-01-01

    We analyse the development of world records speed skating from 1893 to 2000 for bothmen and women. The historical data show that it is likely that the relation betweenskating speed and distance of the various events is non-linear and converges to a limitvalue. We pay special attention to technical

  9. Endurance in speed skating

    NARCIS (Netherlands)

    Kuper, Gerard H.; Sterken, Elmer

    2001-01-01

    We analyse the development of world records speed skating from 1893 to 2000 for both men and women. The historical data show that it is likely that the relation between skating speed and distance of the various events is non-linear and converges to a limit value. We pay special attention to

  10. Experimental investigation of the effects of direct water injection parameters on engine performance in a six-stroke engine

    International Nuclear Information System (INIS)

    Arabaci, Emre; İçingür, Yakup; Solmaz, Hamit; Uyumaz, Ahmet; Yilmaz, Emre

    2015-01-01

    Highlights: • Exhaust gas temperature and specific fuel consumption decreased with six stroke engine. • Thermal efficiency increased with water injection. • NO emissions decreased with water injection as the temperature decreased at the end of cycle. • Injection timing should be advanced with the increase of engine speed. • HC and CO emissions decrease until 3000 rpm engine speed. - Abstract: In this study, the effects of water injection quantity and injection timing were investigated on engine performance and exhaust emissions in a six-stroke engine. For this purpose, a single cylinder, four-stroke gasoline engine was converted to six-stroke engine modifying a new cam mechanism and adapting the water injection system. The experiments were conducted at stoichometric air/fuel ratio (λ = 1) between 2250 and 3500 rpm engine speed at full load with liquid petroleum gas. Water injection was performed at three different stages as before top dead center, top dead center and after top dead center at constant injection duration and four different injection pressure 25, 50, 75 and 100 bar. The test results showed that exhaust gas temperature and specific fuel consumption decreased by about 7% and 9% respectively. In contrast, fuel consumption and power output increased 2% and 10% respectively with water injection. Thermal efficiency increased by about 8.72% with water injection. CO and HC emissions decreased 21.97% and 18.23% until 3000 rpm respectively. NO emissions decreased with water injection as the temperature decreased at the end of cycle. As a result, it was seen that engine performance improved when suitable injection timing and injected water quantity were selected due to effect of exhaust heat recovery with water injection

  11. Large aspect ratio tokamak study

    International Nuclear Information System (INIS)

    Reid, R.L.; Holmes, J.A.; Houlberg, W.A.; Peng, Y.K.M.; Strickler, D.J.; Brown, T.G.; Sardella, C.; Wiseman, G.W.

    1979-01-01

    The Large Aspect Ratio Tokamak Study (LARTS) investigated the potential for producing a viable long burn tokamak reactor through enhanced volt-second capability of the ohmic heating transformer by employing high aspect ratio designs. The plasma physics, engineering, and economic implications of high aspect ratio tokamaks were accessed in the context of extended burn operation. Plasma startup and burn parameters were addressed using a one-dimensional transport code. The pulsed electrical power requirements for the poloidal field system, which have a major impact on reactor economics, were minimized by optimizing the field in the ohmic heating coil and the wave shape of the ohmic heating discharge. A high aspect ratio reference reactor was chosen and configured

  12. Effectiveness of Motorcycle speed controlled by speed hump

    Directory of Open Access Journals (Sweden)

    Pornsiri Urapa

    2014-09-01

    Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

  13. 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.

  14. Investigating the effects of LPG on spark ignition engine combustion and performance

    International Nuclear Information System (INIS)

    Bayraktar, Hakan; Durgun, Orhan

    2005-01-01

    A quasi-dimensional spark ignition (SI) engine cycle model is used to predict the cycle, performance and exhaust emissions of an automotive engine for the cases of using gasoline and LPG. Governing equations of the mathematical model mainly consist of first order ordinary differential equations derived for cylinder pressure and temperature. Combustion is simulated as a turbulent flame propagation process and during this process, two different thermodynamic regions consisting of unburned gases and burned gases that are separated by the flame front are considered. A computer code for the cycle model has been prepared to perform numerical calculations over a range of engine speeds and fuel-air equivalence ratios. In the computations performed at different engine speeds, the same fuel-air equivalence ratios are selected for each fuel to make realistic comparisons from the fuel economy and fuel consumption points of view. Comparisons show that if LPG fueled SI engines are operated at the same conditions with those of gasoline fueled SI engines, significant improvements in exhaust emissions can be achieved. However, variations in various engine performance parameters and the effects on the engine structural elements are not promising

  15. Investigation of Water-spray Cooling of Turbine Blades in a Turbojet Engine

    Science.gov (United States)

    Freche, John C; Stelpflug, William J

    1953-01-01

    An analytical and experimental investigation was made with a J33-A-9 engine to determine the effectiveness of spray cooling as a means of increasing thrust by permitting engine operation at inlet-gas temperatures and speeds above rated. With the assumption of adequate spray cooling at a coolant-to-gas flow ratio of 3 percent, calculations for the sea-level static condition indicated a thrust may be achieved by engine operation at an inlet-gas temperature of 2000 degrees F and an overspeed of 10 percent. Of the water-injection configurations investigated experimentally, those located in the inner ring of the stator diaphragm provided the best cooling at rated engine speed.

  16. Combustion aided by a glow plug in diesel engines under cold idling conditions

    OpenAIRE

    Li, Qile

    2016-01-01

    Glow plugs are widely used to promote the desired cold start and post-cold start combustion characteristics of light duty diesel engines. The importance of the glow plug becomes more apparent when the compression ratio is low. An experimental investigation of combustion initiation and development aided by the glow plug has been carried out on a single cylinder HPCR DI diesel engine with a low compression ratio of 15.5:1. High speed imaging of combustion initiated by the glow plug in a combust...

  17. Speed, Acceleration, and Velocity: Level II, Unit 9, Lesson 1; Force, Mass, and Distance: Lesson 2; Types of Motion and Rest: Lesson 3; Electricity and Magnetism: Lesson 4; Electrical, Magnetic, and Gravitational Fields: Lesson 5; The Conservation and Conversion of Matter and Energy: Lesson 6; Simple Machines and Work: Lesson 7; Gas Laws: Lesson 8; Principles of Heat Engines: Lesson 9; Sound and Sound Waves: Lesson 10; Light Waves and Particles: Lesson 11; Program. A High.....

    Science.gov (United States)

    Manpower Administration (DOL), Washington, DC. Job Corps.

    This self-study program for high-school level contains lessons on: Speed, Acceleration, and Velocity; Force, Mass, and Distance; Types of Motion and Rest; Electricity and Magnetism; Electrical, Magnetic, and Gravitational Fields; The Conservation and Conversion of Matter and Energy; Simple Machines and Work; Gas Laws; Principles of Heat Engines;…

  18. Sound engineering for diesel engines; Sound Engineering an Dieselmotoren

    Energy Technology Data Exchange (ETDEWEB)

    Enderich, A.; Fischer, R. [MAHLE Filtersysteme GmbH, Stuttgart (Germany)

    2006-07-01

    The strong acceptance for vehicles powered by turbo-charged diesel engines encourages several manufacturers to think about sportive diesel concepts. The approach of suppressing unpleasant noise by the application of distinctive insulation steps is not adequate to satisfy sportive needs. The acoustics cannot follow the engine's performance. This report documents, that it is possible to give diesel-powered vehicles a sportive sound characteristic by using an advanced MAHLE motor-sound-system with a pressure-resistant membrane and an integrated load controlled flap. With this the specific acoustic disadvantages of the diesel engine, like the ''diesel knock'' or a rough engine running can be masked. However, by the application of a motor-sound-system you must not negate the original character of the diesel engine concept, but accentuate its strong torque characteristic in the middle engine speed range. (orig.)

  19. Cell formation effects on the burning speeds and flame front area of synthetic gas at high pressures and temperatures

    International Nuclear Information System (INIS)

    Askari, Omid; Elia, Mimmo; Ferrari, Matthew; Metghalchi, Hameed

    2017-01-01

    Highlights: • Effect of cell formation on burning speed and flame surface area is investigated. • A new developed non-dimensional number called cellularity factor is introduced. • Cellular burning speed and mass burning rate are calculated using differential based multi-shell model. • Flame instability is studied using thermo-diffusive and hydrodynamics effects. • Power law correlations are developed for cellular burning speeds and mass burning rates. - Abstract: Cellular burning speeds and mass burning rates of premixed syngas/oxidizer/diluent (H_2/CO/O_2/He) have been determined at high pressures and temperatures over a wide range of equivalence ratios which are at engine-relevant conditions. Working on high pressure combustion helps to reduce the pollution and increase the energy efficiency in combustion devices. The experimental facilities consisted of two spherical and cylindrical chambers. The spherical chamber, which can withstand high pressures up to 400 atm, was used to collect pressure rise data due to combustion, to calculate cellular burning speed and mass burning rate. For flame structure and instability analysis the cylindrical chamber was used to take pictures of propagating flame using a high speed CMOS camera and a schlieren photography system. A new differential based multi-shell model based on pressure rise data was used to determine the cellular burning speed and mass burning rate. In this paper, cellular burning speed and mass burning rate of H_2/CO/O_2/He mixture have been measured for a wide range of equivalence ratios from 0.6 to 2, temperatures from 400 to 750 K and pressures from 2 to 50 atm for three hydrogen concentrations of 5, 10 and 25% in the syngas. The power law correlations for cellular burning speed and mass burning rate were developed as a function of equivalence ratio, temperature and pressure. In this study a new developed parameter, called cellularity factor, which indicates the cell formation effect on flame

  20. The Crossing Speed of Elderly Pedestrians

    Directory of Open Access Journals (Sweden)

    Ana Trpković

    2017-04-01

    Full Text Available The population of elderly people is rapidly growing and in terms of safety, senior pedestrians represent one of the most vulnerable group. The pedestrian crossing speed is a significant input parameter in traffic engineering, which can have effect on pedestrians’ safety, especially of older population. The objective of this study was to determine the value of the crossing speed of elderly pedestrians (65+ for different types of urban crossings. The research was conducted at ten intersections in the city of Belgrade, Serbia, using the method of direct observation and a questionnaire for collecting data. The data were analysed in the statistical software package IBM SPSS Statistics. The results showed that elderly pedestrians walk slower and the crossing type significantly influenced the speed of older population. The order of crossing types in relation to the measured speed is ranked as follows, from the lowest to the highest speed value: unsignalized, signalized, signalized with pedestrian countdown display, signalized with pedestrian island and pedestrian countdown display and finally signalized crossing with pedestrian island. According to the questionnaire results, the elderly recognize the importance of implementing pedestrian counters. This indicates the necessity to provide safe street crossing for the elderly using the corresponding engineering measures.

  1. Traffic speed management

    Directory of Open Access Journals (Sweden)

    Subotić Jovana Lj.

    2014-01-01

    Full Text Available Speed, and vehicles themselves, affect the level of service and road safety, quality of life, noise from traffic, the environment, health, air pollution, emission of carbon dioxide, global warming, the economy and consumption of non-renewable energy such as oil. Therefore, the speed management of the traffic of multiple significance and that should be primarily to provide effective and economical conditions of the modern and preventive protection of human life as the greatest treasure and then the material resources. The way to accomplish this is by using various (different measures such as: appropriate planning and projecting roads and streets, speed control, the legislation, enforcement, campaigns, education, advanced technologies (ITS.

  2. Revolutionize Propulsion Test Facility High-Speed Video Imaging with Disruptive Computational Photography Enabling Technology

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced rocket propulsion testing requires high-speed video recording that can capture essential information for NASA during rocket engine flight certification...

  3. 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)

  4. QCGAT aircraft/engine design for reduced noise and emissions

    Science.gov (United States)

    Lanson, L.; Terrill, K. M.

    1980-01-01

    The high bypass ratio QCGAT engine played an important role in shaping the aircraft design. The aircraft which evolved is a sleek, advanced design, six-place aircraft with 3538 kg (7,800 lb) maximum gross weight. It offers a 2778 kilometer (1500 nautical mile) range with cruise speed of 0.5 Mach number and will take-off and land on the vast majority of general aviation airfields. Advanced features include broad application of composite materials and a supercritical wing design with winglets. Full-span fowler flaps were introduced to improve landing capability. Engines are fuselage-mounted with inlets over the wing to provide shielding of fan noise by the wing surfaces. The design objectives, noise, and emission considerations, engine cycle and engine description are discussed as well as specific design features.

  5. Combustion of jojoba methyl ester in an indirect injection diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Selim, M.Y.E. [United Arab Emirates University, Al-Ain (United Arab Emirates). Mechanical Engineering Dept.; Radwan, M.S.; Elfeky, S.M.S. [Helwan University, Cairo (Egypt). Mechanical Power Engineering Dept.

    2003-07-01

    An experimental investigation has been carried out to examine for the first time the performance and combustion noise of an indirect injection diesel engine running with new fuel derived from pure jojoba oil, jojoba methyl ester, and its blends with gas oil. A Ricardo E6 compression swirl diesel engine was fully instrumented for the measurement of combustion pressure and its rise rate and other operating parameters. Test parameters included the percentage of jojoba methyl ester in the blend, engine speed, load, injection timing and engine compression ratio. Results showed that the new fuel derived from jojoba is generally comparable and a good replacement to gas oil in diesel engine at most engine operating conditions, in terms of performance parameters and combustion noise produced. (author)

  6. Baseline performance and emissions data for a single-cylinder, direct-injected diesel engine

    Science.gov (United States)

    Dezelick, R. A.; Mcfadden, J. J.; Ream, L. W.; Barrows, R. F.

