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Sample records for ground inlet nozzle

  1. New inlet nozzle assembly: C Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Calkin, J.F.

    1960-10-19

    The use of self-supported fuel elements in ribless Zircaloy-2 tubes at C-Reactor requires some inlet nozzle modification to allow charging of the larger overall diameter fuel pieces. A new nozzle assembly has been developed (by Equipment Development Operation -- IPD) which will allow use of the new fuel pieces and at the same time increase the reliability of the header-to-tube piping and reduce pumping power losses. Flow test data were requested for the new assembly and the results of these tests are presented herein. This report also presents a comparison of the header to tube energy losses for the various reactor inlet nozzle assemblies which are currently used on the Hanford production reactors.

  2. Sub-Alfvenic inlet boundary conditions for axisymmetric MHD nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Cassibry, J T [Propulsion Research Center, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Wu, S T [Center for Space Plasma and Aeronomy Research, University of Alabama in Huntsville, Huntsville, AL 35899 (United States)

    2007-09-07

    There are numerous electromagnetic accelerator concepts which require plasma expansion through a magnetic nozzle. If the inlet flow is slower than one or all of the outgoing characteristics, namely, the Alfven, slow and fast magnetosonic speeds, then the number of inlet conditions which could be arbitrarily specified are reduced by the number of outgoing characteristics (up to three). We derive the axisymmetric compatibility equations using the method of projected characteristics for the inlet conditions in the z-plane to assure the boundary conditions being consistent with flow properties. We make simplifications to the equations assuming that the inlet Alfven speed is much faster than the sonic and slow magnetosonic speeds. We compare results for various inlet boundary conditions, including a modified Lax-Wendroff implementation of the compatibility equations, first order extrapolation and arbitrarily specifying the inlet conditions, in order to assess the stability and accuracy of various approaches.

  3. Wall Pressure Measurements in a Convergent-Divergent Nozzle with Varying Inlet Asymmetry

    Science.gov (United States)

    Senthilkumar, C.; Elangovan, S.; Rathakrishnan, E.

    2016-06-01

    In this paper, flow separation of a convergent-divergent (C-D) nozzle is placed downstream of a supersonic flow delivered from Mach 2.0 nozzle is investigated. Static pressure measurements are conducted using pressure taps. The flow characteristics of straight and slanted entry C-D nozzle are investigated for various NPR of Mach 2.0 nozzle. The effect of asymmetry at inlet by providing 15°, 30°, 45° and 57° cut is analyzed. Particular attention is given to the location of the shock within the divergent section of the test nozzle. This location is examined as a function both NPR of Mach 2.0 nozzle and test nozzle inlet angle. Some of the measurements are favorably compared to previously developed theory. A Mach number ratio of 0.81 across the flow separation region was obtained.

  4. Performance Prediction of Darrieus-Type Hydroturbine with Inlet Nozzle Operated in Open Water Channels

    Science.gov (United States)

    Nakashima, K.; Watanabe, S.; Matsushita, D.; Tsuda, S.; Furukawa, A.

    2016-11-01

    Small hydropower is one of the renewable energies and is expected to be effectively used for local supply of electricity. We have developed Darrieus-type hydro-turbine systems, and among them, the Darrieus-turbine with a weir and a nozzle installed upstream of turbine is, so far, in success to obtain more output power by gathering all water into the turbine. However, there can several cases exist, in which installing the weir covering all the flow channel width is unrealistic, and in such cases, the turbine should be put alone in open channels without upstream weir. Since the output power is very small in such a utilization of small hydropower, it is important to derive more power for the cost reduction. In the present study, we parametrically investigate the preferable shape of the inlet nozzle for the Darrieus-type hydroturbine operated in an open flow channel. Experimental investigation is carried out in the open channel in our lab. Tested inlet nozzles are composed of two flat plates with the various nozzle converging angles and nozzle outlet (runner inlet) widths with the nozzle inlet width kept constant. As a result, the turbine with the nozzles having large converging angle and wide outlet width generates higher power. Two-dimensional unsteady numerical simulation is also carried out to qualitatively understand the flow mechanism leading to the better performance of turbine. Since the depth, the width and the flow rate in the real open flow channels are different from place to place and, in some cases from time to time, it is also important to predict the onsite performance of the hydroturbine from the lab experiment at planning stage. One-dimensional stream-tube model is developed for this purpose, in which the Darrieus-type hydroturbine with the inlet nozzle is considered as an actuator-disk modelled based on our experimental and numerical results.

  5. Suppression of Performance Curve Instability of an Axial-Flow Pump by Using a Double-Inlet-Nozzle

    Directory of Open Access Journals (Sweden)

    P. Pérez Flores

    2008-01-01

    Full Text Available It has been shown that the sudden decrease of pump head in an axial flow pump caused by stall can be overcome by means of casing treatment. Flat axial grooves in front of the impeller break the swirl of the near-casing backflow. The disadvantage of this method is strong cavitation at the inlet of the grooves for flow rates below the stall point. In this paper another improved method to stabilize the performance curve will be presented, using a double-inlet-nozzle. At the onset of stall the initial near-casing backflow with its high swirl is lead off into the gap between both nozzles. At design conditions this double-inlet-nozzle is working as an injector, supporting the near-casing-inflow. The function of the double-inlet-nozzle is demonstrated by PIV-measurements.

  6. Advanced Methods for Aircraft Engine Thrust and Noise Benefits: Nozzle-Inlet Flow Analysis

    Science.gov (United States)

    Gilinsky, Mikhail; Morgan, Morris H.; Povitsky, Alex; Schkolnikov, Natalia; Njoroge, Norman; Coston, Calvin; Blankson, Isaiah M.

    2001-01-01

    The Fluid Mechanics and Acoustics Laboratory at Hampton University (HU/FM&AL) jointly with the NASA Glenn Research Center has conducted four connected subprojects under the reporting project. Basically, the HU/FM&AL Team has been involved in joint research with the purpose of theoretical explanation of experimental facts and creation of accurate numerical simulation techniques and prediction theory for solution of current problems in propulsion systems of interest to the NAVY and NASA agencies. This work is also supported by joint research between the NASA GRC and the Institute of Mechanics at Moscow State University (IM/MSU) in Russia under a CRDF grant. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analyses for advanced aircraft and rocket engines. The FM&AL Team uses analytical methods, numerical simulations and possible experimental tests at the Hampton University campus. The fundamental idea uniting these subprojects is to use nontraditional 3D corrugated and composite nozzle and inlet designs and additional methods for exhaust jet noise reduction without essential thrust loss and even with thrust augmentation. These subprojects are: (1) Aeroperformance and acoustics of Bluebell-shaped and Telescope-shaped designs; (2) An analysis of sharp-edged nozzle exit designs for effective fuel injection into the flow stream in air-breathing engines: triangular-round, diamond-round and other nozzles; (3) Measurement technique improvement for the HU Low Speed Wind Tunnel; a new course in the field of aerodynamics, teaching and training of HU students; experimental tests of Mobius-shaped screws: research and training; (4) Supersonic inlet shape optimization. The main outcomes during this reporting period are: (l) Publications: The AIAA Paper #00-3170 was presented at the 36th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 17-19 June, 2000, Huntsville, AL. The AIAA

  7. Engine inlet distortion in a 9.2 percent scale vectored thrust STOVL model in ground effect

    Science.gov (United States)

    Johns, Albert L.; Neiner, George; Flood, J. D.; Amuedo, K. C.; Strock, T. W.

    1989-01-01

    Advanced Short Takeoff/Vertical Landing (STOVL) aircraft which can operate from remote locations, damaged runways, and small air capable ships are being pursued for deployment around the turn of the century. To achieve this goal, NASA Lewis Research Center, McDonnell Douglas Aircraft, and DARPA defined a cooperative program for testing in the NASA Lewis 9- by 15-foot low speed wind tunnel (LSWT) to establish a database for hot gas ingestion, one of the technologies critical to STOVL. Results are presented which show the engine inlet distortions (both temperature and pressure) in a 9.2 percent scale vectored thrust STOVL model in ground effects. Results are shown for the forward nozzle splay angles of 0 degrees, -6 degrees, and 18 degrees. The model support system had 4 degrees of freedom, heated high pressure air for nozzle flow, and a suction system exhaust for inlet flow. The headwind (freestream) velocity was varied from 8 to 23 knots.

  8. Engine inlet distortion in a 9.2 percent scaled vectored thrust STOVL model in ground effect

    Science.gov (United States)

    Johns, Albert L.; Neiner, George; Flood, J. D.; Amuedo, K. C.; Strock, T. W.

    1989-01-01

    Advanced Short Takeoff/Vertical Landing (STOVL) aircraft which can operate from remote locations, damaged runways, and small air capable ships are being pursued for deployment around the turn of the century. To achieve this goal, a cooperative program has been defined for testing in the NASA Lewis 9- by 15-foot Low Speed Wind Tunnel (LSWT) to establish a database for hot gas ingestion, one of the technologies critical to STOVL. This paper presents results showing the engine inlet distortions (both temperature and pressure) in a 9.2 percent scale Vectored Thrust STOVL model in ground effects. Results are shown for the forward nozzle splay angles of 0, -6, and 18 deg. The model support system had 4 deg of freedom, heated high pressure air for nozzle flow, and a suction system exhaust for inlet flow. The headwind (freestream) velocity was varied from 8 to 23 kn.

  9. Secondary flow and heat transfer control in gas turbine inlet nozzle guide vanes

    Science.gov (United States)

    Burd, Steven Wayne

    1998-12-01

    Endwall heat transfer is a very serious problem in the inlet nozzle guide vane region of gas turbine engines. To resolve heat transfer concerns and provide the desired thermal protection, modern cooling flows for the vane endwalls tend to be excessive leading to lossy and inefficient designs. Coolant introduction is further complicated by the flow patterns along vane endwall surfaces. They are three-dimensional and dominated by strong, complex secondary flows. To achieve performance goals for next-generation engines, more aerodynamically efficient and advanced cooling concepts, including combustor bleed cooling, must be investigated. To this end, the overall performance characteristics of several combustor bleed flow designs are assessed in this experimental study. In particular, their contributions toward secondary flow control and component cooling are documented. Testing is performed in a large-scale, guide vane simulator comprised of three airfoils encased between one contoured and one flat endwall. Core flow is supplied to this simulator at an inlet chord Reynolds number of 350,000 and turbulence intensity of 9.5%. Combustor bleed cooling flow is injected through the contoured endwall via inclined slots. The slots vary in cross-sectional area, have equivalent slot widths, and are positioned with their leeward edges 10% of the axial chord ahead of the airfoil leading edges. Measurements with hot-wire anemometry characterize the inlet and exit flow fields of the cascade. Total and static pressure measurements document aerodynamic performance. Thermocouple measurements detail thermal fields and permit evaluation of surface adiabatic effectiveness. To elucidate the effects of bleed injection, data are compared to an experiment taken without bleed. The influence of bleed mass flow rate and slot geometry on the aerodynamic losses and thermal protection arc given. This study suggests that such combustor bleed flow cooling offers significant thermal protection without

  10. Nozzle

    Science.gov (United States)

    Chen, Alexander G.; Cohen, Jeffrey M.

    2009-06-16

    A fuel injector has a number of groups of nozzles. The groups are generally concentric with an injector axis. Each nozzle defines a gas flowpath having an outlet for discharging a fuel/air mixture jet. There are means for introducing the fuel to the air. One or more groups of the nozzles are oriented to direct the associated jets skew to the injector axis.

  11. Evaporation level of the condensate droplets on a shock wave in the IMP PAN nozzle depending on the inlet conditions

    Science.gov (United States)

    Kornet, S.; Badur, J.

    2016-10-01

    In the present paper we have focused on the phenomena of condensate reevaporation in the shock wave zone. Having observed the finishing of a foggy flow within the shock wave, according to Puzyrewski's observations, we would like to analyse the critical inlet conditions which cause total evaporation of condensate droplets on the shock in the IMP PAN nozzle. In the paper some original mechanistic model of droplet evaporation is involved, numerically implemented and compared with the IMP PAN experiment. The single continuum model of wet steam with a special microstructure growing up during phase transitions was validated on IMP PAN experiment performed for inlet conditions close to the saturation line. The present work includes simulations results of total and partial evaporation liquid phase on the shock wave for different boundary conditions.