    1983-01-01

    Comprehensive fuel consumption, mean effective cylinder pressure, and emission test results for a supercharged, single-cylinder, direct-injected, four-stroke-cycle, diesel test engine are documented. Inlet air-to-exhaust pressure ratios were varied from 1.25 to 3.35 in order to establish the potential effects of turbocharging techniques on engine performance. Inlet air temperatures and pressures were adjusted from 34 to 107 C and from 193 to 414 kPa to determine the effects on engine performance and emissions. Engine output ranged from 300 to 2100 kPa (brake mean effective pressure) in the speed range of 1000 to 3000 rpm. Gaseous and particulate emission rates were measured. Real-time values of engine friction and pumping loop losses were measured independently and compared with motored engine values.

  7. Wind_Speeds_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  8. High speed data acquisition

    International Nuclear Information System (INIS)

    Cooper, P.S.

    1997-07-01

    A general introduction to high speed data acquisition system techniques in modern particle physics experiments is given. Examples are drawn from the SELEX(E78 1) high statistics charmed baryon production and decay experiment now taking data at Fermilab

  9. Modeling of hybrid vehicle fuel economy and fuel engine efficiency

    Science.gov (United States)

    Wu, Wei

    "Near-CV" (i.e., near-conventional vehicle) hybrid vehicles, with an internal combustion engine, and a supplementary storage with low-weight, low-energy but high-power capacity, are analyzed. This design avoids the shortcoming of the "near-EV" and the "dual-mode" hybrid vehicles that need a large energy storage system (in terms of energy capacity and weight). The small storage is used to optimize engine energy management and can provide power when needed. The energy advantage of the "near-CV" design is to reduce reliance on the engine at low power, to enable regenerative braking, and to provide good performance with a small engine. The fuel consumption of internal combustion engines, which might be applied to hybrid vehicles, is analyzed by building simple analytical models that reflect the engines' energy loss characteristics. Both diesel and gasoline engines are modeled. The simple analytical models describe engine fuel consumption at any speed and load point by describing the engine's indicated efficiency and friction. The engine's indicated efficiency and heat loss are described in terms of several easy-to-obtain engine parameters, e.g., compression ratio, displacement, bore and stroke. Engine friction is described in terms of parameters obtained by fitting available fuel measurements on several diesel and spark-ignition engines. The engine models developed are shown to conform closely to experimental fuel consumption and motored friction data. A model of the energy use of "near-CV" hybrid vehicles with different storage mechanism is created, based on simple algebraic description of the components. With powertrain downsizing and hybridization, a "near-CV" hybrid vehicle can obtain a factor of approximately two in overall fuel efficiency (mpg) improvement, without considering reductions in the vehicle load.

  10. Experimental study of gas engine driven air to water heat pump in cooling mode

    International Nuclear Information System (INIS)

    Elgendy, E.; Schmidt, J.

    2010-01-01

    Nowadays a sustainable development for more efficient use of energy and protection of the environment is of increasing importance. Gas engine heat pumps represent one of the most practicable solutions which offer high energy efficiency and environmentally friendly for heating and cooling applications. In this paper, the performance characteristics of gas engine driven heat pump used in water cooling were investigated experimentally without engine heat recovery. The effects of several important factors (evaporator water inlet temperature, evaporator water volume flow rate, ambient air temperature, and engine speed) on the performance of gas engine driven heat pump were studied in a wide range of operating conditions. The results showed that primary energy ratio of the system increased by 22.5% as evaporator water inlet temperature increased from 13 o C to 24 o C. On the other hand, varying of engine speed from 1300 rpm to 1750 rpm led to decrease in system primary energy ratio by 13%. Maximum primary energy ratio has been estimated with a value of two over a wide range of operating conditions.

  11. High speed heterostructure devices

    CERN Document Server

    Beer, Albert C; Willardson, R K; Kiehl, Richard A; Sollner, T C L Gerhard

    1994-01-01

    Volume 41 includes an in-depth review of the most important, high-speed switches made with heterojunction technology. This volume is aimed at the graduate student or working researcher who needs a broad overview andan introduction to current literature. Key Features * The first complete review of InP-based HFETs and complementary HFETs, which promise very low power and high speed * Offers a complete, three-chapter review of resonant tunneling * Provides an emphasis on circuits as well as devices.

  12. High Specific Stiffness Shafts and Advanced Bearing Coatings for Gas Turbine Engines Final Report CRADA No. TC-1089-95

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, Troy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chin, Herbert [United Technologies Corporation, East Hartford, CT (United States)

    2017-11-09

    At the time of the CRADA, the largest in-service gas-turbine aircraft engines strove for increased thrust and power density to meet the requirements for take-off thrust, given the increase in take-off gross weight (TOGW) associated with longer range transport requirements. The trend in modem turbo shaft engines was toward turbine shafts with higher and higher length-to-diameter ratios, which reduced the shaft critical speed. Using co nventional shaft materials, this lead to shafts that needed to operate near or above sensitive shaft bending critical speeds, therefore requiring multiple bearings and/ or multiple squeeze-film dampers to control the dynamic response. Using new materials and d esign concepts this project demonstrated the use of new shaft materials which could provide increased shaft speed range above existing maximum engine speeds without encountering a critic al speed event and high vector deflections. This increased main shaft speed also resulted in decreased bearing life associated with lower heat dissipation and higher centrifugal forces. Thus, a limited effort was devoted to feasibility of higher performance bearing coatings to mitigate the speed effects.

  13. An experimental study on the effect of using gas-to-liquid (GTL fuel on diesel engine performance and emissions

    Directory of Open Access Journals (Sweden)

    M.A. Bassiony

    2016-09-01

    Full Text Available Gas to Liquid (GTL fuel is considered one of the most propitious clean alternative fuels for the diesel engines. The aim of this study was to experimentally compare the performance and emissions of a diesel engine fueled by GTL fuel, diesel, and a blend of GTL and diesel fuels with a mixing ratio of 1:1 by volume (G50 at various engine load and speed conditions. Although using the GTL and G50 fuels decreased slightly the engine maximum power compared to the diesel fuel, both the engine brake thermal efficiency and engine brake specific fuel consumption were improved. In addition, using the GTL and G50 fuels as alternatives to the diesel resulted in a significant decrease in engine CO, NOx, and SO2 emissions.

  14. Analysis of an Increase in the Efficiency of a Spark Ignition Engine Through the Application of an Automotive Thermoelectric Generator

    Science.gov (United States)

    Merkisz, Jerzy; Fuc, Pawel; Lijewski, Piotr; Ziolkowski, Andrzej; Galant, Marta; Siedlecki, Maciej

    2016-08-01

    We have analyzed the increase of the overall efficiency of a spark ignition engine through energy recovery following the application of an automotive thermoelectric generator (ATEG) of our own design. The design of the generator was developed following emission investigations during vehicle driving under city traffic conditions. The measurement points were defined by actual operation conditions (engine speed and load), subsequently reproduced on an engine dynamometer. Both the vehicle used in the on-road tests and the engine dynamometer were fit with the same, downsized spark ignition engine (with high effective power-to-displacement ratio). The thermodynamic parameters of the exhaust gases (temperature and exhaust gas mass flow) were measured on the engine testbed, along with the fuel consumption and electric current generated by the thermoelectric modules. On this basis, the power of the ATEG and its impact on overall engine efficiency were determined.

  15. Basic tuning of hydrogen powered car and artificial intelligent prediction of hydrogen engine characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tien [School of Engineering, University of Tasmania, GPO Box 252-65, Hobart, Tasmania, 7001 (Australia); Karri, Vishy [Australian College of Kuwait, P.O. Box 1411, Safat 13015 (Kuwait)

    2010-09-15

    Many studies of renewable energy have shown hydrogen is one of the major green energy in the future. This has lead to the development of many automotive application of using hydrogen as a fuel especially in internal combustion engine. Nonetheless, there has been a slow growth and less knowledge details in building up the prototype and control methodology of the hydrogen internal combustion engine. In this paper, The Toyota Corolla 4 cylinder, 1.8l engine running on petrol was systematically modified in such a way that it could be operated on either gasoline or hydrogen at the choice of the driver. Within the scope of this project, several ancillary instruments such as a new inlet manifold, hydrogen fuel injection, storage system and leak detection safety system were implemented. Attention is directed towards special characteristics related to the basic tuning of hydrogen engine such as: air to fuel ratio operating conditions, ignition timing and injection timing in terms of different engine speed and throttle position. Based on the experimental data, a suite of neural network models were tested to accurately predict the effect of different engine operating conditions (speed and throttle position) on the hydrogen powered car engine characteristics. Predictions were found to be {+-}3% to the experimental values for all of case studies. This work provided better understanding of the effect of hydrogen engine characteristic parameters on different engine operating conditions. (author)

  16. Comments on ‘Temporal significant wave height estimation from wind speed by perceptron Kalman filtering’ by A. Altunkaynak and M. Ozger, Ocean Engineering, Vol. 31(10); 2004,1245-1255

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    wind speed. Interestingly the PKF model is a two layered network (input and output) without hidden layer. Also it is a fact that numerical or physical models have restrictions by certain assumptions and conditions, whereas artificial neural network... is shown by Tsai et al (2002). They have carried out forecasting of significant wave heights and periods at a desired location directly from the observed wave records using a supervised artificial neural network with error back-propagation procedures...

  17. Laboratory Test of Reciprocating Internal Combustion Engines

    Science.gov (United States)

    2016-02-04

    Control Module (ECM) torque horsepower engine speed boost turbocharger throttle injector power curve...13 2.4 Calibration ............................................................................. 14...Control Units (ECU). Originally, diesel engines were naturally aspirated, but most have evolved to include forced induction devices (turbochargers

  18. Primary response of high-aspect-ratio thermoresistive sensors

    Science.gov (United States)

    Majlesein, H. R.; Mitchell, D. L.; Bhattacharya, Pradeep K.; Singh, A.; Anderson, James A.

    1997-07-01

    There is a growing need for sensors in monitoring performance in modern quality products such as in electronics to monitor heat build up, substrate delaminations, and thermal runaway. In processing instruments, intelligent sensors are needed to measure deposited layer thickness and resistivities for process control, and in environmental electrical enclosures, they are used for climate monitoring and control. A yaw sensor for skid prevention utilizes very fine moveable components, and an automobile engine controller blends a microprocessor and sensor on the same chip. An Active-Pixel Image Sensor is integrated with a digital readout circuit to perform most of the functions in a video camera. Magnetostrictive transducers sense and damp vibrations. Improved acoustic sensors will be used in flow detection of air and other fluids, even at subsonic speeds. Optoelectronic sensor systems are being developed for installation on rocket engines to monitor exhaust gases for signs of wear in the engines. With new freon-free coolants being available the problems of A/C system corrosion have gone up in automobiles and need to be monitored more frequently. Defense cutbacks compel the storage of hardware in safe-custody for an indeterminate period of time, and this makes monitoring more essential. Just-in-time customized manufacturing in modern industries also needs dramatic adjustment in productivity of various selected items, leaving some manufacturing equipment idle for a long time, and therefore, it will be prone to more corrosion, and corrosion sensors are needed. In the medical device industry, development of implantable medical devices using both potentiometric and amperometric determination of parameters has, until now, been used with insufficient micro miniaturization, and thus, requires surgical implantation. In many applications, high-aspect- ratio devices, made possible by the use of synchrotron radiation lithography, allow more useful devices to be produced. High-aspect-ratio

  19. An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

    Science.gov (United States)

    Bruckner, Robert J.

    2010-01-01

    Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

  20. Everyone Deserves a Speeding Ticket.

    Science.gov (United States)

    Burris, Harold

    1993-01-01

    Presents a first day physics activity having students determine the fine for a speeding ticket if the speeds considered include the earth's rotation and revolution speed, and the movement through the galaxy. (MDH)

  1. Continuous QKD and high speed data encryption

    Science.gov (United States)

    Zbinden, Hugo; Walenta, Nino; Guinnard, Olivier; Houlmann, Raphael; Wen, Charles Lim Ci; Korzh, Boris; Lunghi, Tommaso; Gisin, Nicolas; Burg, Andreas; Constantin, Jeremy; Legré, Matthieu; Trinkler, Patrick; Caselunghe, Dario; Kulesza, Natalia; Trolliet, Gregory; Vannel, Fabien; Junod, Pascal; Auberson, Olivier; Graf, Yoan; Curchod, Gilles; Habegger, Gilles; Messerli, Etienne; Portmann, Christopher; Henzen, Luca; Keller, Christoph; Pendl, Christian; Mühlberghuber, Michael; Roth, Christoph; Felber, Norbert; Gürkaynak, Frank; Schöni, Daniel; Muheim, Beat

    2013-10-01

    We present the results of a Swiss project dedicated to the development of high speed quantum key distribution and data encryption. The QKD engine features fully automated key exchange, hardware key distillation based on finite key security analysis, efficient authentication and wavelength division multiplexing of the quantum and the classical channel and one-time pas encryption. The encryption device allows authenticated symmetric key encryption (e.g AES) at rates of up to 100 Gb/s. A new quantum key can uploaded up to 1000 times second from the QKD engine.