  12. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high speed civil aircraft will require breakthrough developments in propulsion design, including novel techniques to optimize inlet...

  13. Smart Materials Technology for High Speed Adaptive Inlet/Nozzle Design Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Enabling a new generation of high-speed civil aircraft will require breakthrough developments in propulsion systems, including novel techniques to optimize inlet...

  14. Advanced Methods for Aircraft Engine Thrust and Noise Benefits: Nozzle-Inlet Flow Analysis

    Science.gov (United States)

    Morgan, Morris H.; Gilinsky, Mikhail M.

    2001-01-01

    Three connected sub-projects were conducted under reported project. Partially, these sub-projects are directed to solving the problems conducted by the HU/FM&AL under two other NASA grants. The fundamental idea uniting these projects is to use untraditional 3D corrugated nozzle designs and additional methods for exhaust jet noise reduction without essential thrust lost and even with thrust augmentation. Such additional approaches are: (1) to add some solid, fluid, or gas mass at discrete locations to the main supersonic gas stream to minimize the negative influence of strong shock waves forming in propulsion systems; this mass addition may be accompanied by heat addition to the main stream as a result of the fuel combustion or by cooling of this stream as a result of the liquid mass evaporation and boiling; (2) to use porous or permeable nozzles and additional shells at the nozzle exit for preliminary cooling of exhaust hot jet and pressure compensation for non-design conditions (so-called continuous ejector with small mass flow rate; and (3) to propose and analyze new effective methods fuel injection into flow stream in air-breathing engines. Note that all these problems were formulated based on detailed descriptions of the main experimental facts observed at NASA Glenn Research Center. Basically, the HU/FM&AL Team has been involved in joint research with the purpose of finding theoretical explanations for experimental facts and the creation of the accurate numerical simulation technique and prediction theory for solutions for current problems in propulsion systems solved by NASA and Navy agencies. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analysis for advanced aircraft and rocket engines. The F&AL Team uses analytical methods, numerical simulations, and possible experimental tests at the Hampton University campus. We will present some management activity

  15. Exergy analysis and performance of a counter flow Ranque-Hilsch vortex tube having various nozzle numbers at different inlet pressures of oxygen and air

    Energy Technology Data Exchange (ETDEWEB)

    Kirmaci, Volkan [Bartin University, Faculty of Engineering, Mechanical Engineering Department, 74100 Bartin (Turkey)

    2009-11-15

    An experimental investigation is made to determine the effects of the orifice nozzle number and the inlet pressure on the heating and cooling performance of the counter flow Ranque-Hilsch vortex tube when air and oxygen used as a fluid. The orifices used at these experiments are made of the polyamide plastic material. The thermal conductivity of polyamide plastic material is 0.25 W/m C. Five orifices with nozzle numbers of 2, 3, 4, 5 and 6 have been manufactured and used during the experiments. For each one of the orifices (nozzle numbers) when used with two different fluids, inlet pressures were adjusted from 150 kPa to 700 kPa with 50 kPa increments, and the exergy efficiency was determined. During the experiments, a vortex tube is used with an L/D ratio of 15, and cold mass fraction is held constant at 0.5. As a result of the experimental study, it is determined that the temperature gradient between the hot and cold fluid is decreased with increasing of the orifice nozzle number. (author)

  16. Investigation of Inlet Condition Effect on Flow and Turbulence Characteristics in Subsonic Jets from Conical and Chevron Nozzles Using RANS/ILES High Resolutions Method

    Directory of Open Access Journals (Sweden)

    L. A. Benderskiy

    2015-01-01

    Full Text Available Effect of Mach number and temperature on subsonic jets flow with a combined highresolution RANS/ILES method (Reynolds Averaged Navier-Stokes - RANS, Implicit Large Eddy Simulation - ILES was investigated. Cold Mj=0.985 T0=300К and hot Mj=0.548 T0=858.6К jets were considered (Mj – Mach number at the nozzle exit and T0 – total temperature at the nozzle inlet. Conical and two chevron nozzles with angle of chevrons to the nozzle axis α=5° and α=18.2° were investigated. The jet flow calculations were carried out together with flow calculation in nozzles. Computation grids were Meshes for simulations (2.8-3.2×106 cells. Investigated cases were compared by average velocity and velocity fluctuations at the jet axis and at the mixing layer. The magnitude of velocity fluctuations at the jet axis and at the mixing layer for hot jets is higher than for cold jets. It leads to increasing expansion angle of the mixing layer inward the jet axis. This is why the initial part length of hot jets becomes shorter than in cold jets. Comparison of simulations with the experimental data of other authors showed a good agreement by flow and turbulences characteristics.

  17. Influence of the trajectory angle and nozzle height from the ground on water distribution radial curve of a sprinkler

    Directory of Open Access Journals (Sweden)

    Dario Friso

    2012-06-01

    Full Text Available In order to evaluate the effects of the variation of two factors of the working condition, the trajectory angle and the nozzle height from the ground, on the water distribution radial curve of a sprinkler, a mathematical model, able to elaborate with a very good accuracy the size spectrum of droplets generated by a nozzle starting from experimental water distribution radial curves, was used and applied in reversed form. In a previous paper, 37 dimensional droplet spectra were obtained, generated by four sprinklers under varying conditions of operating pressure and nozzle size, but with a single value of trajectory angle and a single value of the nozzle height from the ground level. The application of the mathematical model to the 37 dimensional spectra of the droplets has led to new water distribution radial curves on varying the trajectory angle and the nozzle height. The evaluation of these curves, along with original and experimental ones, has been made using the uniformity of distribution, by means of Christiansen's coefficient CU. Increasing values of pressure and nozzle size provide the best CU. This is applied to all heights of the nozzle from the ground and to almost all trajectory angle values. In all cases, different nozzle heights do not show significant differences in CU values. This also occurred in the comparison of three different trajectory angles, unless the larger diameter and lower height of the nozzle where the CU coefficient gets worse with decreasing the trajectory. The evaluation of the new water distribution radial curves was also made in relation to the produced radius of throw R (m, and it was found that R is positively influenced by all the variables involved. Considering this relationship, two monomial type equations (one for nozzle discharge up to 120 dm3/min and radius of throw less than 30 m and one for nozzle discharge above 120 dm3/min and higher throw radii were found that can predict R compared to the discharge

  18. Effect of fuel zoning and fuel nozzle design on pollution emissions at ground idle conditions for a double-annular ram-induction combustor

    Science.gov (United States)

    Clements, T. R.

    1973-01-01

    An exhaust emission survey was conducted on a double-annular ram induction combustor at simulated ground idle conditions. The combustor was designed for a large augmented turbofan engine capable of sustained flight speeds up to Mach 3.0. The emission levels of total hydrocarbon (THC), carbon monoxide, carbon dioxide, and nitric oxide were measured. The effects of fuel zoning, fuel nozzle design, and operating conditions (inlet temperature and reference Mach number) on the level of these emissions were determined. At an overall combustor fuel/air ratio of 0.007, fuel zoning reduced THC emissions by a factor of 5 to 1. The reduction in THC emissions is attributed to the increase in local fuel/air ratio provided by the fuel zoning. An alternative method of increasing fuel/air ratio would be to operate with larger-than-normal compressor overboard bleed; however, analysis on this method indicated an increase in idle fuel consumption of 20 percent. The use of air-atomizing nozzles reduced the THC emissions by 2 to 1.

  19. Side-wall effect of runner casing on performance of Darrieus-type hydro turbine with inlet nozzle for extra-low head utilization

    Institute of Scientific and Technical Information of China (English)

    Kai; SHIMOKAWA; Akinori; FURUKAWA; Kusuo; OKUMA; Daisuke; MATSUSHITA; Satoshi; WATANABE

    2010-01-01

    A ducted Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m.Though the hydro turbine system,in general,might consist of an intake,runner casing section and a draft tube for higher efficiency operation,it was clarified in previous experiment that there was no need of the side-walls of runner casing section and a draft-tube for keeping the efficiency high in the case of duct with an inlet nozzle.This would yield a simplification of the structure of the turbine system.In order to reconfirm this result for large-sized turbine with 560 mm×300 mm duct,instead of small-sized one with 400 mm×200 mm duct,the side-wall effect on turbine performance was experimentally investigated for three-or four-bladed runner.In the present paper,the experimental results are shown with considering flow behaviors in the runner section.

  20. Spiral cooled fuel nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Timothy; Schilp, Reinhard

    2012-09-25

    A fuel nozzle for delivery of fuel to a gas turbine engine. The fuel nozzle includes an outer nozzle wall and a center body located centrally within the nozzle wall. A gap is defined between an inner wall surface of the nozzle wall and an outer body surface of the center body for providing fuel flow in a longitudinal direction from an inlet end to an outlet end of the fuel nozzle. A turbulating feature is defined on at least one of the central body and the inner wall for causing at least a portion of the fuel flow in the gap to flow transverse to the longitudinal direction. The gap is effective to provide a substantially uniform temperature distribution along the nozzle wall in the circumferential direction.

  1. Numerical Simulations of Canted Nozzle and Scarfed Nozzle Flow Fields

    Science.gov (United States)

    Javed, Afroz; Chakraborty, Debasis

    2016-06-01

    Computational fluid dynamics (CFD) techniques are used for the analysis of issues concerning non-conventional (canted and scarfed) nozzle flow fields. Numerical simulations are carried out for the quality of flow in terms of axisymmetric nature at the inlet of canted nozzles of a rocket motor. Two different nozzle geometries are examined. The analysis of these simulation results shows that the flow field at the entry of the nozzles is non axisymmetric at the start of the motor. With time this asymmetry diminishes, also the flow becomes symmetric before the nozzle throat, indicating no misalignment of thrust vector with the nozzle axis. The qualitative flow fields at the inlet of the nozzles are used in selecting the geometry with lesser flow asymmetry. Further CFD methodology is used to analyse flow field of a scarfed nozzle for the evaluation of thrust developed and its direction. This work demonstrates the capability of the CFD based methods for the nozzle analysis problems which were earlier solved only approximately by making simplifying assumptions and semi empirical methods.

  2. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  3. Effect to Flow Field with Coagulator in the Inlet Nozzle of ESP%电除尘器进口封头内设置凝聚器对流场的影响

    Institute of Scientific and Technical Information of China (English)

    郦建国; 刘含笑; 姚宇平; 袁伟锋; 郭峰; 余顺利

    2014-01-01

    电凝聚技术是目前燃煤电厂P M2.5捕集增效的控制技术之一。将凝聚器设在电除尘器进口封头内,可扩大使用范围。参照某135 MW机组布置方式,利用流体动力学软件,构建几何模型并进行网格划分,分析凝聚器在第一层、第二层分布板间对气流的影响,计算进口封头内颗粒运动轨迹及湍流大小。结果表明:在电除尘器进口封头第一层、第二层分布板间设置凝聚器,能满足第一电场入口速度均匀性的要求;在第二层、第三层分布板下端,割掉0.5 m导流板,有利卸灰,但对气流均匀性影响较大;由湍流强度可知,将凝聚器设在第一层分布板前,可使荷电颗粒有更多碰撞、凝聚的概率,从而提高捕集P M2.5能力。%Electro-coagulation technology is one of the main technologies for controlling the PM2 .5 discharged from the coal-fired power plant currently.The application of coagulator can be expanded if set it in the inlet nozzle of electrostatic precipitator.In this paper,reference to the arrangement of a 135 MW unit,geometric model and meshing was done with the use of CFD software,and the effects of velocity distribution with the co-agulator arranged separately in the first and the second distribution plate ,and the particle traj ectories and tur-bulence intensity in the inlet nozzle were calculated.The results show that,it can satisfy the requirement of the velocity uniformity on the first electric field inlet with the coagulator arranged separately in the first and the second distribution plate;Cuting 0.5m guide plate under the bottom floor of second and third distribution board is good for ash removaling,while it is greater influence on the flow uniformity;On the basis of the tur-bulence intensity value,it can make the charged particles have more the probability of collision,condensation, thus improve the ability of PM2.5 capture ,with coalescer is located before the first

  4. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    Nozzle reaction and hose tension are analyzed using conservation of fluid momentum and assuming steady, inviscid flow and a flexible hose in frictionless contact with the ground. An expression that is independent of the bend angle is derived for the hose tension. If this tension is exceeded owing...... to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand...

  5. Investigation of Flow Instabilities in the Inlet Ducts of DP-1C VTOL Aircraft

    Science.gov (United States)

    Lepicovsky, Jan

    2008-01-01

    An investigation of flow instabilities in the inlet ducts of a two-engine vertical takeoff and landing aircraft DP-1C is described in this report. Recent tests revealed that the engines stall during run ups while the aircraft is operating on the ground. These pop stalls occurred at relatively low power levels, sometimes as low as 60 percent of the engine full speed. Inability to run the engines up to the full speed level is attributed to in-ground effects associated with hot gas ingestion. Such pop stalls were never experienced when the aircraft was tested on a elevated grid platform, which ensured that the aircraft was operating in out-of-the-ground-effect conditions. Based on available information on problems experienced with other vertical takeoff and landing aircraft designs, it was assumed that the engine stalls were caused by partial ingestion of hot gases streaming forward from the main exit nozzle under the aircraft inlets, which are very close to the ground. It was also suggested that the nose wheel undercarriage, located between the inlets, may generate vortices or an unstable wake causing intense mixing of hot exit gases with incoming inlet flow, which would enhance the hot gas ingestion. After running a short three-day series of tests with fully instrumented engine inlets, it is now believed the most probable reason for engine pop stalls are random ingestions of a vortex generated between the two streams moving in opposite directions: outbound hot gas stream from the main nozzle close to the ground and inbound inlet flow above. Originally, the vortex is in a horizontal plane. However, at a certain velocity ratio of these two streams, the vortex attaches either to the ground or the aircraft surface at one end and the other end is swallowed by one of the aircraft inlets. Once the vortex enters the inlet duct, a puff of hot air can be sucked through the vortex core into the engine, which causes a serious inlet flow field distortion followed by an engine

  6. External Cylindrical Nozzle with Controlled Vacuum

    Directory of Open Access Journals (Sweden)

    V. N. Pil'gunov

    2015-01-01

    Full Text Available There is a developed design of the external cylindrical nozzle with a vacuum camera. The paper studies the nozzle controllability of flow rate via regulated connection of the evacuated chamber to the atmosphere through an air throttle. Working capacity of the nozzle with inlet round or triangular orifice are researched. The gap is provided in the nozzle design between the external wall of the inlet orifice and the end face of the straight case in the nozzle case. The presented mathematical model of the nozzle with the evacuated chamber allows us to estimate the expected vacuum amount in the compressed section of a stream and maximum permissible absolute pressure at the inlet orifice. The paper gives experimental characteristics of the fluid flow process through the nozzle for different values of internal diameter of a straight case and an extent of its end face remoteness from an external wall of the inlet orifice. It estimates how geometry of nozzle constructive elements influences on the volume flow rate. It is established that the nozzle capacity significantly depends on the shape of inlet orifice. Triangular orifice nozzles steadily work in the mode of completely filled flow area of the straight case at much more amounts of the limit pressure of the flow. Vacuum depth in the evacuated chamber also depends on the shape of inlet orifice: the greatest vacuum is reached in a nozzle with the triangular orifice which 1.5 times exceeds the greatest vacuum with the round orifice. Possibility to control nozzle capacity through the regulated connection of the evacuated chamber to the atmosphere was experimentally estimated, thus depth of flow rate regulation of the nozzle with a triangular orifice was 45% in comparison with 10% regulation depth of the nozzle with a round orifice. Depth of regulation calculated by a mathematical model appeared to be much more. The paper presents experimental dependences of the flow coefficients of nozzle input orifice

  7. Scramjet Nozzles

    Science.gov (United States)

    2010-09-01

    integration et gestion thermique ) 14. ABSTRACT The lecture is given in four parts, each being a step in the process of nozzle design, and within each part...project and applied to the conceptual design of a Mach 3.5 transport aircraft. The result is depicted in figure 4. The central feature of the concept is

  8. Coastal Inlet Model Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Coastal Inlet Model Facility, as part of the Coastal Inlets Research Program (CIRP), is an idealized inlet dedicated to the study of coastal inlets and equipped...

  9. Fluid Flow in Continuous Casting Mold with a Configured Nozzle

    Institute of Scientific and Technical Information of China (English)

    王镭; 沈厚发; 柳百成

    2004-01-01

    The influence of a configured nozzle on the turbulent fluid flow in a continuous casting mold was investigated using the simulation program Visual Cast, which used the finite difference method and the SIMPLER algorithm. CAD software was used to construct the complicated nozzle in the calculational region. The simulation accuracy was validated by comparison with the classic driven cavity flow problem. The simulation results agree well with water modeling experiments. The simulations show that the velocity distribution at the nozzle port is uneven and the jet faces downward more than the nozzle outlet. Simulations with a configured nozzle and the inlet velocity at the nozzle entrance give precise results and overcome the traditional difficulty in determining the nozzle outlet velocity.

  10. Optimization of Profile and Material of Abrasive Water Jet Nozzle

    Science.gov (United States)

    Anand Bala Selwin, K. P.; Ramachandran, S.

    2017-05-01

    The objective of this work is to study the behaviour of the abrasive water jet nozzle with different profiles and materials. Taguchi-Grey relational analysis optimization technique is used to optimize the value with different material and different profiles. Initially the 3D models of the nozzle are modelled with different profiles by changing the tapered inlet angle of the nozzle. The different profile models are analysed with different materials and the results are optimized. The optimized results would give the better result taking wear and machining behaviour of the nozzle.

  11. Spray nozzle for fire control

    Science.gov (United States)

    Papavergos, Panayiotis G.

    1990-09-01

    The design of a spray nozzle for fire control is described. It produces a spray of gas and liquid having an oval transverse cross section and it comprises a mixing chamber with an oval transverse cross section adapted to induce a toroidal mixing pattern in pressurized gas and liquid introduced to the mixing chamber through a plurality of inlets. In a preferred embodiment the mixing chamber is toroidal. The spray nozzle produces an oval spray pattern for more efficient wetting of narrow passages and is suitable for fire control systems in vehicles or other confined spaces. Vehicles to which this invention may be applied include trains, armoured vehicles, ships, hovercraft, submarines, oil rigs, and most preferably, aircraft.

  12. Gas only nozzle

    Science.gov (United States)

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  13. A review on nozzle wear in abrasive water jet machining application

    Science.gov (United States)

    Syazwani, H.; Mebrahitom, G.; Azmir, A.

    2016-02-01

    This paper discusses a review on nozzle wear in abrasive water jet machining application. Wear of the nozzle becomes a major problem since it may affect the water jet machining performance. Design, materials, and life of the nozzle give significance effect to the nozzle wear. There are various parameters that may influence the wear rate of the nozzle such as nozzle length, nozzle inlet angle, nozzle diameter, orifice diameter, abrasive flow rate and water pressure. The wear rate of the nozzle can be minimized by controlling these parameters. The mechanism of wear in the nozzle is similar to other traditional machining processes which uses a cutting tool. The high pressure of the water and hard abrasive particles may erode the nozzle wall. A new nozzle using a tungsten carbide-based material has been developed to reduce the wear rate and improve the nozzle life. Apart from that, prevention of the nozzle wear has been achieved using porous lubricated nozzle. This paper presents a comprehensive review about the wear of abrasive water jet nozzle.

  14. Combustor nozzles in gas turbine engines

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Thomas Edward; Keener, Christopher Paul; Stewart, Jason Thurman; Ostebee, Heath Michael

    2017-09-12

    A micro-mixer nozzle for use in a combustor of a combustion turbine engine, the micro-mixer nozzle including: a fuel plenum defined by a shroud wall connecting a periphery of a forward tube sheet to a periphery of an aft tubesheet; a plurality of mixing tubes extending across the fuel plenum for mixing a supply of compressed air and fuel, each of the mixing tubes forming a passageway between an inlet formed through the forward tubesheet and an outlet formed through the aft tubesheet; and a wall mixing tube formed in the shroud wall.

  15. Details of Side Load Test Data and Analysis for a Truncated Ideal Contour Nozzle and a Parabolic Contour Nozzle

    Science.gov (United States)

    Ruf, Joseph H.; McDaniels, David M.; Brown, Andrew M.

    2010-01-01

    Two cold flow subscale nozzles were tested for side load characteristics during simulated nozzle start transients. The two test article contours were a truncated ideal and a parabolic. The current paper is an extension of a 2009 AIAA JPC paper on the test results for the same two nozzle test articles. The side load moments were measured with the strain tube approach in MSFC s Nozzle Test Facility. The processing techniques implemented to convert the strain gage signals into side load moment data are explained. Nozzle wall pressure profiles for separated nozzle flow at many NPRs are presented and discussed in detail. The effect of the test cell diffuser inlet on the parabolic nozzle s wall pressure profiles for separated flow is shown. The maximum measured side load moments for the two contours are compared. The truncated ideal contour s peak side load moment was 45% of that of the parabolic contour. The calculated side load moments, via mean-plus-three-standard-deviations at each nozzle pressure ratio, reproduced the characteristics and absolute values of measured maximums for both contours. The effect of facility vibration on the measured side load moments is quantified and the effect on uncertainty is calculated. The nozzle contour designs are discussed and the impact of a minor fabrication flaw in the nozzle contours is explained.

  16. Discharge coefficient of small sonic nozzles

    Directory of Open Access Journals (Sweden)

    Yin Zhao-Qin

    2014-01-01

    Full Text Available The purpose of this investigation is to understand flow characteristics in mini/micro sonic nozzles, in order to precisely measure and control miniscule flowrates. Experimental and numerical simulation methods have been used to study critical flow Venturi nozzles. The results show that the nozzle’s size and shape influence gas flow characteristics which leading the boundary layer thickness to change, and then impact on the discharge coefficient. With the diameter of sonic nozzle throat decreasing, the discharge coefficient reduces. The maximum discharge coefficient exits in the condition of the inlet surface radius being double the throat diameter. The longer the diffuser section, the smaller the discharge coefficient becomes. Diffuser angle affects the discharge coefficient slightly.

  17. Cold spray nozzle design

    Science.gov (United States)

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  18. Computational Fluid Dynamics Analysis of Nozzle in Abrasive Water Jet Machining

    Science.gov (United States)

    Venugopal, S.; Chandresekaran, M.; Muthuraman, V.; Sathish, S.

    2017-03-01

    Abrasive water jet cutting is one of the most recently developed non-traditional manufacturing technologies. The general nature of flow through the machining, results in rapid wear of the nozzle which decrease the cutting performance. It is well known that the inlet pressure of the abrasive water suspension has main effect on the erosion characteristics of the inner surface of the nozzle. The objective of the project is to analyze the effect of inlet pressure on wall shear and exit kinetic energy. The analysis would be carried out by varying the inlet pressure of the nozzle, so as to obtain optimized process parameters for minimum nozzle wear. The two phase flow analysis would be carried by using computational fluid dynamics tool CFX. The availability of minimized process parameters such as of abrasive water jet machining (AWJM) is limited to water and experimental test can be cost prohibitive.