  2. Development of an engine control system using city gas and biogas fuel mixture

    International Nuclear Information System (INIS)

    Yamasaki, Yudai; Kanno, Masanobu; Suzuki, Yoshitaka; Kaneko, Shigehiko

    2013-01-01

    Highlights: ► The gas engine control system was developed using both city gas and biogas flexibly. ► The developed control system corporates with an original controller. ► The target value of O 2 emission is decided by Wobbe index of mixture fuel and load. ► The controller achieved stable operation for fuel mix ratio and load changing. -- Abstract: In this paper, a gas engine system capable of stable operation at any mix ratio of city gas 13A and biogas was developed. The gas engine system consists of a spark-ignition gas engine, an additional electric throttle valve for fuel and our own control algorithm. The engine is a 3-cylinder 1.6-l engine that was originally used for co-generation, and the fuel throttle valve was added to respond to different fuel compositions. The control algorithm was also designed to adjust the fuel and air ratio to attain a higher generation efficiency and lower NOx emission with different mix ratios of city gas 13A, biogas and load. Before developing the controller, the effect of the mix ratio on generation efficiency and NOx emission was investigated under various load conditions. The following summarizes the experimental results: a control algorithm using the Wobbe index for mixed fuels was formulated; this index determines the target fuel-to-air ratio. Next, operation tests were performed under varying fuel mix ratios and loads by applying the control algorithm to the gas engine. The target engine rotational speed and exhaust O 2 concentration was realized in 5 s when the biogas fraction varied from 20% to 40% and from 70% to 40%. When the load was also varied from 9.4 kW to 0.5 kW and from 0.5 kW to 9.4 kW at a constant rate, the rotational speed and exhaust O 2 concentration achieved the target values in 20 s. Under both transient operation conditions, the engine system met the NOx emission requirement, and the results indicate that the simple hardware modification to a conventional gas engine and our original control

  3. Parametric study of power turbine for diesel engine waste heat recovery

    International Nuclear Information System (INIS)

    Zhao, Rongchao; Zhuge, Weilin; Zhang, Yangjun; Yin, Yong; Chen, Zhen; Li, Zhigang

    2014-01-01

    Turbocompounding is a promising technology to recover waste heat from the exhaust and reduce fuel consumption for internal combustion engine. The design of a power turbine plays a key role in turbocompound engine performance. This paper presents a set of parametric studies of power turbine performed on a turbocompound diesel engine by means of turbine through-flow model developed by the authors. This simulation model was verified and validated using engine performance test data and achieved reasonable accuracy. The paper first analyzed the influence of three key geometrical parameters (blade height, blade radius and nozzle exit blade angle) on turbine expansion ratio and engine fuel consumptions. After that, the impacts of the geometrical parameters on power distribution, air mass flow rate and exhaust temperature were analyzed. Results showed that these parameters had significant effects on engine BSFC and power. At high engine speeds, there existed an optimum value of geometry parameter to obtain the lowest BSFC. At low engine speeds, the engine BSFC kept increasing or decreasing continuously as the geometry parameters changed. Research also found that the engine BSFC was most sensitive to the nozzle exit blade angle, which should be considered carefully during the design process. This paper provides a useful method for matching and designing of a power turbine for turbocompound engine. - Highlights: •Through-flow model of axial-flow power turbine for turbocompound engine was established. •Turbocompound engine performance test was carried out to validate the cycle simulation model. •Influences of power turbine geometry parameters on engine BSFC and power were presented

  4. Slower speed and stronger coupling: adaptive mechanisms of chaos synchronization.

    Science.gov (United States)

    Wang, Xiao Fan

    2002-06-01

    We show that two initially weakly coupled chaotic systems can achieve synchronization by adaptively reducing their speed and/or enhancing the coupling strength. Explicit adaptive algorithms for speed reduction and coupling enhancement are provided. We apply these algorithms to the synchronization of two coupled Lorenz systems. It is found that after a long-time adaptive process, the two coupled chaotic systems can achieve synchronization with almost the minimum required coupling-speed ratio.

  5. 33 CFR 84.24 - High-speed craft.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false High-speed craft. 84.24 Section... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.24 High-speed craft. (a) The masthead light of high-speed craft with a length to breadth ratio of less than 3.0 may be placed at a...

  6. Development of an empirical correlation for combustion durations in spark ignition engines

    International Nuclear Information System (INIS)

    Bayraktar, Hakan; Durgun, Orhan

    2004-01-01

    Development of an empirical correlation for combustion duration is presented. For this purpose, the effects of variations in compression ratio engine speed, fuel/air equivalence ratio and spark advance on combustion duration have been determined by means of a quasi-dimensional SI engine cycle model previously developed by the authors. Burn durations at several engine operating conditions were calculated from the turbulent combustion model. Variations of combustion duration with each operating parameter obtained from the theoretical results were expressed by second degree polynomial functions. By using these functions, a general empirical correlation for the burn duration has been developed. In this correlation, the effects of engine operating parameters on combustion duration were taken into account. Combustion durations predicted by means of this correlation are in good agreement with those obtained from experimental studies and a detailed combustion model

  7. 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.

  8. Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics. 5; Operational Characteristics

    Science.gov (United States)

    Golladay, Richard L.; Gendler, Stanley L.

    1947-01-01

    An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilli.ng, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted. Maximum engine speed was obtainable at all altitudes and airspeeds wi th each fuel-control system investigated. The minimum idling speed was raised by increases in altitude and airspeed. The lowest minimum stable speeds were obtained with the standard configuration using 40-gallon nozzles with individual metering plugs. The engine was started normally at altitudes as high as 20,000 feet with all of the fuel systems and ignition combinations except one. Ignition at 70,000 feet was difficult and, although successful ignition occurred, acceleration was slow and usually characterized by excessive tail-pipe temperature. During windmilling investigations of the engine equipped with the standard fuel system, the engine could not be started at ram-pressure ratios of 1.1 to 1.7 at altitudes of 10,000, 20,000 and 30,000 feet. When equipped with the production barometric and Monarch 40-gallon nozzles, the engine accelerated in 12 seconds from an engine speed of 6000 rpm to 11,000 rpm at 20,000 feet and an average tail-pipe temperature of 11000 F. At the same altitude and temperature, all the engine configurations had approximately the same rate of acceleration. The Woodward governor produced the safest accelerations, inasmuch as it could be adjusted to automatically prevent acceleration blow out. The engine speed was

  9. PERSONALITY AND SPEEDING

    Directory of Open Access Journals (Sweden)

    Richard TAY

    2003-01-01

    Full Text Available While there has been extensive research on the effect of sensation seeking on risky driving, relatively little research has been conducted on Type-A personality. The motivations for speeding are likely to be different for each group and these differences have important implications for the design, implementation and expected efficacy of road safety countermeasures. This paper examines the influence of sensation seeking and Type-A behavior pattern on speeding behaviour. A sample of 139 staff and students in an Australian university were surveyed in July 2001 to gather information on their gender, age, personality and self-reported speeding behaviour. The data were analysed using correlations and analysis of variance procedures. Finally, some implications for road safety are discussed.

  10. Variable speed control for Vertical Axis Wind Turbine

    DEFF Research Database (Denmark)

    Galinos, Christos; Larsen, Torben J.

    A robust variable speed control for vertical axis wind turbine applications is implemented. It is a PI rotor speed controller based on an induction generator model operated at variable frequency. The generator dynamics are approximated by a first order differential equation with a prescribed slip....... In order to allow variability in the rotor speed an inverter is assumed which changes the nominal generator speed. Below rated power the optimum tip speed ratio is tracked, while above the power is constrained to rated. The wind speed which is needed in the control it is considered as a known signal...... the Inflow project. The investigation of the VAWT performance under different control parameters such as the PI gains has been performed by Christos Galinos. Deterministic and turbulent wind speed steps of 2 m/s from 6 m/s to 24 m/s and back to 12 m/s are applied. The controller gives smooth transient...

  11. Speed-calming measures and their Effect on driving speed

    DEFF Research Database (Denmark)

    Agerholm, Niels; Knudsen, Daniel; Variyeswaran, Kajan

    2017-01-01

    Highlights •Speed humps and chicanes are widespread speed-calming measures. •Humps and chicanes have virtually the same reducing effect on mean speed. •Chicanes reduce speed variation less than humps and might therefore be a less safe measure....

  12. 14 CFR 23.361 - Engine torque.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine torque. 23.361 Section 23.361... Engine torque. (a) Each engine mount and its supporting structure must be designed for the effects of— (1) A limit engine torque corresponding to takeoff power and propeller speed acting simultaneously with...

  13. Effect of engine parameters and gaseous fuel type on the cyclic variability of dual fuel engines

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed Y.E. Selim [United Arab Emirates University, Al-Ain (United Arab Emirates). Mechanical Engineering Department, Faculty of Engineering

    2005-05-01

    This paper presents an analysis of the cycle-to-cycle combustion variation as reflected in the combustion pressure data of a single cylinder, naturally aspirated, four stroke, Ricardo E6 engine converted to run as dual fuel engine on diesel and gaseous fuel of LPG or methane. A measuring set-up consisting of a piezo-electric pressure transducer with charge amplifier and fast data acquisition card installed on an IBM microcomputer was used to gather the data of up to 1200 consecutive combustion cycles of the cylinder under various combination of engine operating and design parameters. These parameters included type of gaseous fuel, engine load, compression ratio, pilot fuel injection timing, pilot fuel mass, and engine speed. The data for each operating conditions were analyzed for the maximum pressure, the maximum rate of pressure rise representing the combustion noise, and indicated mean effective pressure. The cycle-to-cycle variation is expressed as the mean value, standard deviation, and coefficient of variation of these three parameters. It was found that the type of gaseous fuel and engine operating and design parameters affected the combustion noise and its cyclic variation and these effects have been presented. 21 refs., 6 figs., 1 tab.

  14. Speed control of diesel generator sets

    International Nuclear Information System (INIS)

    Jenzer, J.

    1989-01-01

    In some marine and stationary power plants, it is often of interest to be able to give some information about the dynamic behaviour of the engine when it is loaded according to a given programme: How well it reacts to the application of a step load and to a load rejection. What is the best speed governor type and its optimum parameter adjustment in order to satisfy the requested specification of maximum speed engine deviation and recovery time. How great is the influence of turbocharger options such as jet assist or waste gate on the dynamic behaviour of the plant. Such kinds of questions occur for all stand-by power stations and in marine installations where the engine is submitted to very large load variations in the form of steps, ramps or any other load programme. The computer program GENERAT fully fulfils the aims described above. The comparison of measurements and simulation is good enough to allow us to use simulation as a means of predicting the dynamic behaviour of stationary power plant with four-stroke engines submitted to a given load programme. This program allows us also to determine the optimum generator inertia and to find the optimum governor parameters. The next step of development will be to model the turbocharger and supercharging method for two-stroke engines and some new digital speed controls and to rewrite the program with the help of the simulation package ACSL. This last point presents some advantages, as for example in large reduction of program maintenance and higher flexibility

  15. Effect of Injector Nozzle Holes on Diesel Engine Performance

    OpenAIRE

    Semin,; Yusof, Mohd Yuzri Mohd; Arof, Aminuddin Md; Shaharudin, Daneil Tomo; Ismail, Abdul Rahim

    2010-01-01

    All of the injector nozzle holes have examined and the results are shown that the seven holes nozzle have provided the best burning result for the fuel in-cylinder burned in any different engine speeds and the best burning is in low speed engine. In engine performance effect, all of the nozzles have examined and the five holes nozzle provided the best result in indicted power, indicated torque and ISFC in any different engine speeds.

  16. Self-Powered, High-Speed and Visible-Near Infrared Response of MoO(3-x)/n-Si Heterojunction Photodetector with Enhanced Performance by Interfacial Engineering.

    Science.gov (United States)

    Zhao, Chuanxi; Liang, Zhimin; Su, Mingze; Liu, Pengyi; Mai, Wenjie; Xie, Weiguang

    2015-11-25

    Photodetectors with a wide spectrum response are important components for sensing, imaging, and other optoelectronic applications. A molybdenum oxide (MoO(3-x))/Si heterojunction has been applied as solar cells with great success, but its potential in photodetectors has not been explored yet. Herein, a self-powered, high-speed heterojunction photodetector fabricated by coating an n-type Si hierarchical structure with an ultrathin hole-selective layer of molybdenum oxide (MoO(3-x)) is first investigated. Excellent and stable photoresponse performance is obtained by using a methyl group passivated interface. The heterojunction photodetector demonstrated high sensitivity to a wide spectrum from 300 to 1100 nm. The self-powered photodetector shows a high detectivity of (∼6.29 × 10(12) cmHz(1/2) W(-1)) and fast response time (1.0 μs). The excellent photodetecting performance is attributed to the enhanced interfacial barrier height and three-dimensional geometry of Si nanostructures, which is beneficial for efficient photocarrier collection and transportation. Finally, our devices show excellent long-term stability in air for 6 months with negligible performance degradation. The thermal evaporation method for large-scale fabrication of MoO(3-x)/n-Si photodetectors makes it suitable for self-powered, multispectral, and high-speed response photodetecting applications.

  17. Intelligent Speed Assistance (ISA).

    NARCIS (Netherlands)

    2015-01-01

    Intelligent Speed Assistance (ISA) has been a promising type of advanced driver support system for some decades. From a technical point of view, large scale ISA implementation is possible in the short term. The different types of ISA are expected to have different effects on behaviour and traffic

  18. Speed mathematics simplified

    CERN Document Server

    Stoddard, Edward

    1994-01-01

    Entertaining, easy-to-follow suggestions for developing greater speed and accuracy in doing mathematical calculations. Surefire methods for multiplying without carrying, dividing with half the pencil work of long division, plus advice on how to add and subtract rapidly, master fractions, work quickly with decimals, handle percentages, and much more.

  19. High speed metal removal

    Science.gov (United States)

    Pugh, R. F.; Pohl, R. F.

    1982-10-01

    Four types of steel (AISI 1340, 4140, 4340, and HF-1) which are commonly used in large caliber projectile manufacture were machined at different hardness ranges representing the as-forged and the heat treated condition with various ceramic tools using ceramic coated tungsten carbide as a reference. Results show that machining speeds can be increased significantly using present available tooling.

  20. Variable speed generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    With the deregulation of electrical energy production and distribution, says Boldea (Polytechnical Institute, Timisoara, Romania) producers are looking for ways to tailor their electricity for different markets. Variable-speed electric generators are serving that purpose, up to the 400 megavolt ampere unit size, in Japan since 1996 and Germany sinc

  1. Beneath the Wheel - Greenwood Engineering

    DEFF Research Database (Denmark)

    Dias, Kealey; Gravesen, Jens; Hjorth, Poul G.

    This is the report from the 54th European Study Group wiht Industry of the Greenwood Engineering problem. We model pavement response to both a point and distributed loads and compare with data from Greenwood's High Speed Deflectograph Measurements.......This is the report from the 54th European Study Group wiht Industry of the Greenwood Engineering problem. We model pavement response to both a point and distributed loads and compare with data from Greenwood's High Speed Deflectograph Measurements....

  2. Exergetic Evaluation of Speed and Load Effects in Spark Ignition Engines Évaluation exergétique des effets de la vitesse et de la charge dans les moteurs àallumage par étincelle

    OpenAIRE

    Sezer I.; Bilgin A.

    2012-01-01

    This study investigates the effects of various operating conditions in spark ignition engines via an exergy analysis. A thermodynamic cycle model including compression, combustion and expansion processes was used for investigation. Induction and exhaust processes were computed with a simple approximation method. The principles of the second law were applied to the cycle model to perform the exergy analysis. Exergetic variables, i.e., the exergy transfers with heat and work, irreversibili...

  3. Cycle Engine Modelling Of Spark Ignition Engine Processes during Wide-Open Throttle (WOT) Engine Operation Running By Gasoline Fuel

    International Nuclear Information System (INIS)

    Rahim, M F Abdul; Rahman, M M; Bakar, R A

    2012-01-01

    One-dimensional engine model is developed to simulate spark ignition engine processes in a 4-stroke, 4 cylinders gasoline engine. Physically, the baseline engine is inline cylinder engine with 3-valves per cylinder. Currently, the engine's mixture is formed by external mixture formation using piston-type carburettor. The model of the engine is based on one-dimensional equation of the gas exchange process, isentropic compression and expansion, progressive engine combustion process, and accounting for the heat transfer and frictional losses as well as the effect of valves overlapping. The model is tested for 2000, 3000 and 4000 rpm of engine speed and validated using experimental engine data. Results showed that the engine is able to simulate engine's combustion process and produce reasonable prediction. However, by comparing with experimental data, major discrepancy is noticeable especially on the 2000 and 4000 rpm prediction. At low and high engine speed, simulated cylinder pressures tend to under predict the measured data. Whereas the cylinder temperatures always tend to over predict the measured data at all engine speed. The most accurate prediction is obtained at medium engine speed of 3000 rpm. Appropriate wall heat transfer setup is vital for more precise calculation of cylinder pressure and temperature. More heat loss to the wall can lower cylinder temperature. On the hand, more heat converted to the useful work mean an increase in cylinder pressure. Thus, instead of wall heat transfer setup, the Wiebe combustion parameters are needed to be carefully evaluated for better results.

  4. Engine Power Turbine and Propulsion Pod Arrangement Study

    Science.gov (United States)

    Robuck, Mark; Zhang, Yiyi

    2014-01-01

    A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing

  5. Experimental investigations of butanol-gasoline blends effects on the combustion process in a SI engine

    Energy Technology Data Exchange (ETDEWEB)

    Merola, Simona Silvia; Tornatore, Cinzia; Machitto, Luca; Valentino, Gerardo; Corcione, Felice Esposito [Istituto Motori-CNR, Naples (Italy)

    2012-07-01

    Fuel blend of alcohol and conventional hydrocarbon fuels for a spark-ignition engine can increase the fuel octane rating and the power for a given engine displacement and compression ratio. In this work, the influence of butanol addition to gasoline in a port fuel-injection, spark ignition engine was investigated. The experiments were realized in a single cylinder ported fuel injection SI engine with an external boosting device. The optical accessible engine was equipped with the head of commercial SI turbocharged engine with the same geometrical specifications (bore, stroke, compression ratio) as the research engine. The effect on the spark ignition combustion process of 20% and 40% of n-butanol blended in volume with pure gasoline was investigated through cycle resolved visualization. The engine worked at low speed, medium boosting and wide open throttle. Fuel injections both in closed valve and open valve conditions were considered. Comparisons between the parameters related to the flame luminosity and the pressure signals were performed. Butanol blends allowed working in more advanced spark timing without knocking occurrence. The duration of injection for Butanol blends was increased to obtain stoichiometric mixture. In open valve injection condition, the fuel deposits on intake manifold and piston surfaces decreased, allowing a reduction in fuel consumption. BU40 granted the performance levels of gasoline and in open valve injection allowed to minimize the abnormal combustion effects including the emission of ultrafine carbonaceous particles at the exhaust. In-cylinder investigations were correlated to engine out emissions. (orig.)

  6. 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.

  7. Financial Key Ratios

    OpenAIRE

    Tănase Alin-Eliodor

    2014-01-01

    This article focuses on computing techniques starting from trial balance data regarding financial key ratios. There are presented activity, liquidity, solvency and profitability financial key ratios. It is presented a computing methodology in three steps based on a trial balance.

  8. Computer aided photographic engineering

    Science.gov (United States)

    Hixson, Jeffrey A.; Rieckhoff, Tom

    1988-01-01

    High speed photography is an excellent source of engineering data but only provides a two-dimensional representation of a three-dimensional event. Multiple cameras can be used to provide data for the third dimension but camera locations are not always available. A solution to this problem is to overlay three-dimensional CAD/CAM models of the hardware being tested onto a film or photographic image, allowing the engineer to measure surface distances, relative motions between components, and surface variations.

  9. Engine Cold Start

    Science.gov (United States)

    2015-09-01

    matching pre- calibrated amplifier • BEI Shaft Encoder (0.2 CAD) • Wolff Instrumented Injector The high speed data was recorded and post-processed by...14. ABSTRACT These fuels were used for testing a GEP 6.5L turbocharged V-8 diesel engine operation in a cold box. This engine architecture is...Z39.18 UNCLASSIFIED UNCLASSIFIED v EXECUTIVE SUMMARY A fuel’s cetane number is very important for the operation of modern diesel

  10. Performance of single cylinder, direct injection Diesel engine using water fuel emulsions

    International Nuclear Information System (INIS)

    Abu-Zaid, M.

    2004-01-01

    A single cylinder Diesel engine study of water-in-Diesel emulsions was conducted to investigate the effect of water emulsification on the engine performance and gases exhaust temperature. Emulsified Diesel fuels of 0, 5, 10, 15 and 20 water/Diesel ratios by volume, were used in a single cylinder, direct injection Diesel engine, operating at 1200-3300 rpm. The results indicate that the addition of water in the form of emulsion improves combustion efficiency. The engine torque, power and brake thermal efficiency increase as the water percentage in the emulsion increases. The average increase in the brake thermal efficiency for 20% water emulsion is approximately 3.5% over the use of Diesel for the engine speed range studied. The proper brake specific fuel consumption and gases exhaust temperature decrease as the percentage of water in the emulsion increases

  11. A Modular Aero-Propulsion System Simulation of a Large Commercial Aircraft Engine

    Science.gov (United States)

    DeCastro, Jonathan A.; Litt, Jonathan S.; Frederick, Dean K.

    2008-01-01

    A simulation of a commercial engine has been developed in a graphical environment to meet the increasing need across the controls and health management community for a common research and development platform. This paper describes the Commercial Modular Aero Propulsion System Simulation (C-MAPSS), which is representative of a 90,000-lb thrust class two spool, high bypass ratio commercial turbofan engine. A control law resembling the state-of-the-art on board modern aircraft engines is included, consisting of a fan-speed control loop supplemented by relevant engine limit protection regulator loops. The objective of this paper is to provide a top-down overview of the complete engine simulation package.

  12. Three-dimensional simulation of a novel rotary-piston engine in the motoring mode

    Directory of Open Access Journals (Sweden)

    Mohammadreza Khani

    2017-09-01

    Full Text Available In this simulation study, the flow and thermal characteristics of a novel rotary-piston engine, which is a kind of internal combustion engines, were investigated by computational fluid dynamics and the finite volume method. The structure of this engine is different to others, mainly for having 24 cylinders during the motoring mode. As a novel engine, creation of numerical models based on Reynolds average Navier Stokes (RANS simulation and analysis of various speed engines on the flow and thermal fields during intake and compression strokes are the focus of this work. The results were illustrated in term of the streamline patterns, in-cylinder temperature and pressure profile, swirl ratio (SR, wall heat flux, and turbulent velocity fluctuation. The present study indicates that, the mean pressure, temperature trace, and heat loss from the wall increase when switching to a higher engine speed. The temperature distribution reveals that the maximum temperature is restricted in the center of the combustion chamber near top dead center (TDC. Also, the maximum amount of turbulent velocity and swirl ratio are achieved at the beginning of the intake stroke and near TDC. It is observed that the obtained numerical results are in general agreement with the available experimental data.

  13. Higher efficiency by direct driven spindles with sensorless controlled engine speed in multi-axial machine tools for the timber industry; Verbesserte Energieeffizienz durch direktangetriebene winkelgeberlose drehzahlgeregelte Spindeln bei Mehrachsbohrkoepfen fuer die holzverarbeitende Industrie

    Energy Technology Data Exchange (ETDEWEB)

    Teisch, Arthur; Obernolte, Urs; Borcherding, Holger [Hochschule Ostwestfalen Lippe, Lemgo (Germany)

    2009-07-01

    The multi-axial machine tools work mainly with spindles, who are powered by a central motor with a gearbox. These drives have a relative little power efficiency. Due to the progress of the magnetic material it was possible to change the central motor with gear box by small direct driven spindles. Cause of the very high efficiency of the permanentmagnet synchronous machine (PMSM), it is the best option for the new application. With the option of the sensorless control of the rotor speed the costs for an encoder are saved too. With the good efficiency of the PMSM the overall degree of efficiency could be raised by about 70%. Because of the reduced investment, service and energy costs the new systems are more economical to operate. (orig.)

  14. Surface grinding characteristics of ferrous metals under high-speed and speed-stroke grinding conditions

    International Nuclear Information System (INIS)

    Ghani, A.K.; Choudhury, I.A.; Ahim, M.B.

    1999-01-01

    Some ferrous metals have been ground under different conditions with high-speed and speed-stroke in surface grinding operation. The paper describes experimental investigation of grinding forces in grinding some ferrous metals with the application of cutting fluids. Grinding tests have been carried out on mild steel, assab steel and stainless steel with different combinations of down feed and cross feed. The wheel speed was 27 m/sec while the table speed was maintained at the maximum possible 25 m/min. The grindability has been evaluated by measuring the grinding forces, grinding ratio, and surface finish. Grinding forces have been plotted against down feed of the grinding wheel and cross feed of the table. It has been observed that the radial and tangential grinding forces in stainless steel were higher than those in assab steel and mild steel

  15. Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture.

    Science.gov (United States)

    Karthikeya Sharma, T

    2015-11-01

    Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine's performance within the range studied.

  16. Improving speed behaviour : the potential of in-car speed assistance and speed limit credibility.

    NARCIS (Netherlands)

    Nes, C.N. van Houtenbos, M. & Schagen, I.N.L.G. van

    2009-01-01

    Speeding is still a common practice on many roads and it contributes to a significant number of crashes. Two new approaches to solve speeding issues are focused on: intelligent speed assistance systems (ISA) and speed limit credibility. Research has indicated that ISA is promising with respect to

  17. Recent progress in fan and compressor for aeroengine. Koku engine yo fan asshukuki no saikin no gijutsu shinpo

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y [National Aerospace Lab., Chofu, Tokyo (Japan)

    1994-03-10

    As the main components of the aeroengine, the fan and compressor reach to extremely high level stage technologically. Also at present when about 50 years passed after the jet engine was applied in practice, however, an effort for a modification is being continued, and furthermore even in the 1990s, the engines that adopted the new technologies are in succession being put in practical application. New engines in the 1990s are being applied in practice by adopting the study results on fan and compressor from the 1970s to the 1980s. Because, which way the future fan and compressor of the aircraft will go to has a relation with an aircraft trend from now on, and even in the 2000s the high subsonic speed aircrafts will be a center of the private air planes. The engine of high subsonic speed aircraft in the next generation will become an ultrahigh bypass ratio engine, the thrust efficiency is raised and noise is lowered, by lowering a fan pressure ratio and by increasing an air flow quantity compared with the current high bypass ratio turbofan engine. 16 figs.