  19. Radical recombination in a hydrocarbon-fueled scramjet nozzle

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoyuan

    2014-12-01

    Full Text Available To reveal the radical recombination process in the scramjet nozzle flow and study the effects of various factors of the recombination, weighted essentially non-oscillatory (WENO schemes are applied to solve the decoupled two-dimensional Euler equations with chemical reactions to simulate the hydrocarbon-fueled scramjet nozzle flow. The accuracy of the numerical method is verified with the measurements obtained by a shock tunnel experiment. The overall model length is nearly 0.5 m, with inlet static temperatures ranging from 2000 K to 3000 K, inlet static pressures ranging from 75 kPa to 175 kPa, and inlet Mach numbers of 2.0 ± 0.4 are involved. The fraction Damkohler number is defined as functions of static temperature and pressure to analyze the radical recombination progresses. Preliminary results indicate that the energy releasing process depends on different chemical reaction processes and species group contributions. In hydrocarbon-fueled scramjet nozzle flow, reactions with H have the greatest contribution during the chemical equilibrium shift. The contrast and analysis of the simulation results show that the radical recombination processes influenced by inflow conditions and nozzle scales are consistent with Damkohler numbers and potential dissociation energy release. The increase of inlet static temperature improves both of them, thus making the chemical non-equilibrium effects on the nozzle performance more significant. While the increase of inlet static pressure improves the former one and reduces the latter, it exerts little influence on the chemical non-equilibrium effects.

  20. Low NOx nozzle tip for a pulverized solid fuel furnace

    Science.gov (United States)

    Donais, Richard E; Hellewell, Todd D; Lewis, Robert D; Richards, Galen H; Towle, David P

    2014-04-22

    A nozzle tip [100] for a pulverized solid fuel pipe nozzle [200] of a pulverized solid fuel-fired furnace includes: a primary air shroud [120] having an inlet [102] and an outlet [104], wherein the inlet [102] receives a fuel flow [230]; and a flow splitter [180] disposed within the primary air shroud [120], wherein the flow splitter disperses particles in the fuel flow [230] to the outlet [104] to provide a fuel flow jet which reduces NOx in the pulverized solid fuel-fired furnace. In alternative embodiments, the flow splitter [180] may be wedge shaped and extend partially or entirely across the outlet [104]. In another alternative embodiment, flow splitter [180] may be moved forward toward the inlet [102] to create a recessed design.

  1. Reaction thrust of water jet for conical nozzles

    Institute of Scientific and Technical Information of China (English)

    HUANG Guo-qin; YANG You-sheng; LI Xiao-hui; ZHU Yu-quan

    2009-01-01

    Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system.In this paper,theoretical,numerical and experimental studies were carried out to investigate the effects of the nozzle geometry as well as the inlet conditions on the reaction thrust of water jet.Comparison analyses reveal that the reaction thrust has a direct proportional relationship with the product of the inlet pressure,the square of flow rate and two-thirds power exponent of the input power.The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence on the reaction thrust characteristics.In addition,the best values of the half cone angle and the cylinder column length exist to make the reaction thrust reach its maximum under the same inlet conditions.

  2. INLET STRATIFICATION DEVICE

    DEFF Research Database (Denmark)

    2006-01-01

    An inlet stratification device (5) for a circuit circulating a fluid through a tank (1 ) and for providing and maintaining stratification of the fluid in the tank (1 ). The stratification de- vice (5) is arranged vertically in the tank (1) and comprises an inlet pipe (6) being at least partially...... formed of a flexible porous material and having an inlet (19) and outlets formed of the pores of the porous material. The stratification device (5) further comprises at least one outer pipe (7) surrounding the inlet pipe (6) in spaced relationship thereto and being at least partially formed of a porous...

  3. Safety analysis on large partial inlet flow blockage in PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, J.; Chang, W. P.; Jeong, J. H.; Ha, K. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The objective of the present study is to predict cladding temperature for the hot assembly by postulating flow blockage accident occurring side orifice nozzles at lower plenum. The large partial inlet flow blockage occurring orifice nozzles of receptacle was estimated by MATRA-LMR/FB. It is hypothesized that a large object has gotten down to lower plenum during normal operation and blocked side orifice nozzles at lower plenum. The flow blockage has been considered one of the main issues to be addressed in SFR since the Ferim-1 suffered a partial fuel meltdown. The flow blockage causes an insufficient amount of coolant to enter the fuel assembly. Large Partial Inlet flow blockage is classified as DEC (Design Extension Condition) for PGSFR. There are several flow paths at lower plenum and possibility of occurrence of inlet flow blockage is estimated to be about 1 x 10{sup -8} which is very remote. However, it should be dealt with in PGSFR because it is a BE (Bounding Event). There are no known sources for inlet flow blockage but one could postulate that a large object might be gotten down to lower plenum during normal operation. Then it leads to not only reduced flow rate that flows into assemblies but also temperature increase within fuel assembly. The results indicate that 3-orifice nozzles blockage (50% of blockage area) lead to a maximum clad temperature of inner/outer core assembly around 670 .deg. C/580 .deg. C. This is guaranteed that safety margin is enough considering the eutectic temperature. On the other hand, for more than 4-orifice nozzles blockage (67% of blockage area), the maximum clad temperature of both inner/outer core assembly reaches around 806 .deg. C/739 .deg. C, respectively, which go beyond eutectic temperature.

  4. Gas only nozzle fuel tip

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, William Theodore (Scotia, NY); Fitts, David Orus (Ballston Spa, NY); DeLeonardo, Guy Wayne (Glenville, NY)

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  5. Inlet stratification device

    DEFF Research Database (Denmark)

    2014-01-01

    ) with an inlet passage way (16). The upper end of the inlet pipe (6) is connected with a top cap (9). The top cap (9) and the bottom cap (10) are mutually connected by means of a wire (8) and the top cap (9) is configured as a floating device providing a buoyancy force larger than the downwardly directed force......An inlet stratification (5) is adapted to be arranged vertically in a tank (1) during operation. The stratification device (5) comprises an inlet pipe (6) formed of a flexible porous material and having a lower and upper end. The lower end of the inlet pipe (6) is connected to a bottom cap (10...

  6. Thermal-Hydraulic Performance of Scrubbing Nozzle Used for CFVS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Chul; Lee, Doo Yong; Jung, Woo Young; Lee, Jong Chan; Kim, Gyu Tae [FNC TECH, Yongin (Korea, Republic of)

    2016-05-15

    A Containment Filtered Venting System (CFVS) is the most interested device to mitigate a threat against containment integrity under the severe accident of nuclear power plant by venting with the filtration of the fission products. FNC technology and partners have been developed the self-priming scrubbing nozzle used for the CFVS which is based on the venturi effect. The thermal-hydraulic performances such as passive scrubbing water suction as well as pressure drop across the nozzle have been tested under various thermal-hydraulic conditions. The two types of test section have been built for testing the thermal-hydraulic performance of the self-priming scrubbing nozzle. Through the visualization loop, the liquid suction performance through the slit, pressure drop across the nozzle are measured. The passive water suction flow through the suction slit at the throat is important parameter to define the scrubbing performance of the self-priming scrubbing nozzle. The water suction flow is increased with the increase of the overhead water level at the same inlet gas flow. It is not so much changed with the change of inlet gas flow at the overhead water level.

  7. Rapidly design safety relief valve inlet piping systems

    Energy Technology Data Exchange (ETDEWEB)

    Westman, M.A.

    1997-03-01

    Safety relief valves (SRVs) used to protect against overpressure require well-designed inlet piping for proper operation. The engineer`s job is to produce these designs from a thorough understanding of the inlet piping as a key component in the safety relief system and the correct application of the governing fluid dynamics principles. This article will present a technique for analysis and design using classical ideal-gas adiabatic fluid flow principles. Also, it will discuss the advantages of using the personal computer (PC) to quickly arrive at accurate designs. This work applies to SRVs in which relief flows are limited by sonic conditions at their nozzles.

  8. Transition nozzle combustion system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Maldonado, Jaime Javier

    2016-11-29

    The present application provides a combustion system for use with a cooling flow. The combustion system may include a head end, an aft end, a transition nozzle extending from the head end to the aft end, and an impingement sleeve surrounding the transition nozzle. The impingement sleeve may define a first cavity in communication with the head end for a first portion of the cooling flow and a second cavity in communication with the aft end for a second portion of the cooling flow. The transition nozzle may include a number of cooling holes thereon in communication with the second portion of the cooling flow.

  9. Wear characterization of abrasive waterjet nozzles and nozzle materials

    Science.gov (United States)

    Nanduri, Madhusarathi

    Parameters that influence nozzle wear in the abrasive water jet (AWJ) environment were identified and classified into nozzle geometric, AWJ system, and nozzle material categories. Regular and accelerated wear test procedures were developed to study nozzle wear under actual and simulated conditions, respectively. Long term tests, using garnet abrasive, were conducted to validate the accelerated test procedure. In addition to exit diameter growth, two new measures of wear, nozzle weight loss and nozzle bore profiles were shown to be invaluable in characterizing and explaining the phenomena of nozzle wear. By conducting nozzle wear tests, the effects of nozzle geometric, and AWJ system parameters on nozzle wear were systematically investigated. An empirical model was developed for nozzle weight loss rate. To understand the response of nozzle materials under varying AWJ system conditions, erosion tests were conducted on samples of typical nozzle materials. The effect of factors such as jet impingement angle, abrasive type, abrasive size, abrasive flow rate, water pressure, traverse speed, and target material was evaluated. Scanning electron microscopy was performed on eroded samples as well as worn nozzles to understand the wear mechanisms. The dominant wear mechanism observed was grain pullout. Erosion models were reviewed and along the lines of classical erosion theories a semi-empirical model, suitable for erosion of nozzle materials under AWJ impact, was developed. The erosion data correlated very well with the developed model. Finally, the cutting efficiency of AWJ nozzles was investigated in conjunction with nozzle wear. The cutting efficiency of a nozzle deteriorates as it wears. There is a direct correlation between nozzle wear and cutting efficiency. The operating conditions that produce the most efficient jets also cause the most wear in the nozzle.

  10. Metal atomization spray nozzle

    Science.gov (United States)

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  11. Transonic swirling nozzle flow

    Science.gov (United States)

    Keith, Theo G., Jr.; Pawlas, Gary E.

    1991-06-01

    A numerical model of viscous transonic swirling flow in axisymmetric nozzles is developed. MacCormack's implicit Gauss-Seidel method is applied to the thin-layer Navier-Stokes equations in transformed coordinates. Numerical results are compared with experimental data to validate the method. The effect of swirl and viscosity on nozzle performance are demonstrated by examining wall pressures, Mach contours, and integral parameters.

  12. Advanced Scavenge Systems for an Integrated Engine Inlet Particle Separator

    Science.gov (United States)

    1977-09-01

    Fully machined centerbody and outer casing. Four strut (. 093 nch constant thickless. were silver - soldered to form the assembly. AIR SPLITTER ASSEMBLY...pieces of ice, nominally 1/2-inch cubes, weee introduced a.s well. In order that some degree of randomness be present, the objects were directed, unde...section (. 125-inch orifice/ •415-in. duct) followed by a high-pressure manifold to which the nozzle is silver brazed. In the secondary duct, an inlet

  13. Inlet Flux Influence to Aerodynamic Performance of Steam Turbine Vane Cascade

    OpenAIRE

    Feng Zi-Ming; Ding Huanhuan; Li Chunhong; Xu Ping

    2014-01-01

    In order to improve the aerodynamic performance and the performance of off-design working condition, it is necessary to research the inlet flow rate influence to overall performance of steam turbine. This study uses CFD technology to numerical simulation the flow field of nozzle cascades passage at 80, 100, 120% flow rate, respectively. The simulation results indicates that the various flow loss of nozzle have a little change at 100% design working condition, have decreased at 80% design work...

  14. 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.

  15. Performance of Several Conical Convergent-Divergent Rocket-Type Exhaust Nozzles

    Science.gov (United States)

    Campbell, C. E.; Farley, J. M.