  18. Temperature and air-fuel ratio dependent specific heat ratio functions for lean burned and unburned mixture

    International Nuclear Information System (INIS)

    Ceviz, M.A.; Kaymaz, I.

    2005-01-01

    The most important thermodynamic property used in heat release calculations for engines is the specific heat ratio. The functions proposed in the literature for the specific heat ratio are temperature dependent and apply at or near stoichiometric air-fuel ratios. However, the specific heat ratio is also influenced by the gas composition in the engine cylinder and especially becomes important for lean combustion engines. In this study, temperature and air-fuel ratio dependent specific heat ratio functions were derived to minimize the error by using an equilibrium combustion model for burned and unburned mixtures separately. After the error analysis between the equilibrium combustion model and the derived functions is presented, the results of the global specific heat ratio function, as varying with mass fraction burned, were compared with the proposed functions in the literature. The results of the study showed that the derived functions are more feasible at lean operating conditions of a spark ignition engine

  19. High speed network sampling

    OpenAIRE

    Rindalsholt, Ole Arild

    2005-01-01

    Master i nettverks- og systemadministrasjon Classical Sampling methods play an important role in the current practice of Internet measurement. With today’s high speed networks, routers cannot manage to generate complete Netflow data for every packet. They have to perform restricted sampling. This thesis summarizes some of the most important sampling schemes and their applications before diving into an analysis on the effect of sampling Netflow records.

  20. Nonlinear Thermodynamic Analysis and Optimization of a Carnot Engine Cycle

    Directory of Open Access Journals (Sweden)

    Michel Feidt

    2016-06-01

    Full Text Available As part of the efforts to unify the various branches of Irreversible Thermodynamics, the proposed work reconsiders the approach of the Carnot engine taking into account the finite physical dimensions (heat transfer conductances and the finite speed of the piston. The models introduce the irreversibility of the engine by two methods involving different constraints. The first method introduces the irreversibility by a so-called irreversibility ratio in the entropy balance applied to the cycle, while in the second method it is emphasized by the entropy generation rate. Various forms of heat transfer laws are analyzed, but most of the results are given for the case of the linear law. Also, individual cases are studied and reported in order to provide a simple analytical form of the results. The engine model developed allowed a formal optimization using the calculus of variations.

  1. Introducing a system of wind speed distributions for modeling properties of wind speed regimes around the world

    International Nuclear Information System (INIS)

    Jung, Christopher; Schindler, Dirk; Laible, Jessica; Buchholz, Alexander

    2017-01-01

    Highlights: • Evaluation of statistical properties of 10,016 empirical wind speed distributions. • Analysis of the shape of empirical wind speed distributions by L-moment ratios. • Introduction of a new system of wind speed distributions (Swd). • Random forests classification of the most appropriate distribution. • Comprehensive goodness of Swd fit evaluation on a global scale. - Abstract: Accurate modeling of empirical wind speed distributions is a crucial step in the estimation of average wind turbine power output. For this purpose, the Weibull distribution has often been fitted to empirical wind speed distributions. However, the Weibull distribution has been found to be insufficient to reproduce many wind speed regimes existing around the world. Results from previous studies demonstrate that numerous one-component distributions as well as mixture distributions provide a better goodness-of-fit to empirical wind speed distributions than the Weibull distribution. Moreover, there is considerable interest to apply a single system of distributions that can be utilized to reproduce the large majority of near-surface wind speed regimes existing around the world. Therefore, a system of wind speed distributions was developed that is capable of reproducing the main characteristics of existing wind speed regimes. The proposed system consists of two one-component distributions (Kappa and Wakeby) and one mixture distribution (Burr-Generalized Extreme Value). A random forests classifier was trained in order to select the most appropriate of these three distributions for each of 10,016 globally distributed empirical wind speed distributions. The shape of the empirical wind speed distributions was described by L-moment ratios. The L-moment ratios were used as predictor variables for the random forests classifier. The goodness-of-fit of the system of wind speed distributions was evaluated according to eleven goodness-of-fit metrics, which were merged into one

  2. High-Compression-Ratio; Atkinson-Cycle Engine Using Low-Pressure Direct Injection and Pneumatic-Electronic Valve Actuation Enabled by Ionization Current and Foward-Backward Mass Air Flow Sensor Feedback

    Energy Technology Data Exchange (ETDEWEB)

    Harold Schock; Farhad Jaberi; Ahmed Naguib; Guoming Zhu; David Hung

    2007-12-31

    This report describes the work completed over a two and one half year effort sponsored by the US Department of Energy. The goal was to demonstrate the technology needed to produce a highly efficient engine enabled by several technologies which were to be developed in the course of the work. The technologies included: (1) A low-pressure direct injection system; (2) A mass air flow sensor which would measure the net airflow into the engine on a per cycle basis; (3) A feedback control system enabled by measuring ionization current signals from the spark plug gap; and (4) An infinitely variable cam actuation system based on a pneumatic-hydraulic valve actuation These developments were supplemented by the use of advanced large eddy simulations as well as evaluations of fuel air mixing using the KIVA and WAVE models. The simulations were accompanied by experimental verification when possible. In this effort a solid base has been established for continued development of the advanced engine concepts originally proposed. Due to problems with the valve actuation system a complete demonstration of the engine concept originally proposed was not possible. Some of the highlights that were accomplished during this effort are: (1) A forward-backward mass air flow sensor has been developed and a patent application for the device has been submitted. We are optimistic that this technology will have a particular application in variable valve timing direct injection systems for IC engines. (2) The biggest effort on this project has involved the development of the pneumatic-hydraulic valve actuation system. This system was originally purchased from Cargine, a Swedish supplier and is in the development stage. To date we have not been able to use the actuators to control the exhaust valves, although the actuators have been successfully employed to control the intake valves. The reason for this is the additional complication associated with variable back pressure on the exhaust valves when

  3. Development of new 6-speed manual transmission for SKYLINE GT-R; Skyline GT-R yo shingata 6 soku manual transmission no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Hayami, H.; Kawasaki, M.; Yamamoto, K.; Gaber, J. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1999-06-01

    Described herein is a new 6-speed manual transmission (6MT), jointly developed for the new SKYLINE GT-R model. It adopts a close gear ratio, to realize light acceleration performance by improving drop of engine revolution number during the shift-up period by up to 12%. It has an increased synchro capacity by adopting a triple-cone synchro system for the first and second speeds, and double-cone synchro system for the third and fourth speeds, thereby decreasing shift operational force requirement by up to 35% from that for the conventional 5MT type. A non-symmetrical chamfer synchro structure is used for the second and third speeds, to reduce load generated when the speed is changed. The shift stroke is shortened by 24% by reviewing the dimensions. A high-rigidity shift lever and select stopper structure are adopted, to improve shift rigidity sensation. The transmission case is optimized, to reduce its weight while securing its rigidity. Transmission oil temperature is decreased by installing a cooling fan and increasing overdrive gear ratio. (NEDO)

  4. Balancing High-Speed Rotors at Low Speed

    Science.gov (United States)

    Giordano, J.; Zorzi, E.

    1986-01-01

    Flexible balancing reduces vibrations at operating speeds. Highspeed rotors in turbomachines dynamically balanced at fraction of operating rotor speed. New method takes into account rotor flexible rather than rigid.

  5. Cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with EGR

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Bin; Hu, Erjiang; Huang, Zuohua; Zheng, Jianjun; Liu, Bing; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, 710049 Xi' an (China)

    2009-10-15

    Study of cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation (EGR) was conducted. The effects of EGR ratio and hydrogen fraction on engine cycle-by-cycle variations are analyzed. The results show that the cylinder peak pressure, the maximum rate of pressure rise and the indicated mean effective pressure decrease and cycle-by-cycle variations increase with the increase of EGR ratio. Interdependency between the above parameters and their corresponding crank angles of cylinder peak pressure is decreased with the increase of EGR ratio. For a given EGR ratio, combustion stability is promoted and cycle-by-cycle variations are decreased with the increase of hydrogen fraction in the fuel blends. Non-linear relationship is presented between the indicated mean effective pressure and EGR ratio. Slight influence of EGR ratio on indicated mean effective pressure is observed at low EGR ratios while large influence of EGR ratio on indicated mean effective pressure is demonstrated at high EGR ratios. The high test engine speed has lower cycle-by-cycle variations due to the enhancement of air flow turbulence and swirls in the cylinder. Increasing hydrogen fraction can maintain low cycle-by-cycle variations at high EGR ratios. (author)

  6. Engineering Encounters: Engineering Adaptations

    Science.gov (United States)

    Gatling, Anne; Vaughn, Meredith Houle

    2015-01-01

    Engineering is not a subject that has historically been taught in elementary schools, but with the emphasis on engineering in the "Next Generation Science Standards," curricula are being developed to explicitly teach engineering content and design. However, many of the scientific investigations already conducted with students have…

  7. A new and efficient mechanism for spark ignition engines

    International Nuclear Information System (INIS)

    Shadloo, M.S.; Poultangari, R.; Abdollahzadeh Jamalabadi, M.Y.; Rashidi, M.M.

    2015-01-01

    Highlights: • A new slider–crank mechanism, with superior performance is presented. • Thermodynamic processes as well as vibration and internal forces have been modeled. • Comparison with the conventional four-stroke spark ignition engines is made. • Advantages and disadvantages of the proposed mechanism are discussed. - Abstract: In this paper a new symmetrical crank and slider mechanism is proposed and a zero dimensional model is utilized to study its combustion performance enhancement in a four-stroke spark ignition (SI) engine. The main features of this new mechanism are superior thermodynamic efficiency, lower internal frictions, and lower pollutants. Comparison is made between its performance and that of the conventional four-stroke SI engines. Presented mechanism is designed to provide better fuel consumption of internal combustion engines. These advantages over standard engine are achieved through synthesis of new mechanism. Numerical calculation have been performed for several cases of different mechanism parameters, compression ratio and engine speed. A comprehensive comparison between their thermodynamic processes as well as vibration and internal forces has been done. Calculated efficiency and power diagrams are plotted and compared with performance of a conventional SI engine. Advantages and disadvantages of the proposed mechanism are discussed in details

  8. Speed, speed variation and crash relationships for urban arterials.

    Science.gov (United States)

    Wang, Xuesong; Zhou, Qingya; Quddus, Mohammed; Fan, Tianxiang; Fang, Shou'en

    2018-04-01

    Speed and speed variation are closely associated with traffic safety. There is, however, a dearth of research on this subject for the case of urban arterials in general, and in the context of developing nations. In downtown Shanghai, the traffic conditions in each direction are very different by time of day, and speed characteristics during peak hours are also greatly different from those during off-peak hours. Considering that traffic demand changes with time and in different directions, arterials in this study were divided into one-way segments by the direction of flow, and time of day was differentiated and controlled for. In terms of data collection, traditional fixed-based methods have been widely used in previous studies, but they fail to capture the spatio-temporal distributions of speed along a road. A new approach is introduced to estimate speed variation by integrating spatio-temporal speed fluctuation of a single vehicle with speed differences between vehicles using taxi-based high frequency GPS data. With this approach, this paper aims to comprehensively establish a relationship between mean speed, speed variation and traffic crashes for the purpose of formulating effective speed management measures, specifically using an urban dataset. From a total of 234 one-way road segments from eight arterials in Shanghai, mean speed, speed variation, geometric design features, traffic volume, and crash data were collected. Because the safety effects of mean speed and speed variation may vary at different segment lengths, arterials with similar signal spacing density were grouped together. To account for potential correlations among these segments, a hierarchical Poisson log-normal model with random effects was developed. Results show that a 1% increase in mean speed on urban arterials was associated with a 0.7% increase in total crashes, and larger speed variation was also associated with increased crash frequency. Copyright © 2018 Elsevier Ltd. All rights

  9. Study of alcohol fuel of butanol and ethanol effect on the compression ignition (CI) engine performance, combustion and emission characteristic

    Science.gov (United States)

    Aziz, M. A.; Yusop, A. F.; Mat Yasin, M. H.; Hamidi, M. A.; Alias, A.; Hussin, H.; Hamri, S.

    2017-10-01

    Diesel engine which is one of the larger contributors to total consumption for petroleum is an attractive power unit used widely in many fields. However, diesel engines are among the main contributors to air pollutions for the large amount of emissions, such as CO, CO2 and NOx lead to an adverse effect on human health. Many researches have been done to find alternative fuels that are clean and efficient. Biodiesel is preferred as an alternative source for diesel engine which produces lower emission of pollutants. This study has focused on the evaluation of diesel and alcohol-diesel fuel properties and also the performance, combustion and exhaust emission from diesel engine fuelled with diesel and alcohol. Butanol and ethanol is blend with diesel fuel at 1:9 ratio. There are three test fuel that is tested which Diesel (100% diesel), D90BU10 (10% Butanol and 90% diesel) and D90E10 (10% Ethanol and 90% diesel). The comparison between diesel and alcohol-diesel blend has been made in terms of fuel properties characterization, engine performance such as brake power (BP) and brake specific fuel consumption (BSFC) also the in cylinder maximum pressure characteristic. Thus, exhaust gas emission of CO, CO2, NOx and O2 emission also has been observed at constant load of 50% but in different operating engine speed (1100 rpm, 1400 rpm, 1700 rpm, 2000 rpm and 2300 rpm). The results show the addition of 10% of each butanol and ethanol to diesel fuel had decreased the fuel density about 0.3% to 0.5% compared to mineral diesel. In addition, viscosity and energy content are also decrease. The addition of 10% butanol had improved the fuel cetane number however the ethanol blends react differently. In term of engine performance, as the engine speed increased, BP output also increase respectively. Hence, the alcohol blends fuel generates lower BP compared to diesel, plus BSFC for all test fuel shows decreasing trend at low and medium speed, however increased gradually at higher engine

  10. The role of visual processing speed in reading speed development.

    Science.gov (United States)

    Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

    2013-01-01

    A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

  11. Monitoring speed before and during a speed publicity campaign.

    NARCIS (Netherlands)

    Schagen, I.N.L.G. van Commandeur, J.J.F. Goldenbeld, C. & Stipdonk, H.