    1960-01-01

    An investigation was conducted to obtain nozzle performance data with relatively large-scale models at pressure ratios as high as 120. Conical convergent-divergent nozzles with divergence angles alpha of 15, 25, and 29 deg. were each tested at area ratios of approximately 10, 25, and 40. Heated air (1200 F) was supplied at the nozzle inlet at pressures up to 145 pounds per square inch absolute and was exhausted into quiescent air at pressures as low as 1.2 pounds per square inch absolute. Thrust ratios for all nozzle configurations are presented over the range of pressure ratios attainable and were extrapolated when possible to design pressure ratio and beyond. Design thrust ratios decreased with increasing nozzle divergence angle according to the trend predicted by the (1 + cos alpha)/2 parameter. Decreasing the nozzle divergence angle resulted in sizable increases in thrust ratio for a given surface-area ratio (nozzle weight), particularly at low nozzle pressure ratios. Correlations of the nozzle static pressure at separation and of the average static pressure downstream of separation with various nozzle parameters permitted the calculation of thrust in the separated-flow region from unseparated static-pressure distributions. Thrust ratios calculated by this method agreed with measured values within about 1 percent.

  16. SINGLE PHASE ANALYTICAL MODELS FOR TERRY TURBINE NOZZLE

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua; Zhang, Hongbin; Zou, Ling; O' Brien, James

    2016-11-01

    All BWR RCIC (Reactor Core Isolation Cooling) systems and PWR AFW (Auxiliary Feed Water) systems use Terry turbine, which is composed of the wheel with turbine buckets and several groups of fixed nozzles and reversing chambers inside the turbine casing. The inlet steam is accelerated through the turbine nozzle and impacts on the wheel buckets, generating work to drive the RCIC pump. As part of the efforts to understand the unexpected “self-regulating” mode of the RCIC systems in Fukushima accidents and extend BWR RCIC and PWR AFW operational range and flexibility, mechanistic models for the Terry turbine, based on Sandia National Laboratories’ original work, has been developed and implemented in the RELAP-7 code to simulate the RCIC system. RELAP-7 is a new reactor system code currently under development with the funding support from U.S. Department of Energy. The RELAP-7 code is a fully implicit code and the preconditioned Jacobian-free Newton-Krylov (JFNK) method is used to solve the discretized nonlinear system. This paper presents a set of analytical models for simulating the flow through the Terry turbine nozzles when inlet fluid is pure steam. The implementation of the models into RELAP-7 will be briefly discussed. In the Sandia model, the turbine bucket inlet velocity is provided according to a reduced-order model, which was obtained from a large number of CFD simulations. In this work, we propose an alternative method, using an under-expanded jet model to obtain the velocity and thermodynamic conditions for the turbine bucket inlet. The models include both adiabatic expansion process inside the nozzle and free expansion process out of the nozzle to reach the ambient pressure. The combined models are able to predict the steam mass flow rate and supersonic velocity to the Terry turbine bucket entrance, which are the necessary input conditions for the Terry Turbine rotor model. The nozzle analytical models were validated with experimental data and

  17. Critical flow and pressure ratio data for LOX flowing through nozzles

    Science.gov (United States)

    Hendricks, R. C.; Simoneau, R. J.; Barrows, R. F.

    1975-01-01

    LOX and LN2 data for two-phase critical flow through nozzles have been acquired with precision control. The principal measured parameters were inlet conditions, critical flow rate and critical flow pressure ratio. The data conclusively demonstrate that the principle of corresponding states can be applied to two-phase choked flow through nozzles. These data also demonstrate that the proper normalizing parameters have been developed and current theories can provide an adequate means for extrapolating to other fluids.

  18. Three-dimensional analysis of internal flow characteristics in the injection nozzle tip of direct-injection diesel engines; Sanjigen suchi kaiseki ni yoru DI diesel kikan no nenryo funsha nozzle nai ryudo tokusei no kaimei

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, H.; Matsui, Y.; Kimura, S. [Nissan Motor Co. Ltd. Tokyo (Japan)

    1997-10-01

    To reduce the exhaust emissions and fuel consumption of direct-injection diesel engines, it is essential to optimize the fuel injection equipment closely related to combustion and emission characteristics. In this study, three-dimensional computation has been applied to investigate the effects of the injection nozzle specifications (e.g., sac volume, round shape at the inlet of the nozzle hole) and needle tip deviation on internal flow characteristics. The computational results revealed that the effects of the nozzle specifications and needle tip deviation with a smaller needle lift on internal flow characteristics and a general approach to optimize the injection nozzle specifications were obtained. 3 refs., 10 figs., 1 tab.

  19. Esophageal Inlet Patch

    Directory of Open Access Journals (Sweden)

    C. Behrens

    2011-01-01

    Full Text Available An inlet patch is a congenital anomaly consisting of ectopic gastric mucosa at or just distal to the upper esophageal sphincter. Most inlet patches are largely asymptomatic, but in problematic cases complications related to acid secretion such as esophagitis, ulcer, web and stricture may occur. The diagnosis of inlet patch is strongly suggested on barium swallow where the most common pattern consists of two small indentations on the wall of the esophagus. The diagnosis of inlet patch is confirmed via endoscopy with biopsy. At endoscopy, the lesion appears salmon-coloured and velvety and is easily distinguished from the normal grey-white squamous epithelium of the esophagus. The prominent margins correlate with the radiological findings of indentations and rim-like shadows on barium swallow. Histopathology provides the definitive diagnosis by demonstrating gastric mucosa adjacent to normal esophageal mucosa. No treatment is required for asymptomatic inlet patches. Symptomatic cases are treated with proton pump inhibitors to relieve symptoms related to acid secretion. Strictures and webs are treated with serial dilatation and should be biopsied to rule out malignancy.

  20. Numerical Optimization of converging diverging miniature cavitating nozzles

    Science.gov (United States)

    Chavan, Kanchan; Bhingole, B.; Raut, J.; Pandit, A. B.

    2015-12-01

    The work focuses on the numerical optimization of converging diverging cavitating nozzles through nozzle dimensions and wall shape. The objective is to develop design rules for the geometry of cavitating nozzles for desired end-use. Two main aspects of nozzle design which affects the cavitation have been studied i.e. end dimensions of the geometry (i.e. angle and/or curvature of the inlet, outlet and the throat and the lengths of the converging and diverging sections) and wall curvatures(concave or convex). Angle of convergence at the inlet was found to control the cavity growth whereas angle of divergence of the exit controls the collapse of cavity. CFD simulations were carried out for the straight line converging and diverging sections by varying converging and diverging angles to study its effect on the collapse pressure generated by the cavity. Optimized geometry configurations were obtained on the basis of maximum Cavitational Efficacy Ratio (CER)i.e. cavity collapse pressure generated for a given permanent pressure drop across the system. With increasing capabilities in machining and fabrication, it is possible to exploit the effect of wall curvature to create nozzles with further increase in the CER. Effect of wall curvature has been studied for the straight, concave and convex shapes. Curvature has been varied and effect of concave and convex wall curvatures vis-à-vis straight walls studied for fixed converging and diverging angles.It is concluded that concave converging-diverging nozzles with converging angle of 20° and diverging angle of 5° with the radius of curvature 0.03 m and 0.1530 m respectively gives maximum CER. Preliminary experiments using optimized geometry are indicating similar trends and are currently being carried out. Refinements of the CFD technique using two phase flow simulations are planned.

  1. Control of Surge in Centrifugal Compressor by Using a Nozzle Injection System: Universality in Optimal Position of Injection Nozzle

    Directory of Open Access Journals (Sweden)

    Toshiyuki Hirano

    2012-01-01

    Full Text Available The passive control method for surge and rotating stall in centrifugal compressors by using a nozzle injection system was proposed to extend the stable operating range to the low flow rate. A part of the flow at the scroll outlet of a compressor was recirculated to an injection nozzle installed on the inner wall of the suction pipe of the compressor through the bypass pipe and injected to the impeller inlet. Two types of compressors were tested at the rotational speeds of 50,000 rpm and 60,000 rpm with the parameter of the circumferential position of the injection nozzle. The present experimental results revealed that the optimum circumferential position, which most effectively reduced the flow rate for the surge inception, existed at the opposite side of the tongue of the scroll against the rotational axis and did not depend on the compressor system and the rotational speeds.

  2. Nozzle fabrication technique

    Science.gov (United States)

    Wells, Dennis L. (Inventor)

    1988-01-01

    This invention relates to techniques for fabricating hour glass throat or convergent divergent nozzle shapes, and more particularly to new and improved techniques for forming rocket nozzles from electrically conductive material and forming cooling channels in the wall thereof. The concept of positioning a block of electrically conductive material so that its axis is set at a predetermined skew angle with relation to a travelling electron discharge machine electrode and thereafter revolving the body about its own axis to generate a hyperbolic surface of revolution, either internal or external is novel. The method will generate a rocket nozzle which may be provided with cooling channels using the same control and positioning system. The configuration of the cooling channels so produced are unique and novel. Also the method is adaptable to nonmetallic material using analogous cutting tools, such as, water jet, laser, abrasive wire and hot wire.

  3. Flame Interactions and Thermoacoustics in Multiple-Nozzle Combustors

    Science.gov (United States)

    Dolan, Brian

    between the two nozzles. A decrease in inter-nozzle spacing resulted in a penalty to the lean blowout point and NO X emissions. Particle image velocimetry shows that the nozzle spacing also has an important effect on the flowfield of the nozzles including the shape of the recirculation region and the quantitative flow velocities. In particular, interaction in the tangential velocity between the two nozzles has large effects on the swirl number and the recirculation zone. Numerical simulations of the isothermal airflows of two pilot nozzles are validated using experimental measurements and used to provide flowfield information outside of the measurement domain. At wider inter-nozzle spacings under certain reacting conditions, an alternating flow pattern develops in the combustion chamber. The shear layers of one nozzle extent into the combustion chamber whereas the inlet reactants from the other nozzle attach near the dome wall to create a very wide recirculation region. Combustion properties, including the fuel type, are shown experimentally to affect whether or not a system will develop an alternating pattern. Simplified computational models of two interacting swirling flows are used to parametrically study the effects of nozzle exit geometry and swirl number on an alternating pattern. Both parameters are shown to be potential drivers of an alternating pattern under some conditions. A hypothesis that proposes a physical mechanism explaining the alternating flow pattern, consistent with the work in this proposal and the research of other groups, is presented. When the nozzle design, flow, or combustion characteristics cause the shear layers of the adjacent nozzles to become sufficiently opposite in direction, the two flows can no longer mix. Instead, one shear layer goes underneath the other which results in the differing flow features of the adjacent nozzles.

  4. Aerosol Scrubbing Performance Test for Self-Priming Scrubbing Nozzle Submerged in Water Pool

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Doo Yong; Jung, Woo Young; Lee, Hyun Chul; Lee, Jong Chan; Kim, Gyu Tae; Song, Yong Jae [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    A scrubbing nozzle is one of the key components for a wet scrubber process based Containment Filtered Venting System (CFVS). As a part of a development of Korean CFVS, a self-priming scrubbing nozzle shown in Fig. 1 has been developed based on the well-known venturi scrubber concept. The thermal-hydraulic performances such as the pressure drop across the nozzle, water suction behavior and droplet generation inside throat have been tested in the non-submerged condition as well as submerged condition. The self-priming scrubbing nozzle used for the wet scrubber based CFVS has been developed, which is submerged in the water pool. When there is gas flow at the inlet of the nozzle, the pool water is passively sucked from the water suction slit. The fine droplets generated inside the throat capture the aerosol particles and is discharged into the water pool. In the water pool, the pool scrubbing happens. The aerosol scrubbing performance tests for the developed self-priming scrubbing nozzle has been conducted under the operational conditions such as different aerosol sizes, different carrier gas steam fractions, different, different pool water level and nozzle inlet pressure. The major findings are as follows. (1) Aerosol scrubbing efficiency increases with the increase of the aerosol size. (2) Aerosol scrubbing efficiency increases with the increase of the carrier gas steam fraction. (3) Aerosol scrubbing.

  5. Computational fluid dynamics based aerodynamic optimization of the wind tunnel primary nozzle

    Science.gov (United States)

    Jan, Kolář; Václav, Dvořák

    2012-06-01

    The aerodynamic shape optimization of the supersonic flat nozzle is the aim of proposed paper. The nozzle discussed, is applied as a primary nozzle of the inlet part of supersonic wind tunnel. Supersonic nozzles of the measure area inlet parts need to guarantee several requirements of flow properties and quality. Mach number and minimal differences between real and required velocity and turbulence profiles at the nozzle exit are the most important parameters to meet. The aerodynamic shape optimization of the flat 2D nozzle in Computational Fluid Dynamics (CFD) is employed to reach as uniform exit velocity profile as possible, with the mean Mach number 1.4. Optimization process does not use any of standard routines of global or local optimum searching. Instead, newly formed routine, which exploits shape-based oriented sequence of nozzles, is used to research within whole discretized parametric space. The movement within optimization process is not driven by gradient or evolutionary too, instead, the Path of Minimal Shape Deformation is followed. Dynamic mesh approach is used to deform the shape and mesh from the actual nozzle to the subsequent one. Dynamic deformation of mesh allows to speed up whole converging process as an initialization of flow at the newly formed mesh is based on afore-computed shape. Shape-based similarity query in field of supersonic nozzles is discussed and applied. Evolutionary technique with genetic algorithm is used to search for minimal deformational path. As a result, the best variant from the set of solved shapes is analyzed at the base of momentum coefficient and desired Mach number at the nozzle exit.

  6. Application of shape-based similarity query for aerodynamic optimization of wind tunnel primary nozzle

    Directory of Open Access Journals (Sweden)

    Kolář Jan

    2012-04-01

    Full Text Available The aerodynamic shape optimization of the supersonic flat nozzle is the aim of proposed paper. The nozzle discussed, is applied as a primary nozzle of the inlet part of supersonic wind tunnel. Supersonic nozzles of the measure area inlet parts need to guarantee several requirements of flow properties and quality. Mach number and minimal differences between real and required velocity and turbulence profiles at the nozzle exit are the most important parameters to meet. The aerodynamic shape optimization of the flat 2D nozzle in CFD is employed to reach as uniform exit velocity profile as possible, with the mean Mach number 1.4. Optimization process does not use any of standard routines of global or local optimum searching. Instead, newly formed routine, which exploits shape-based oriented sequence of nozzles, is used to research within whole discretized parametric space. The movement within optimization process is not driven by gradient or evolutionary too, instead, the Path of Minimal Shape Deformation is followed. Dynamic mesh approach is used to deform the shape and mesh from the actual nozzle to the subsequent one. Dynamic deformation of mesh allows to speed up whole converging process as an initialization of flow at the newly formed mesh is based on afore-computed shape. Shape-based similarity query in field of supersonic nozzles is discussed and applied. Evolutionary technique with genetic algorithm is used to search for minimal deformational path. As a result, the best variant from the set of solved shapes is analyzed at the base of momentum coefficient and desired Mach number at the nozzle exit.

  7. Application of shape-based similarity query for aerodynamic optimization of wind tunnel primary nozzle

    Science.gov (United States)

    Kolář, Jan

    2012-04-01

    The aerodynamic shape optimization of the supersonic flat nozzle is the aim of proposed paper. The nozzle discussed, is applied as a primary nozzle of the inlet part of supersonic wind tunnel. Supersonic nozzles of the measure area inlet parts need to guarantee several requirements of flow properties and quality. Mach number and minimal differences between real and required velocity and turbulence profiles at the nozzle exit are the most important parameters to meet. The aerodynamic shape optimization of the flat 2D nozzle in CFD is employed to reach as uniform exit velocity profile as possible, with the mean Mach number 1.4. Optimization process does not use any of standard routines of global or local optimum searching. Instead, newly formed routine, which exploits shape-based oriented sequence of nozzles, is used to research within whole discretized parametric space. The movement within optimization process is not driven by gradient or evolutionary too, instead, the Path of Minimal Shape Deformation is followed. Dynamic mesh approach is used to deform the shape and mesh from the actual nozzle to the subsequent one. Dynamic deformation of mesh allows to speed up whole converging process as an initialization of flow at the newly formed mesh is based on afore-computed shape. Shape-based similarity query in field of supersonic nozzles is discussed and applied. Evolutionary technique with genetic algorithm is used to search for minimal deformational path. As a result, the best variant from the set of solved shapes is analyzed at the base of momentum coefficient and desired Mach number at the nozzle exit.

  8. The TICTOP nozzle: a new nozzle contouring concept

    Science.gov (United States)

    Frey, Manuel; Makowka, Konrad; Aichner, Thomas

    2016-10-01

    Currently, mainly two types of nozzle contouring methods are applied in space propulsion: the truncated ideal contour (TIC) and the thrust-optimized parabola (TOP). This article presents a new nozzle contouring method called TICTOP, combining elements of TIC and TOP design. The resulting nozzle is shock-free as the TIC and therefore does not induce restricted shock separation leading to excessive side-loads. Simultaneously, the TICTOP nozzle will allow higher nozzle wall exit pressures and hence give a better separation margin than is the case for a TIC. Hence, this new nozzle type combines the good properties of TIC and TOP nozzles and eliminates their drawbacks. It is especially suited for first stage application in launchers where flow separation and side-loads are design drivers.

  9. Fuel density effect on near nozzle flow field in small laminar coflow diffusion flames

    KAUST Repository

    Xiong, Yuan

    2015-01-01

    Flow characteristics in small coflow diffusion flames were investigated with a particular focus on the near-nozzle region and on the buoyancy force exerted on fuels with densities lighter and heavier than air (methane, ethylene, propane, and n-butane). The flow-fields were visualized through the trajectories of seed particles. The particle image velocimetry technique was also adopted for quantitative velocity field measurements. The results showed that the buoyancy force exerted on the fuel as well as on burnt gas significantly distorted the near-nozzle flow-fields. In the fuels with densities heavier than air, recirculation zones were formed very close to the nozzle, emphasizing the importance of the relative density of the fuel to that of the air on the flow-field. Nozzle heating influenced the near-nozzle flow-field particularly among lighter fuels (methane and ethylene). Numerical simulations were also conducted, focusing specifically on the effect of specifying inlet boundary conditions for fuel. The results showed that a fuel inlet boundary with a fully developed velocity profile for cases with long tubes should be specified inside the fuel tube to permit satisfactory prediction of the flow-field. The calculated temperature fields also indicated the importance of the selection of the location of the inlet boundary, especially in testing various combustion models that include soot in small coflow diffusion flames. © 2014 The Combustion Institute.

  10. Coastal Inlets Research Program

    Science.gov (United States)

    2014-04-01

    2003 2005 2007 2009 2011 2013 Calendar Year CIRP Website: Tech Transfer http://cirp.usace.army.mil What new technology transfer do we have to discuss...etc.), nested grids; integrated with CMS-Flow Verification & Validation Cases (14) Bouss-2D: Phase -resolving shallow- water, nonlinear wave model for...Port Orford, OR Tillamook Inlet, OR  SPN: Half Moon Bay CA Waves at  Navigation  Structures ,  SWG: Matagorda Ship Channel, TX West Galveston

  11. The influence of inlet flow condition on the frequency of self-excited jet precession

    Science.gov (United States)

    Mi, J.; Nathan, G. J.; Wong, C. Y.

    2006-01-01

    A precessing jet flow can be generated naturally by a fluidic nozzle comprising a cylindrical nozzle-chamber with a large sudden expansion at its inlet and a small lip at its outlet. Such a precessing jet flow is offset with respect to the chamber axis, about which it rotates. The aim of the present study is to investigate the influence of the chamber-inlet configuration on the frequency of such precession. Three different inlet configurations, classified as long pipe, smooth contraction, and sharp-edged orifice plate, are tested. It is found that the frequency of precession from the orifice is highest, whereas that of the pipe jet is lowest. These differences appear to result partly from the distinct differences in their respective initial boundary layers.

  12. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2007-10-15

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm{sup 2} at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode.

  13. Nozzle optimization for water jet propulsion with a positive displacement pump

    Science.gov (United States)

    Yang, You-sheng; Xie, Ying-chun; Nie, Song-lin

    2014-06-01

    In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

  14. Nozzle Optimization for Water Jet Propulsion with A Positive Displacement Pump

    Institute of Scientific and Technical Information of China (English)

    杨友胜; 谢迎春; 聂松林

    2014-01-01

    In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

  15. Transient Side Load Analysis of Out-of-Round Film-Cooled Nozzle Extensions

    Science.gov (United States)

    Wang, Ten-See; Lin, Jeff; Ruf, Joe; Guidos, Mike

    2012-01-01

    There was interest in understanding the impact of out-of-round nozzle extension on the nozzle side load during transient startup operations. The out-of-round nozzle extension could be the result of asymmetric internal stresses, deformation induced by previous tests, and asymmetric loads induced by hardware attached to the nozzle. The objective of this study was therefore to computationally investigate the effect of out-of-round nozzle extension on the nozzle side loads during an engine startup transient. The rocket engine studied encompasses a regeneratively cooled chamber and nozzle, along with a film cooled nozzle extension. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, and transient inlet boundary flow properties derived from an engine system simulation. Six three-dimensional cases were performed with the out-of-roundness achieved by three different degrees of ovalization, elongated on lateral y and z axes: one slightly out-of-round, one more out-of-round, and one significantly out-of-round. The results show that the separation line jump was the primary source of the peak side loads. Comparing to the peak side load of the perfectly round nozzle, the peak side loads increased for the slightly and more ovalized nozzle extensions, and either increased or decreased for the two significantly ovalized nozzle extensions. A theory based on the counteraction of the flow destabilizing effect of an exacerbated asymmetrical flow caused by a lower degree of ovalization, and the flow stabilizing effect of a more symmetrical flow, created also by ovalization, is presented to explain the observations obtained in this effort.

  16. Nonlinear indirect combustion noise for compact supercritical nozzle flows

    Science.gov (United States)

    Huet, M.

    2016-07-01

    In this paper, indirect combustion noise generated by the acceleration of entropy perturbations through a supercritical nozzle is investigated in the nonlinear regime and in the low-frequency limit (quasi-static hypothesis). This work completes the study of Huet and Giauque (Journal of Fluid Mechanics 733 (2013) 268-301) for nonlinear noise generation in nozzle flows without shock and particularly focuses on shocked flow regimes. It is based on the analytical model of Marble and Candel for compact nozzles (Journal of Sound and Vibration 55 (1977) 225-243), initially developed for excitations in the linear regime and rederived here for nonlinear perturbations. Full nonlinear analytical solutions are provided in the absence of shock as well as second-order analytical expressions when a shock is present in the diffuser. An analytical evaluation of the shock displacement inside the nozzle caused by the forcing is proposed and maximum possible forcings to avoid unchoke and 'over-choke' are discussed. The accuracy of the second-order model and the nonlinear contributions to the generated waves are then addressed. This model is found to be very accurate for the generated entropy wave with negligible nonlinear contributions. Nonlinearities are more visible, but still limited, for the downstream acoustic wave for large inlet Mach numbers. Analytical developments are validated thanks to comparisons with numerical simulations.

  17. Inlet Geomorphology Evolution Work Unit

    Science.gov (United States)

    2015-10-30

    the expected behavior and benefits of nearshore placement. Nearshore placement studies have been documented in two journal papers, one technical...Coastal Inlets Research Program Inlet Geomorphology Evolution Work Unit The Inlet Geomorphology Evolution work unit of the CIRP develops methods...sensing measurements, and USACE projects to create valuable guidance that address geomorphic questions. The present focus of the work unit is a common

  18. Flow in the Inlet Region in Tangential Inlet Cyclones

    NARCIS (Netherlands)

    Peng, W.; Boot, P.J.A.J.; Hoffmann, A.C; Dries, H.W.A.; Kater, J.

    2001-01-01

    In this paper the flow pattern in a tangential inlet cyclone is studied by laser Doppler anemometry, with emphasis on the inlet region. The particular focus is on axial asymmetry in the flow, which was studied by determining radial profiles of the axial and tangential gas velocity components at four

  19. Fuel injection nozzle and method of manufacturing the same

    Energy Technology Data Exchange (ETDEWEB)

    Monaghan, James Christopher; Johnson, Thomas Edward; Ostebee, Heath Michael

    2017-02-21

    A fuel injection head for use in a fuel injection nozzle comprises a monolithic body portion comprising an upstream face, an opposite downstream face, and a peripheral wall extending therebetween. A plurality of pre-mix tubes are integrally formed with and extend axially through the body portion. Each of the pre-mix tubes comprises an inlet adjacent the upstream face, an outlet adjacent the downstream face, and a channel extending between the inlet and the outlet. Each pre-mix tube also includes at least one fuel injector that at least partially extends outward from an exterior surface of the pre-mix tube, wherein the fuel injector is integrally formed with the pre-mix tube and is configured to facilitate fuel flow between the body portion and the channel.