    2016-01-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small

  12. The role of visual processing speed in reading speed development.

    Directory of Open Access Journals (Sweden)

    Muriel Lobier

    Full Text Available A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span, predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

  13. VVER-1000 dominance ratio

    International Nuclear Information System (INIS)

    Gorodkov, S.

    2009-01-01

    Dominance ratio, or more precisely, its closeness to unity, is important characteristic of large reactor. It allows evaluate beforehand the number of source iterations required in deterministic calculations of power spatial distribution. Or the minimal number of histories to be modeled for achievement of statistical error level desired in large core Monte Carlo calculations. In this work relatively simple approach for dominance ratio evaluation is proposed. It essentially uses core symmetry. Dependence of dominance ratio on neutron flux spatial distribution is demonstrated. (author)

  14. WWER-1000 dominance ratio

    International Nuclear Information System (INIS)

    Gorodkov, S.S.

    2009-01-01

    Dominance ratio, or more precisely, its closeness to unity, is important characteristic of large reactor. It allows evaluate beforehand the number of source iterations required in deterministic calculations of power spatial distribution. Or the minimal number of histories to be modeled for achievement of statistical error level desired in large core Monte Carlo calculations. In this work relatively simple approach for dominance ratio evaluation is proposed. It essentially uses core symmetry. Dependence of dominance ratio on neutron flux spatial distribution is demonstrated. (Authors)

  15. Engine performance and emission of compression ignition engine fuelled with emulsified biodiesel-water

    Science.gov (United States)

    Maawa, W. N.; Mamat, R.; Najafi, G.; Majeed Ali, O.; Aziz, A.

    2015-12-01

    The depletion of fossil fuel and environmental pollution has become world crucial issues in current era. Biodiesel-water emulsion is one of many possible approaches to reduce emissions. In this study, emulsified biodiesel with 4%, 6% and 8% of water contents were prepared to be used as fuel in a direct injection compression ignition engine. The performance indicator such as brake power, brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) and emissions such as NOx and particulate matter (PM) were investigated. The engine was set at constant speed of 2500 rpm and load from 20% to 60%. All the results were compared to B5 (blend of 95% petroleum diesel and 5% palm oil biodiesel) biodiesel. At low load, the BSFC decrease by 12.75% at 4% water ratio and decreased by 1.5% at 6% water ratio. However, the BSFC increases by 17.19% with increasing water ratio to 8% compared to B5. Furthermore, there was no significant decrease in brake power and BTE at 60% load. For 20% and 40% load there was some variance regarding to brake power and BTE. Significant reduction in NOx and PM emissions by 73.87% and 20.00% respectively were achieved with increasing water ratio to 8%. Overall, it is observed that the emulsified of biodiesel-water is an appropriate alternative fuel method to reduce emissions.

  16. Sharpening Sharpe Ratios

    OpenAIRE

    William N. Goetzmann; Jonathan E. Ingersoll Jr.; Matthew I. Spiegel; Ivo Welch

    2002-01-01

    It is now well known that the Sharpe ratio and other related reward-to-risk measures may be manipulated with option-like strategies. In this paper we derive the general conditions for achieving the maximum expected Sharpe ratio. We derive static rules for achieving the maximum Sharpe ratio with two or more options, as well as a continuum of derivative contracts. The optimal strategy has a truncated right tail and a fat left tail. We also derive dynamic rules for increasing the Sharpe ratio. O...

  17. 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)

  18. Acoustic measurements for the combustion diagnosis of diesel engines fuelled with biodiesels

    Science.gov (United States)

    Zhen, Dong; Wang, Tie; Gu, Fengshou; Tesfa, Belachew; Ball, Andrew

    2013-05-01

    In this paper, an experimental investigation was carried out on the combustion process of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The effects of biodiesel on the combustion process and engine dynamics were analysed for non-intrusive combustion diagnosis based on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine. The signals of vibration, acoustic and in-cylinder pressure were measured simultaneously to find their inter-connection for diagnostic feature extraction. It was found that the sound energy level increases with the increase of engine load and speed, and the sound characteristics are closely correlated with the variation of in-cylinder pressure and combustion process. The continuous wavelet transform (CWT) was employed to analyse the non-stationary nature of engine noise in a higher frequency range. Before the wavelet analysis, time synchronous average (TSA) was used to enhance the signal-to-noise ratio (SNR) of the acoustic signal by suppressing the components which are asynchronous. Based on the root mean square (RMS) values of CWT coefficients, the effects of biodiesel fractions and operating conditions (speed and load) on combustion process and engine dynamics were investigated. The result leads to the potential of airborne acoustic measurements and analysis for engine condition monitoring and fuel quality evaluation.

  19. Acoustic measurements for the combustion diagnosis of diesel engines fuelled with biodiesels

    International Nuclear Information System (INIS)

    Zhen, Dong; Gu, Fengshou; Tesfa, Belachew; Ball, Andrew; Wang, Tie

    2013-01-01

    In this paper, an experimental investigation was carried out on the combustion process of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The effects of biodiesel on the combustion process and engine dynamics were analysed for non-intrusive combustion diagnosis based on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine. The signals of vibration, acoustic and in-cylinder pressure were measured simultaneously to find their inter-connection for diagnostic feature extraction. It was found that the sound energy level increases with the increase of engine load and speed, and the sound characteristics are closely correlated with the variation of in-cylinder pressure and combustion process. The continuous wavelet transform (CWT) was employed to analyse the non-stationary nature of engine noise in a higher frequency range. Before the wavelet analysis, time synchronous average (TSA) was used to enhance the signal-to-noise ratio (SNR) of the acoustic signal by suppressing the components which are asynchronous. Based on the root mean square (RMS) values of CWT coefficients, the effects of biodiesel fractions and operating conditions (speed and load) on combustion process and engine dynamics were investigated. The result leads to the potential of airborne acoustic measurements and analysis for engine condition monitoring and fuel quality evaluation. (paper)

  20. Fast visual prediction and slow optimization of preferred walking speed.

    Science.gov (United States)

    O'Connor, Shawn M; Donelan, J Maxwell

    2012-05-01

    People prefer walking speeds that minimize energetic cost. This may be accomplished by directly sensing metabolic rate and adapting gait to minimize it, but only slowly due to the compounded effects of sensing delays and iterative convergence. Visual and other sensory information is available more rapidly and could help predict which gait changes reduce energetic cost, but only approximately because it relies on prior experience and an indirect means to achieve economy. We used virtual reality to manipulate visually presented speed while 10 healthy subjects freely walked on a self-paced treadmill to test whether the nervous system beneficially combines these two mechanisms. Rather than manipulating the speed of visual flow directly, we coupled it to the walking speed selected by the subject and then manipulated the ratio between these two speeds. We then quantified the dynamics of walking speed adjustments in response to perturbations of the visual speed. For step changes in visual speed, subjects responded with rapid speed adjustments (lasting 300 s). The timing and direction of these responses strongly indicate that a rapid predictive process informed by visual feedback helps select preferred speed, perhaps to complement a slower optimization process that seeks to minimize energetic cost.

  1. An experimental study for the effects of boost pressure on the performance and exhaust emissions of a DI-HCCI gasoline engine

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa Canakci [Kocaeli University, Izmit (Turkey). Department of Mechanical Education

    2008-07-15

    As an alternative combustion mode, the HCCI combustion has some benefits compared to conventional SI and CI engines, such as low NOx emission and high thermal efficiency. However, this combustion mode can produce higher UHC and CO emissions than those of conventional engines. In the naturally aspirated HCCI engines, the low engine output power limits its use in the current engine technologies. Intake air pressure boosting is a common way to improve the engine output power which is widely used in high performance SI and CI engine applications. Therefore, in this study, the effect of inlet air pressure on the performance and exhaust emissions of a DI-HCCI gasoline engine has been investigated after converting a heavy-duty diesel engine to a HCCI direct-injection gasoline engine. The experiments were performed at three different inlet air pressures while operating the engine at the same equivalence ratio and intake air temperature as in normally aspirated HCCI engine condition at different engine speeds. The SOI timing was set dependently to achieve the maximum engine torque at each test condition. The effects of inlet air pressure both on the emissions such as CO, UHC and NOx and on the performance parameters such as BSFC, torque, thermal and combustion efficiencies have been discussed. The relationships between the emissions are also provided. 34 refs., 19 figs., 4 tabs.

  2. 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.

  3. Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

    Science.gov (United States)

    Ketchum, James R.; Blivas, Darnold; Pack, George J.

    1950-01-01

    The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

  4. Gravitational Wave Speed: Undefined. Experiments Proposed

    Directory of Open Access Journals (Sweden)

    Daniel Russell

    2018-04-01

    Full Text Available Since changes in all 4 dimensions of spacetime are components of displacement for gravitational waves, a theoretical result is presented that their speed is undefined, and that the Theory of Relativity is not reliable to predict their speed. Astrophysical experiments are proposed with objectives to directly measure gravitational wave speed, and to verify these theoretical results. From the circumference of two merging black hole's final orbit, it is proposed to make an estimate of a total duration of the last ten orbits, before gravitational collapse, for comparison with durations of reported gravitational wave signals. It is proposed to open a new field of engineering of spacetime wave modulation with an objective of faster and better data transmission and communication through the Earth, the Sun, and deep space. If experiments verify that gravitational waves have infinite speed, it is concluded that a catastrophic gravitational collapse, such as a merger of quasars, today, would re-define the geometry and curvature of spacetime on Earth, instantly, without optical observations of this merger visible, until billions of years in the future.

  5. Speeding Fermat's factoring method

    Science.gov (United States)

    McKee, James

    A factoring method is presented which, heuristically, splits composite n in O(n^{1/4+epsilon}) steps. There are two ideas: an integer approximation to sqrt(q/p) provides an O(n^{1/2+epsilon}) algorithm in which n is represented as the difference of two rational squares; observing that if a prime m divides a square, then m^2 divides that square, a heuristic speed-up to O(n^{1/4+epsilon}) steps is achieved. The method is well-suited for use with small computers: the storage required is negligible, and one never needs to work with numbers larger than n itself.

  6. High Speed Photomicrography

    Science.gov (United States)

    Hyzer, William G.

    1983-03-01

    One of the most challenging areas in applying high-speed photography and videography in the plant and laboratory is in the recording of rapid events at macro and microscopic scales. Depth of field, exposure efficiency, working distance, and required exposure time are all reduced as optical magnification is increased, which severely taxes the skill and ingenuity of workers interested in recording any fast moving phenomena through the microscope or with magnifying lenses. This paper defines the problems inherent in photographing within macro and microscopic ranges and offers a systematic approach to optimizing the selection of equipment and choice of applicable techniques.

  7. Speeding Up Innovation

    DEFF Research Database (Denmark)

    Sørensen, Flemming; Mattsson, Jan

    2016-01-01

    Minimisation of time-to-market strategies can provide companies with a competitive advantage in dynamic and competitive environments. Using parallel innovation processes has been emphasised as one strategy to speed up innovation processes and consequently minimise the time-to-market of innovations....... Much innovation today takes place in open structures in which networks play an important role. However, little is known about how innovation networks can facilitate parallel innovation processes. This paper discusses how innovation network structures develop and support exploration and exploitation...... of the network facilitate the parallel innovation process but also how such processes place new requirements on such networks and their management....

  8. High speed rotary drum

    Energy Technology Data Exchange (ETDEWEB)

    Sagara, H

    1970-03-25

    A high speed rotary drum is disclosed in which the rotor vessel is a double-wall structure comprising an inner wave-shaped pipe inserted coaxially within an outer straight pipe, the object being to provide a strengthened composite light-weight structure. Since force induced axial deformation of the straight pipe and radial deformation of the corrugated pipe are small, the composite effectively resists external forces and, if the waves of the inner pipe are given a sufficient amplitude, the thickness of both pipes may be reduced to lower the overall weight. Thus high angular velocities can be obtained to separate U/sup 235/ from gaseous UF/sub 6/.

  9. 46 CFR 121.620 - Propulsion engine control systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

  10. DC motor speed control using fuzzy logic controller

    Science.gov (United States)

    Ismail, N. L.; Zakaria, K. A.; Nazar, N. S. Moh; Syaripuddin, M.; Mokhtar, A. S. N.; Thanakodi, S.

    2018-02-01

    The automatic control has played a vital role in the advance of engineering and science. Nowadays in industries, the control of direct current (DC) motor is a common practice thus the implementation of DC motor controller speed is important. The main purpose of motor speed control is to keep the rotation of the motor at the present speed and to drive a system at the demand speed. The main purpose of this project is to control speed of DC Series Wound Motor using Fuzzy Logic Controller (FLC). The expectation of this project is the Fuzzy Logic Controller will get the best performance compared to dc motor without controller in terms of settling time (Ts), rise time (Tr), peak time (Tp) and percent overshoot (%OS).

  11. Evaluation of high-speed films for measuring decelerations in experimental collisions. Paper presented to the Society of Photo-optical Instrumentation Engineer's Seminar in Depth and Equipment Demonstration: Optical Instrumentation, A problem solving tool in automotive safety engineering and biomechanics, Dearborn, Michigan, November 20-21, 1972.

    NARCIS (Netherlands)

    Botma, H.

    1990-01-01

    High-speed filming of collisions of vehicles with e.g. obstacles can be used to yield quantitative information. To get the deceleration history of the vehicle the series of positions read from the film should be different tinted twice. As the positions are corrupted with noise, the differentiating

  12. Simulation of a combined-cycle engine

    Science.gov (United States)

    Vangerpen, Jon

    1991-01-01

    A FORTRAN computer program was developed to simulate the performance of combined-cycle engines. These engines combine features of both gas turbines and reciprocating engines. The computer program can simulate both design point and off-design operation. Widely varying engine configurations can be evaluated for their power, performance, and efficiency as well as the influence of altitude and air speed. Although the program was developed to simulate aircraft engines, it can be used with equal success for stationary and automative applications.

  13. Speed control variable rate irrigation

    Science.gov (United States)

    Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

  14. Safe Speeds and Credible Speed Limits (SaCredSpeed): New Vision for Decision Making on Speed Management.

    NARCIS (Netherlands)

    Aarts, L. Nes, N. van Wegman, F.C.M. Schagen, I.N.L.G. van & Louwerse, R.

    2009-01-01

    Speed is an inherent characteristic of mobility and a hazard to safety. Several approaches exist of how to manage speed. In the Netherlands, the emphasis has mainly been on harm minimisation during the last decades, due to the implementation of the Sustainable Safety vision. Speed management remains

  15. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1985-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  16. Detecting isotopic ratio outliers

    Science.gov (United States)

    Bayne, C. K.; Smith, D. H.

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers.

  17. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1986-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers

  18. Studies on variable swirl intake system for DI diesel engine using computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    Jebamani Rathnaraj David

    2008-01-01

    Full Text Available It is known that a helical port is more effective than a tangential port to attain the required swirl ratio with minimum sacrifice in the volumetric efficiency. The swirl port is designed for lesser swirl ratio to reduce emissions at higher speeds. But this condition increases the air fuel mixing time and particulate smoke emissions at lower speeds. Optimum swirl ratio is necessary according to the engine operating condition for optimum combustion and emission reduction. Hence the engine needs variable swirl to enhance the combustion in the cylinder according to its operating conditions, for example at partial load or low speed condition it requires stronger swirl, while the air quantity is more important than the swirl under very high speed or full load and maximum torque conditions. The swirl and charging quantity can easily trade off and can be controlled by the opening of the valve. Hence in this study the steady flow rig experiment is used to evaluate the swirl of a helical intake port design for different operating conditions. The variable swirl plate set up of the W06DTIE2 engine is used to experimentally study the swirl variation for different openings of the valve. The sliding of the swirl plate results in the variation of the area of inlet port entry. Therefore in this study a swirl optimized combustion system varying according to the operating conditions by a variable swirl plate mechanism is studied experimentally and compared with the computational fluid dynamics predictions. In this study the fluent computational fluid dynamics code has been used to evaluate the flow in the port-cylinder system of a DI diesel engine in a steady flow rig. The computational grid is generated directly from 3-D CAD data and in cylinder flow simulations, with inflow boundary conditions from experimental measurements, are made using the fluent computational fluid dynamics code. The results are in very good agreement with experimental results.

  19. Pay as You Speed, ISA with incentives for not speeding

    DEFF Research Database (Denmark)

    Lahrmann, Harry Spaabæk; Agerholm, Niels; Tradisauskas, Nerius

    2012-01-01

    The Intelligent Speed Adaptation (ISA) project we describe in this article is based on Pay as You Drive principles. These principles assume that the ISA equipment informs a driver of the speed limit, warns the driver when speeding and calculates penalty points. Each penalty point entails the redu......The Intelligent Speed Adaptation (ISA) project we describe in this article is based on Pay as You Drive principles. These principles assume that the ISA equipment informs a driver of the speed limit, warns the driver when speeding and calculates penalty points. Each penalty point entails...... the reduction of a 30% discount on the driver's car insurance premium, which therefore produced the name, Pay as You Speed. The ISA equipment consists of a GPS-based On Board Unit with a mobile phone connection to a web server. The project was planned for a three-year test period with 300 young car drivers...

  20. Feedforward mapping for engine control

    OpenAIRE

    Aran, Volkan; Ünel, Mustafa; Unel, Mustafa

    2016-01-01

    Feedforward control is widely used in electronic control units of internal combustion engines besides feedback controls. However, almost all feedforward control values are used in table form, also called maps, having engine speed and engine torque in their axes. Table approach limits all inte ractions in two input dimensions. This paper focuses on application of Gaussian process modelling of errors of inverse parametric model of the valve position. Validation results based on ...

  1. Combustion phasing for maximum efficiency for conventional and high efficiency engines

    International Nuclear Information System (INIS)

    Caton, Jerald A.

    2014-01-01

    Highlights: • Combustion phasing for max efficiency is a function of engine parameters. • Combustion phasing is most affected by heat transfer, compression ratio, burn duration. • Combustion phasing is less affected by speed, load, equivalence ratio and EGR. • Combustion phasing for a high efficiency engine was more advanced. • Exergy destruction during combustion as functions of combustion phasing is reported. - Abstract: The importance of the phasing of the combustion event for internal-combustion engines is well appreciated, but quantitative details are sparse. The objective of the current work was to examine the optimum combustion phasing (based on maximum bmep) as functions of engine design and operating variables. A thermodynamic, engine cycle simulation was used to complete this assessment. As metrics for the combustion phasing, both the crank angle for 50% fuel mass burned (CA 50 ) and the crank angle for peak pressure (CA pp ) are reported as functions of the engine variables. In contrast to common statements in the literature, the optimum CA 50 and CA pp vary depending on the design and operating variables. Optimum, as used in this paper, refers to the combustion timing that provides the maximum bmep and brake thermal efficiency (MBT timing). For this work, the variables with the greatest influence on the optimum CA 50 and CA pp were the heat transfer level, the burn duration and the compression ratio. Other variables such as equivalence ratio, EGR level, engine speed and engine load had a much smaller impact on the optimum CA 50 and CA pp . For the conventional engine, for the conditions examined, the optimum CA 50 varied between about 5 and 11°aTDC, and the optimum CA pp varied between about 9 and 16°aTDC. For a high efficiency engine (high dilution, high compression ratio), the optimum CA 50 was 2.5°aTDC, and the optimum CA pp was 7.8°aTDC. These more advanced values for the optimum CA 50 and CA pp for the high efficiency engine were

  2. Motor Integrated Permanent Magnet Gear with a Wide Torque-Speed Range

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Matzen, Torben N.; Jahns, T. M.

    2009-01-01

    This paper present a new motor integrated permanent magnet gear with a wide torque-speed range. In the paper a 35 kW permanent magnet motor with a base speed of 4000 rpm and a top speed of 14000 rpm is integrated into a permanent magnetic gear with a gearing ratio of 8.67. The design process...

  3. Evaluation of cutting force and surface roughness in high-speed milling of compacted graphite iron

    Directory of Open Access Journals (Sweden)

    Azlan Suhaimi Mohd

    2017-01-01

    Full Text Available Compacted Graphite Iron, (CGI is known to have outstanding mechanical strength and weight-to-strength ratio as compared to conventional grey cast iron, (CI. The outstanding characteristics of CGI is due to its graphite particle shape, which is presented as compacted vermicular particle. The graphite is interconnected with random orientation and round edges, which results in higher mechanical strength. Whereas, graphite in the CI consists of a smooth-surfaced flakes that easily propagates cracks which results in weaker and brittle properties as compared to CGI. Owing to its improved properties, CGI is considered as the best candidate material in substituting grey cast iron that has been used in engine block applications for years. However, the smooth implementation of replacing CI with CGI has been hindered due to the poor machinability of CGI especially at high cutting speed. The tool life is decreased by 20 times when comparing CGI with CI under the same cutting condition. This study investigates the effect of using cryogenic cooling and minimum quantity lubrication (MQL during high-speed milling of CGI (grade 450. Results showed that, the combination of internal cryogenic cooling and enhanced MQL improved the tool life, cutting force and surface quality as compared to the conventional flood coolant strategy during high-speed milling of CGI.

  4. Composition and comparative toxicity of particulate matter emitted from a diesel and biodiesel fuelled CRDI engine

    Science.gov (United States)

    Gangwar, Jitendra N.; Gupta, Tarun; Agarwal, Avinash K.

    2012-01-01

    There is a global concern about adverse health effects of particulate matter (PM) originating from diesel engine exhaust. In the current study, parametric investigations were carried out using a CRDI (Common Rail Direct Injection) diesel engine operated at different loads at two different engine speeds (1800 and 2400 rpm), employing diesel and 20% biodiesel blends (B20) produced from Karanja oil. A partial flow dilution tunnel was employed to collect and measure the mass of the primary particulates from diesel and biodiesel blend collected on a 47 mm quartz substrate. The collected PM (particulate matter) was subjected to chemical analyses in order to assess the amount of Benzene Soluble Organic Fraction (BSOF) and trace metals using Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). For both diesel and biodiesel, BSOF results showed decreasing levels with increasing engine load. B20 showed higher BSOF as compared to those measured with diesel. The concentration of different trace metals analyzed also showed decreasing trends with increasing engine loads. In addition, real-time measurements for Organic Carbon (OC), Elemental Carbon (EC) and total particle-bound Polycyclic Aromatic Hydrocarbons (PAHs) were carried out on the primary engine exhaust coming out of the partial flow dilution tunnel. Analysis of OC/EC data suggested that the ratio of OC to EC decreases with corresponding increase in engine load for both fuels. A peak in PAH concentration was observed at 60% engine load at 1800 rpm and 20% engine load at 2400 rpm engine speeds almost identical for both kinds of fuels. Comparison of chemical components of PM emitted from this CRDI engine provides new insight in terms of PM toxicity for B20 vis-a-vis diesel.

  5. Model Engine Performance Measurement From Force Balance Instrumentation

    Science.gov (United States)

    Jeracki, Robert J.

    1998-01-01

    A large scale model representative of a low-noise, high bypass ratio turbofan engine was tested for acoustics and performance in the NASA Lewis 9- by 15-Foot Low-Speed Wind Tunnel. This test was part of NASA's continuing Advanced Subsonic Technology Noise Reduction Program. The low tip speed fan, nacelle, and an un-powered core passage (with core inlet guide vanes) were simulated. The fan blades and hub are mounted on a rotating thrust and torque balance. The nacelle, bypass duct stators, and core passage are attached to a six component force balance. The two balance forces, when corrected for internal pressure tares, measure the total thrust-minus-drag of the engine simulator. Corrected for scaling and other effects, it is basically the same force that the engine supports would feel, operating at similar conditions. A control volume is shown and discussed, identifying the various force components of the engine simulator thrust and definitions of net thrust. Several wind tunnel runs with nearly the same hardware installed are compared, to identify the repeatability of the measured thrust-minus-drag. Other wind tunnel runs, with hardware changes that affected fan performance, are compared to the baseline configuration, and the thrust and torque effects are shown. Finally, a thrust comparison between the force balance and nozzle gross thrust methods is shown, and both yield very similar results.

  6. 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.

  7. Study of two-stage turbine characteristic and its influence on turbo-compound engine performance

    International Nuclear Information System (INIS)

    Zhao, Rongchao; Zhuge, Weilin; Zhang, Yangjun; Yang, Mingyang; Martinez-Botas, Ricardo; Yin, Yong

    2015-01-01

    Highlights: • An analytical model was built to study the interactions between two turbines in series. • The impacts of HP VGT and LP VGT on turbo-compound engine performance were investigated. • The fuel reductions obtained by HP VGT at 1900 rpm and 1000 rpm are 3.08% and 7.83% respectively. • The optimum value of AR ranged from 2.0 to 2.5 as the turbo-compound engine speed decreases. - Abstract: Turbo-compounding is an effective way to recover waste heat from engine exhaust and reduce fuel consumption for internal combustion engine (ICE). The characteristics of two-stage turbine, including turbocharger turbine and power turbine, have significant effects on the overall performance of turbo-compound engine. This paper investigates the interaction between two turbines in a turbo-compound engine and its impact on the engine performance. Firstly an analytical model is built to investigate the effects of turbine equivalent flow area on the two-stage turbine characteristics, including swallowing capacity and load split. Next both simulation and experimental method are carried out to study the effects of high pressure variable geometry turbine (HP VGT), low pressure variable geometry turbine (LP VGT) and combined VGT on the engine overall performance. The results show that the engine performance is more sensitive to HP VGT compared with LP VGT at all the operation conditions, which is caused by the larger influences of HP VGT on the total expansion ratio and engine air–fuel ratio. Using the HP VGT method, the fuel reductions of the turbo-compound engine at 1900 rpm and 1000 rpm are 3.08% and 7.83% respectively, in comparison with the baseline engine. The corresponding optimum values of AR are 2.0 and 2.5

  8. Transient flow characteristics of a high speed rotary valve

    Science.gov (United States)

    Browning, Patrick H.

    were experimentally mapped as a function of valve speed, inter-cylinder pressure ratios and volume ratios and the results were compared to compressible flow theoretical models. Specifically, the transient behavior suggested a short-lived loss-mode initiation closely resembled by shock tube theory followed by a quasi-steady flow regime resembling choked flow behavior. An empirical model was then employed to determine the useful range of the CCV design as applied to a four-stroke CIBAI engine cycle modeled using a 1-D quasi-steady numerical method, with particular emphasis on the cyclic timing of the CCV opening. Finally, a brief discussion of a high-temperature version of the CCV design is presented.