  20. Generation 1.5 High Speed Civil Transport (HSCT) Exhaust Nozzle Program

    Science.gov (United States)

    Thayer, E. B.; Gamble, E. J.; Guthrie, A. R.; Kehret, D. F.; Barber, T. J.; Hendricks, G. J.; Nagaraja, K. S.; Minardi, J. E.

    2004-01-01

    The objective of this program was to conduct an experimental and analytical evaluation of low noise exhaust nozzles suitable for future High-Speed Civil Transport (HSCT) aircraft. The experimental portion of the program involved parametric subscale performance model tests of mixer/ejector nozzles in the takeoff mode, and high-speed tests of mixer/ejectors converted to two-dimensional convergent-divergent (2-D/C-D), plug, and single expansion ramp nozzles (SERN) in the cruise mode. Mixer/ejector results show measured static thrust coefficients at secondary flow entrainment levels of 70 percent of primary flow. Results of the high-speed performance tests showed that relatively long, straight-wall, C-D nozzles could meet supersonic cruise thrust coefficient goal of 0.982; but the plug, ramp, and shorter C-D nozzles required isentropic contours to reach the same level of performance. The computational fluid dynamic (CFD) study accurately predicted mixer/ejector pressure distributions and shock locations. Heat transfer studies showed that a combination of insulation and convective cooling was more effective than film cooling for nonafterburning, low-noise nozzles. The thrust augmentation study indicated potential benefits for use of ejector nozzles in the subsonic cruise mode if the ejector inlet contains a sonic throat plane.

  1. The effect of nozzle layout on droplet ejection of a piezo-electrically actuated micro-atomizer

    Institute of Scientific and Technical Information of China (English)

    Yanying Feng; Zhaoying Zhou; Junhua Zhu; Guibin Du

    2007-01-01

    We study here effects of nozzle layout on the droplet ejection of a micro atomizer, which was fabricated with the arrayed nozzles by the MEMS technology and actuated by a piezoelectric disc. A theoretical model was first built for this piezoelectric-liquid-structure coupling system to characterize the acoustic wave propagation in the liquid chamber, which determined the droplet formation out of nozzles. The modal analysis was carried out numerically to predict resonant frequencies and simulate the corresponding pressure wave field. By comparing the amplitude contours of pressure wave on the liquid-solid interface at nozzle inlets with the designed nozzle layout, behaviors of the device under different vibration modes can be predicted. Experimentally, an impedance analyzer was used to measure the resonant frequencies of the system. Three types of atomizers with different nozzle layouts were fabricated for measuring the effect of nozzle distribution on the ejection performance. The visualization experiment of droplet generation was carried out and volume flow rates of these devices were measured. The good agreement between the experiment and the prediction proved that only the increase of nozzles may not enhance the droplet generation and a design of nozzle distribution from a viewpoint of frequency is necessary for a resonant related atomizer.

  2. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Directory of Open Access Journals (Sweden)

    Zhang Hongsheng

    2016-06-01

    Full Text Available Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat surface and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and experimental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 °C and 78.2 °C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed; results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  3. Ground experimental investigations into an ejected spray cooling system for space closed-loop application

    Institute of Scientific and Technical Information of China (English)

    Zhang Hongsheng; Li Yunze; Wang Shengnan; Liu Yang; Zhong Mingliang

    2016-01-01

    Spray cooling has proved its superior heat transfer performance in removing high heat flux for ground applications. However, the dissipation of vapor–liquid mixture from the heat sur-face and the closed-loop circulation of the coolant are two challenges in reduced or zero gravity space environments. In this paper, an ejected spray cooling system for space closed-loop application was proposed and the negative pressure in the ejected condenser chamber was applied to sucking the two-phase mixture from the spray chamber. Its ground experimental setup was built and exper-imental investigations on the smooth circle heat surface with a diameter of 5 mm were conducted with distilled water as the coolant spraying from a nozzle of 0.51 mm orifice diameter at the inlet temperatures of 69.2 ?C and 78.2 ?C under the conditions of heat flux ranging from 69.76 W/cm2 to 311.45 W/cm2, volume flow through the spray nozzle varying from 11.22 L/h to 15.76 L/h. Work performance of the spray nozzle and heat transfer performance of the spray cooling system were analyzed;results show that this ejected spray cooling system has a good heat transfer performance and provides valid foundation for space closed-loop application in the near future.

  4. Inlet Flux Influence to Aerodynamic Performance of Steam Turbine Vane Cascade

    Directory of Open Access Journals (Sweden)

    Feng Zi-Ming

    2014-12-01

    Full Text Available In order to improve the aerodynamic performance and the performance of off-design working condition, it is necessary to research the inlet flow rate influence to overall performance of steam turbine. This study uses CFD technology to numerical simulation the flow field of nozzle cascades passage at 80, 100, 120% flow rate, respectively. The simulation results indicates that the various flow loss of nozzle have a little change at 100% design working condition, have decreased at 80% design working condition and have increased at 120% design working condition.

  5. Numerical study of steady turbulent flow through bifurcated nozzles in continuous casting

    Science.gov (United States)

    Najjar, Fady M.; Thomas, Brian G.; Hershey, Donald E.

    1995-08-01

    Bifurcated nozzles are used in continuous casting of molten steel, where they influence the quality of the cast steel slabs. The present study performs two-dimensional (2-D) and three-dimensional (3-D) simulations of steady turbulent (K- ɛ) flow in bifurcated nozzles, using a finite-element (FIDAP) model, which has been verified previously with water model experiments. The effects of nozzle design and casting process operating variables on the jet characteristics exiting the nozzle are investigated. The nozzle design parameters studied include the shape, angle, height, width, and thickness of the ports and the bottom geometry. The process operating practices include inlet velocity profile and angle as well as port curvature caused by erosion or inclusion buildup. Results show that the jet angle is controlled mainly by the port angle but is steeper with larger port area and thinner walls. The degree of swirl is increased by larger or rounder ports. The effective port area, where there is no recirculation, is increased by smaller or curved ports. Flow asymmetry is more severe with skewed or angled inlet conditions or unequal port sizes. Turbulence levels in the jet are higher with higher casting speed and smaller ports.

  6. Effects of inlet distortion on gas turbine combustion chamber exit temperature profiles

    Science.gov (United States)

    Maqsood, Omar Shahzada

    Damage to a nozzle guide vane or blade, caused by non-uniform temperature distributions at the combustion chamber exit, is deleterious to turbine performance and can lead to expensive and time consuming overhaul and repair. A test rig was designed and constructed for the Allison 250-C20B combustion chamber to investigate the effects of inlet air distortion on the combustion chamber's exit temperature fields. The rig made use of the engine's diffuser tubes, combustion case, combustion liner, and first stage nozzle guide vane shield. Rig operating conditions simulated engine cruise conditions, matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either side. An even distribution of inlet air to the combustion chamber did not create a uniform temperature profile and varying the inlet distribution of air exacerbated the profile's non-uniformity. The design of the combustion liner promoted the formation of an oval-shaped toroidal vortex inside the chamber, creating localized hot and cool sections separated by 90° that appeared in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the temperature of the hot section nearest the side with the most mass flow rate and decreasing the temperature of the hot section on the opposite side. Keywords: Allison 250, Combustion, Dual-Entry, Exit Temperature Profile, Gas Turbine, Pattern Factor, Reverse Flow.

  7. Supersonic two-phase flow of CO{sub 2} through converging-diverging nozzles for the ejector refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Masafumi [Department of Mechanical and Structural System Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi City, Aichi 441-8580 (Japan); Berana, Menandro Serrano [Department of Mechanical and Structural System Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi City, Aichi 441-8580 (Japan); Department of Mechanical Engineering, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Kishine, Akinori [Machine Tool Division, Murata Machinery, Ltd., 2 Nakajima, Hashizume, Inuyama City, Aichi 484-8502 (Japan)

    2009-09-15

    CO{sub 2} is environmentally friendly, safe and more suitable to ejector refrigeration cycle than to vapor compression cycle. Supersonic two-phase flow of CO{sub 2} in the diverging sections of rectangular converging-diverging nozzles was investigated. The divergence angles with significant variation of decompression were 0.076 , 0.153 , 0.306 and 0.612 . This paper presents experimental decompression phenomena which can be used in designing nozzles and an assessment of Isentropic Homogeneous Equilibrium (IHE). Inlet conditions around 6-9 MPa, 20-37 C were used to resemble ejector nozzles of coolers and heat pumps. For inlet temperature around 37 C, throat decompression boiling from the saturated liquid line, supersonic decompression and IHE solution were obtained for the two large divergence angles. For divergence angles larger than 0.306 , decompression curves for inlet temperature above 35 C approached IHE curves. For divergence angles smaller than 0.306 or for nozzles with inlet temperature below 35 C, IHE had no solution. (author)

  8. 33 CFR 110.170 - Lockwoods Folly Inlet, N.C.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lockwoods Folly Inlet, N.C. 110.170 Section 110.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.170 Lockwoods Folly Inlet, N.C. (a)...

  9. PAR Analysis of HSR Nozzles

    Science.gov (United States)

    Georgiadis, Nicholas J.

    1999-01-01

    Only recently has computational fluid dynamics (CFD) been relied upon to predict the flow details of advanced nozzle concepts. Computer hardware technology and flow solving techniques are advancing rapidly and CFD is now being used to analyze such complex flows. Validation studies are needed to assess the accuracy, reliability, and cost of such CFD analyses. At NASA Lewis, the PARC2D/3D full Navier-Stokes (FNS) codes are being applied to HSR-type nozzles. This report presents the results of two such PARC FNS analyses. The first is an analysis of the Pratt and Whitney 2D mixer-ejector nozzle, conducted by Dr. Yunho Choi (formerly of Sverdrup Technology-NASA Lewis Group). The second is an analysis of NASA-Langley's axisymmetric single flow plug nozzle, conducted by the author.

  10. 33 CFR 334.1310 - Lutak Inlet, Alaska; restricted areas.

    Science.gov (United States)

    2010-07-01

    ... signs will not be lighted. (2) Dry Cargo dock mooring area. (i) The waters within 60 feet off the face... dropping and dragging of anchors, weights, or other ground tackle within the Dry Cargo dock mooring area is...; restricted areas. (a) The areas—(1) Army POL dock restricted area. (i) The waters of Lutak Inlet bounded as...