  9. Performance of Diesel Engine Using Diesel B3 Mixed with Crude Palm Oil

    Science.gov (United States)

    Namliwan, Nattapong; Wongwuttanasatian, Tanakorn

    2014-01-01

    The objective of this study was to test the performance of diesel engine using diesel B3 mixed with crude palm oil in ratios of 95 : 5, 90 : 10, and 85 : 15, respectively, and to compare the results with diesel B3. According to the tests, they showed that the physical properties of the mixed fuel in the ratio of 95 : 5 were closest to those of diesel B3. The performance of the diesel engine that used mixed fuels had 5–17% lower torque and power than that of diesel B3. The specific fuel consumption of mixed fuels was 7–33% higher than using diesel B3. The components of gas emissions by using mixed fuel had 1.6–52% fewer amount of carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), and oxygen (O2) than those of diesel B3. On the other hand, nitric oxide (NO) and nitrogen oxides (NOX) emissions when using mixed fuels were 10–39% higher than diesel B3. By comparing the physical properties, the performance of the engine, and the amount of gas emissions of mixed fuel, we found out that the 95 : 5 ratio by volume was a suitable ratio for agricultural diesel engine (low-speed diesel engine). PMID:24688402

  10. Performance of diesel engine using diesel B3 mixed with crude palm oil.

    Science.gov (United States)

    Namliwan, Nattapong; Wongwuttanasatian, Tanakorn

    2014-01-01

    The objective of this study was to test the performance of diesel engine using diesel B3 mixed with crude palm oil in ratios of 95 : 5, 90 : 10, and 85 : 15, respectively, and to compare the results with diesel B3. According to the tests, they showed that the physical properties of the mixed fuel in the ratio of 95 : 5 were closest to those of diesel B3. The performance of the diesel engine that used mixed fuels had 5-17% lower torque and power than that of diesel B3. The specific fuel consumption of mixed fuels was 7-33% higher than using diesel B3. The components of gas emissions by using mixed fuel had 1.6-52% fewer amount of carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), and oxygen (O2) than those of diesel B3. On the other hand, nitric oxide (NO) and nitrogen oxides (NO X ) emissions when using mixed fuels were 10-39% higher than diesel B3. By comparing the physical properties, the performance of the engine, and the amount of gas emissions of mixed fuel, we found out that the 95 : 5 ratio by volume was a suitable ratio for agricultural diesel engine (low-speed diesel engine).

  11. Thermal balance of a four stroke SI engine operating on hydrogen as a supplementary fuel

    International Nuclear Information System (INIS)

    Yueksel, F.; Ceviz, M.A.

    2003-01-01

    This paper investigates the effects of adding constant quantity hydrogen to gasoline-air mixture on SI engine thermal balance and performance. A four stroke, four-cylinder SI engine was used for conducting this study. Thermal balance tests were conducted for engine thermal efficiency, heat loss through the exhaust gases, heat loss to the cooling water and unaccounted losses (i.e. heat lost by lubricating oil, radiation), while performance tests were in respect to the brake power, specific fuel consumption and air ratio. Hydrogen supplementations were used with three different and fixed mass flow rates; 0.129, 0.168 and 0.208 kg h -1 at near three-fourth throttle opening position and variable engine speed ranging from 1000 to 4500 rpm. The results showed that supplementation of hydrogen to gasoline decreases the heat loss to cooling water and unaccounted losses, and the heat loss through the exhaust gas is nearly the same with pure gasoline experiments. Additionally, specific fuel consumption decreases, while the engine thermal efficiency and the air ratio increase. Engine performance parameters such as thermal efficiency and specific fuel consumption improved the level of the ratio of hydrogen mass flow rate to that of gasoline up to 5%

  12. High-speed elevators controlled by inverters

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yoshio; Takahashi, Hideaki; Nakamura, Kiyoshi; Kinoshita, Hiroshi

    1988-10-25

    The super-high-speed elevator with superiority to 300m/min of speed, requires both the large capacity power and wide range speed controls. Therefore, in order to materialize the smooth and quiet operation characteristics, by applying the inverter control, the low torque ripple control in the low frequency range and high frequency large capacity inverting for lowering the motor in noise are necessary with their being assured of reliability. To satisfy the above necessary items, together with the development of a sine wave pulse width and frequency modulation (PWM/PFM) control system, to more precisely enable the sine wave electric current control, and 3kHz switching power converter, using a 800A power transistor module, a supervoltage control circuit under the extraordinary condition was designed. As a result of commercializing a 360m/min super-high speed inverter elevator, the power source unit, due to the effect of high power factor, could be reduced by 30% in capacity and also the higher harmonic wave including ratio could be considerably lowered to the inferiority to 5%. 2 references, 7 figures, 1 table.

  13. Experimental investigation of gasoline fumigation in a single cylinder direct injection (DI) diesel engine

    International Nuclear Information System (INIS)

    Sahin, Z.; Durgun, O.; Bayram, C.

    2008-01-01

    In the presented study, the effects of gasoline fumigation have been investigated experimentally in a single cylinder direct injection (DI) diesel engine. Gasoline has been introduced into the inlet air flow using an elementary carburetor and no other modification on the engine has been done. The effects of 2%, 4%, 6%, 8% and 10% (by vol.) gasoline fumigation have been investigated experimentally at the speeds of (900-1600) (rpm) and at the selected compression ratios of (18-23). From the experimental results it is determined that by application of gasoline fumigation effective power output increases at the levels of 4-9%, effective efficiency increases by approximately 1.5-4% and specific fuel consumption decreases by approximately 1.5-4%. It is also determined that 4-6% fumigation ratio range is the most favorable percentage interval of gasoline at the selected compression ratios for this engine. Because cost of gasoline is higher than diesel fuel in Turkey as well as in many of the other countries and the decrease ratio of specific fuel consumption is low, gasoline fumigation is not economic for this engine. In the presented study, heat balance tests have also been performed for 18 and 21 compression ratios. The heat balance has been investigated experimentally in respect of effective power, heat rejected to the cooling water, heat lost through exhaust, and other losses (unaccounted-for losses). Heat lost through exhaust decreases until 4-6% gasoline fumigation ratios and after these fumigation ratios it starts to increase because of increasing exhaust gas temperature. Heat rejected to the cooling water decreases at low fumigation ratios, but at high fumigation ratios it increases. Other losses generally exhibit an increasing tendency at low fumigation ratios

  14. Speeding up innovation in agricultural IT

    Directory of Open Access Journals (Sweden)

    Hannu E.S. Haapala

    2013-09-01

    Full Text Available An OECD funded research was conducted where methods and processes for speeding up innovation in agriculture were assessed. A global web-based questionnaire was sent to experts in agricultural engineering, research, marketing, education and users of new technologies. Interviews of selected experts were done to deepen the analysis. The results show that considerable part of the relatively slow innovation comes from the fact that users do not trust in new technologies or that the usability of them is unacceptable. The experts suggest that education of the engineers and designers should include more elements from User-Centered Design (UCD and also User-Driven Innovation methods should be more used. As a conclusion a new ‘Dream Team’ of agricultural innovation was developed where user interaction and marketing professionals were given more roles.

  15. Adjustable speed drives improve circulating water system

    International Nuclear Information System (INIS)

    Dent, R.A.; Dicic, Z.

    1994-01-01

    This paper illustrates the integration of electrical and mechanical engineering requirements to produce a solution to past problems and future operating demands. The application of adjustable speed drives in the modifications of the circulating water system at Indian Point No. 3 Nuclear Power Plant provided increased operating flexibility, efficiency and avoided otherwise costly renovations to the plant electrical systems. Rectification of the original inadequate design of the circulating water system, in addition to maximizing plant efficiency consistent with environmental considerations, formed the basis for this modification. This entailed replacement of all six circulating water pumps and motors and physical modifications to the intake system. This paper details the methodology used in this engineering task. The new system was installed successfully and has been operating reliably and economically for the past eight years

  16. Difference and ratio plots

    DEFF Research Database (Denmark)

    Svendsen, Anders Jørgen; Holmskov, U; Bro, Peter

    1995-01-01

    and systemic lupus erythematosus from another previously published study (Macanovic, M. and Lachmann, P.J. (1979) Clin. Exp. Immunol. 38, 274) are also represented using ratio plots. Our observations indicate that analysis by regression analysis may often be misleading....... hitherto unnoted differences between controls and patients with either rheumatoid arthritis or systemic lupus erythematosus. For this we use simple, but unconventional, graphic representations of the data, based on difference plots and ratio plots. Differences between patients with Burkitt's lymphoma...

  17. Method for reduction of the NOX emissions in marine auxiliary diesel engine using the fuel mixtures containing biodiesel using HCCI combustion.

    Science.gov (United States)

    Puškár, Michal; Kopas, Melichar; Puškár, Dušan; Lumnitzer, Ján; Faltinová, Eva

    2018-02-01

    The marine auxiliary diesel engines installed in the large transoceanic ships are used in order to generate the electricity but at the same time these engines are able to produce a significant amount of the harmful exhaust gas emissions. Therefore the International Maritime Organisation (IMO) concluded an agreement, which has to control generating of gaseous emissions in maritime transport. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the auxiliary marine diesel engine during application of the experimental fuels. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel). The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Performance of a hybrid hydrogen–gasoline engine under various operating conditions

    International Nuclear Information System (INIS)

    Ji, Changwei; Wang, Shuofeng; Zhang, Bo

    2012-01-01

    Highlights: ► We develop a combustion strategy for the hybrid hydrogen–gasoline engine (HHGE). ► The HHGE produced much lower HC and CO emissions at cold start. ► The H 2 -gasoline blends were effective for improving engine performance at idle and part loads. ► The HHGE could run smoothly at lean conditions. -- Abstract: This paper proposed a new combustion strategy for the spark-ignited (SI) engines. A gasoline engine was converted into a hybrid hydrogen–gasoline engine (HHGE) by adding a hydrogen injection system and a hybrid electronic control unit. Different from the conventional gasoline and hydrogen–enriched gasoline engines, the HHGE is fueled with the pure hydrogen at cold start to produce almost zero emissions, with the hydrogen–gasoline blends at idle and part loads to further improve thermal efficiency and reduce emissions, and with the pure gasoline to ensure the engine power output at high loads. Because the HHGE is fueled with the pure gasoline at high loads and speeds, experiments are only conducted at clod start, idle and part load conditions. Since lean combustion avails the further improvement of the engine performance, the HHGE was fueled with the lean mixtures in all tests. The experimental results showed that the hybrid hydrogen–gasoline engine was started successfully with the pure hydrogen, which produced 94.7% and 99.5% reductions in HC and CO emissions within 100 s from the onset of the cold start, compared with the original gasoline engine. At an excess air ratio of 1.37 and idle conditions, indicated thermal efficiency of the 3% hydrogen–blended gasoline engine was 46.3% higher than that of the original engine. Moreover, the engine cyclic variation was eased, combustion duration was shortened and HC, CO and NOx emissions were effectively reduced for the hybrid hydrogen–gasoline engines.

  19. Engineering Encounters: Reverse Engineering

    Science.gov (United States)

    McGowan, Veronica Cassone; Ventura, Marcia; Bell, Philip

    2017-01-01

    This column presents ideas and techniques to enhance your science teaching. This month's issue shares information on how students' everyday experiences can support science learning through engineering design. In this article, the authors outline a reverse-engineering model of instruction and describe one example of how it looked in our fifth-grade…

  20. Effect of Operating Conditions on Pollutants Concentration Emitted from a Spark Ignition Engine Fueled with Gasoline Bioethanol Blends

    Directory of Open Access Journals (Sweden)

    Haroun A. K. Shahad

    2015-01-01

    Full Text Available This study is an experimental investigation of the effect of bioethanol gasoline blending on exhaust emissions in terms of carbon dioxide CO2, carbon monoxide CO, unburnt hydrocarbons UHC, and nitric oxide NOx of a spark ignition engine. Tests are conducted at controlled throttle and variable speed condition over the range of 1200 to 2000 rpm with intervals 400 rpm. Different compression ratios are tested for each speed, namely (7,8,10, and 11. Pure gasoline and bioethanol gasoline blends are used. The bioethanol used is produced from Iraqi date crop (Zehdi. Blending is done on energy replacement bases. Ethanol energy ratio (EER used is 5%, 10%, and 15%. At each of the three designated engine speeds, the torque is set as 0, 3, 7, 10, and 14 N·m. It is found that ethanol blending reduces CO and UHC concentration in the exhaust gases by about 45% and 40.15%, respectively, and increases NOx and CO2 concentrations in the exhaust gases by about 16.18% and 7.5%, respectively. It is found also that load and speed increase causes an increase in CO2 and NOx concentrations and reduces CO and UHC concentrations. It is also found that increasing the compression ratio causes the emissions of CO2 and NOx to decrease and those of CO and UHC to increase.