  11. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    Science.gov (United States)

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  12. ADDITIONAL STRESS AND FRACTURE MECHANICS ANALYSES OF PRESSURIZED WATER REACTOR PRESSURE VESSEL NOZZLES

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Matthew [Structural Integrity Associates, Inc.; Yin, Shengjun [ORNL; Stevens, Gary [U.S. Nuclear Regulatory Commission; Sommerville, Daniel [Structural Integrity Associates, Inc.; Palm, Nathan [Westinghouse Electric Company, Cranberry Township, PA; Heinecke, Carol [Westinghouse Electric Company, Cranberry Township, PA

    2012-01-01

    In past years, the authors have undertaken various studies of nozzles in both boiling water reactors (BWRs) and pressurized water reactors (PWRs) located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Those studies described stress and fracture mechanics analyses performed to assess various RPV nozzle geometries, which were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-life (EOL) to require evaluation of embrittlement as part of the RPV analyses associated with pressure-temperature (P-T) limits. In this paper, additional stress and fracture analyses are summarized that were performed for additional PWR nozzles with the following objectives: To expand the population of PWR nozzle configurations evaluated, which was limited in the previous work to just two nozzles (one inlet and one outlet nozzle). To model and understand differences in stress results obtained for an internal pressure load case using a two-dimensional (2-D) axi-symmetric finite element model (FEM) vs. a three-dimensional (3-D) FEM for these PWR nozzles. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated. To investigate the applicability of previously recommended linear elastic fracture mechanics (LEFM) hand solutions for calculating the Mode I stress intensity factor for a postulated nozzle corner crack for pressure loading for these PWR nozzles. These analyses were performed to further expand earlier work completed to support potential revision and refinement of Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50, Appendix G, Fracture Toughness Requirements, and are intended to supplement similar evaluation of nozzles presented at the 2008, 2009, and 2011 Pressure Vessels and Piping (PVP

  13. Effects of Nozzle Scale, Total Temperature and an Afterburner on Jet Noise from a Pre-Cooled Turbojet Engine

    Science.gov (United States)

    Araki, Mikiya; Sano, Takayuki; Fukuda, Masayuki; Kojima, Takayuki; Taguchi, Hideyuki; Nishida, Shunsuke; Imamura, Osamu; Shiga, Seiichi; Tsue, Mitsuhiro

    Effects of nozzle scale, total temperature, and an afterburner on jet noise characteristics from a pre-cooled turbojet engine are investigated experimentally. In JAXA (Japan Aerospace Exploration Agency), a pre-cooled turbojet engine for an HST (Hypersonic transport) is under development. In the present study, 1.0%- and 2.4%-scaled models of the rectangular plug nozzle (Nozzles I and II) are manufactured, and the jet noise characteristics are investigated under a wide range of total temperatures. For Nozzle I, no air-heater is utilized and the total temperature is 290K. For Nozzle II, a pebble heater and an afterburner (AB) are utilized upstream of the nozzle model, and the total temperature is varied from 520K (pebble heater) to 1540K (pebble heater + AB). The total pressure is set at 0.27 and 0.30MPa(a) for both nozzle models. Jet noise is measured using a high-frequency microphone set at 135 deg from the engine inlet, and normalized jet noise spectra are obtained based on AUjn law and Helmholtz number. For cases without afterburner, the normalized spectra agrees well regardless of the nozzle scale and total temperature where the velocity index lies from n = 7.7 to 9.2, and the correlation factor between the two facilities is shown to be about 1dB. For the case with afterburner, the normalized spectrum does not agree with other conditions where the velocity index n seems to be about 4.

  14. Simulation of the fluidic features for diffuser/nozzle involved in a PZT-based valveless micropump

    Institute of Scientific and Technical Information of China (English)

    HouWensheng; Zheng Xiaolin; Biswajit Das; Jiang Yingtao; Qian Shizhi; Wu Xiaoying; Zheng Zhigao

    2008-01-01

    PZT-based valveless micropump is a microactuator that can be used for controlling and delivering tiny amounts of fluids, and diffuser/nozzle plays an important role when this type of micropump drives the fluid flowing along a specific direction. In this paper, a numerical model of micropump has been proposed, and the fluidic properties of diffuser/nozzle have been simulated with ANSYS. With the method of finite-element analysis, the increased pressure drop between inlet and outlet of diffuser/nozzle induces the increment of flow rate in both diffuser and nozzle simultaneously, but the increasing rate of diffuser is faster than that of nozzle. The L/R, ratio of L (length of cone pipe) and R (radius of minimal cross section of cone pipe) plays an important role in fluidic performance of diffuser and nozzle as well, and the mean flow rate will decrease with increment of L/R. The mean flow rate reaches its peak value when L/R with the value of 10 regardless the divergence angle of diffuser or nozzle. The simulation results indicate that the fluidic properties of diffuser/nozzle can be defined by its geometric structure, and accordingly determine the efficiency of micropump.

  15. Control of Inflow Distortion in a Scarf Inlet

    Science.gov (United States)

    Gerhold, Carl H.; Clark, Lorenzo R.; Biedron, Robert T.

    2002-01-01

    The scarf inlet has the potential to reduce aircraft inlet noise radiation to the ground by reflecting it into the space above the engine. Without forward motion of the engine, the non-symmetry of the inlet causes inflow distortion which generates noise that is greater than the noise reduction of the scarf. However, acoustic evaluations of aircraft engines are often done on static test stands. A method to reduce inflow distortion by boundary layer suction is proposed and evaluated using a model of a high bypass ratio engine located in an anechoic chamber. The design goal of the flow control system is to make the inflow to the inlet circumferentially uniform and to eliminate reversed flow. This minimizes the inflow distortion and allows for acoustic evaluation of the scarf inlet on a static test stand. The inlet boundary layer suction effectiveness is evaluated both by aerodynamic and by acoustic measurements. Although the design goal is not met, the control system is found to have a beneficial effect on the engine operation, reducing blade stall and speed variation. This is quantified by two acoustic benefits, reduction both of the variability of tone noise and of the low frequency wideband noise due to the inflow distortion. It is felt that a compromise in the manufacture of the control hardware contributes to the inability of the control system to perform as expected from the analysis. The control system with sufficient authority is felt to have the potential to permit reliable acoustic testing in a static configuration of engines with non-symmetric inlets. Because the control system can improve operation of the engine, it may also have the potential to reduce noise and vibration and enhance engine longevity during low speed ground operations in the terminal area.

  16. Preliminary Two-Phase Terry Turbine Nozzle Models for RCIC Off-Design Operation Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-06-12

    This report presents the effort to extend the single-phase analytical Terry turbine model to cover two-phase off-design conditions. The work includes: (1) adding well-established two-phase choking models – the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model, and (2) theoretical development and implementation of a two-phase nozzle expansion model. The two choking models provide bounding cases for the two-phase choking mass flow rate. The new two-phase Terry turbine model uses the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. In the divergent stage, we only consider the vapor phase with a similar model for the single-phase case by assuming that the liquid phase would slip along the wall with a much slower speed and will not contribute the impulse on the rotor. We also modify the stagnation conditions according to two-phase choking conditions at the throat and the cross-section areas for steam flow at the nozzle throat and at the nozzle exit. The new two-phase Terry turbine model was benchmarked with the same steam nozzle test as for the single-phase model. Better agreement with the experimental data is observed than from the single-phase model. We also repeated the Terry turbine nozzle benchmark work against the Sandia CFD simulation results with the two-phase model for the pure steam inlet nozzle case. The RCIC start-up tests were simulated and compared with the single-phase model. Similar results are obtained. Finally, we designed a new RCIC system test case to simulate the self-regulated Terry turbine behavior observed in Fukushima accidents. In this test, a period inlet condition for the steam quality varying from 1 to 0 is applied. For the high quality inlet period, the RCIC system behaves just like the normal operation condition with a high pump injection flow rate and a nominal steam release rate through the turbine, with the net addition of water to the primary system; for

  17. Ground control point locations associated with images collected during unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (Text file and photos)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset documents the locations of ground control points associated with images obtained from unmanned aerial systems (UAS) flown in the Cape Cod National...

  18. Ground control point locations associated with images collected during unmanned aerial systems (UAS) flights over Coast Guard Beach, Nauset Spit, Nauset Inlet, and Nauset Marsh, Cape Cod National Seashore, Eastham, Massachusetts on 1 March 2016 (Text file and photos)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset documents the locations of ground control points associated with images obtained from unmanned aerial systems (UAS) flown in the Cape Cod National...

  19. Nozzle geometry for organic vapor jet printing

    Science.gov (United States)

    Forrest, Stephen R; McGraw, Gregory

    2015-01-13

    A first device is provided. The device includes a print head. The print head further includes a first nozzle hermetically sealed to a first source of gas. The first nozzle has an aperture having a smallest dimension of 0.5 to 500 microns in a direction perpendicular to a flow direction of the first nozzle. At a distance from the aperture into the first nozzle that is 5 times the smallest dimension of the aperture of the first nozzle, the smallest dimension perpendicular to the flow direction is at least twice the smallest dimension of the aperture of the first nozzle.

  20. Inlet effect on the coal pyrolysis to acetylene in a hydrogen plasma downer reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Y.; Chen, J.Q.; Ding, Y.L.; Jin, Y. [Tsinghua Univ., Beijing (China). Dept. of Chemical Engineering, Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology; Xiong, X.Y. [Xinjiang Tianye Corp., Shihezi (China)

    2008-06-15

    In this study a gas-solid downer reactor was used to characterize high temperature reactions of coal pyrolysis. The aim of the study was to examine the influence of the coal injection design on reactor performance in a 2 MW plasma reactor. Computational fluid dynamics (CFD) simulations were used to model complex reacting flows in the coal pyrolysis process in order to examine the effects of nozzle design on the initial distribution of the coal particles. A 2-fluid model was used to calculate solids viscosity and pressure from the kinetic theory of granular flow as well as to solve partial differential equations for granular temperatures. Results of the simulations showed that gas flow and particle jets through the nozzles played a significant role in the distribution of the coal particles. Coal dispersion at the inlet was dependent on flow conditions. Flat-shaped nozzles provided flexible control on gas-particle contacts during the initial stages. When the layout of the nozzles was tuned, solids flow formed either swirling or non-swirling actions in the reactor. It was concluded that the volume fraction of the acetylene in the product gas was increased by more than 20 per cent when the nozzles were optimally arranged. 9 refs., 1 tab., 8 figs.

  1. A Turbine Based Combined Cycle Engine Inlet Model and Mode Transition Simulation Based on HiTECC Tool

    Science.gov (United States)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2012-01-01

    An inlet system is being tested to evaluate methodologies for a turbine based combined cycle propulsion system to perform a controlled inlet mode transition. Prior to wind tunnel based hardware testing of controlled mode transitions, simulation models are used to test, debug, and validate potential control algorithms. One candidate simulation package for this purpose is the High Mach Transient Engine Cycle Code (HiTECC). The HiTECC simulation package models the inlet system, propulsion systems, thermal energy, geometry, nozzle, and fuel systems. This paper discusses the modification and redesign of the simulation package and control system to represent the NASA large-scale inlet model for Combined Cycle Engine mode transition studies, mounted in NASA Glenn s 10- by 10-Foot Supersonic Wind Tunnel. This model will be used for designing and testing candidate control algorithms before implementation.

  2. Turbomachine combustor nozzle including a monolithic nozzle component and method of forming the same

    Energy Technology Data Exchange (ETDEWEB)

    Stoia, Lucas John; Melton, Patrick Benedict; Johnson, Thomas Edward; Stevenson, Christian Xavier; Vanselow, John Drake; Westmoreland, James Harold

    2016-02-23

    A turbomachine combustor nozzle includes a monolithic nozzle component having a plate element and a plurality of nozzle elements. Each of the plurality of nozzle elements includes a first end extending from the plate element to a second end. The plate element and plurality of nozzle elements are formed as a unitary component. A plate member is joined with the nozzle component. The plate member includes an outer edge that defines first and second surfaces and a plurality of openings extending between the first and second surfaces. The plurality of openings are configured and disposed to register with and receive the second end of corresponding ones of the plurality of nozzle elements.

  3. Kinetic energy of rainfall simulation nozzles

    Science.gov (United States)

    Different spray nozzles are used frequently to simulate natural rain for soil erosion and chemical transport, particularly phosphorous (P), studies. Oscillating VeeJet nozzles are used mostly in soil erosion research while constant spray FullJet nozzles are commonly used for P transport. Several ch...

  4. Rarefaction Waves at the Outlet of the Supersonic Two-Phase Flow Nozzle

    Science.gov (United States)

    Nakagawa, Masafumi; Miyazaki, Hiroki; Harada, Atsushi

    Two-phase flow nozzles are used in the total flow system for geothermal power plants and in the ejector of the refrigerant cycle, etc. One of the most important functions of a two-phase flow nozzle is to convert the thermal energy to the kinetic energy of the two-phase flow. The kinetic energy of the two-phase flow exhausted from a nozzle is available for all applications of this type. There exist the shock waves or rarefaction waves at the outlet of a supersonic nozzle in the case of non-best fitting expansion conditions when the operation conditions of the nozzle are widely chosen. Those waves affect largely on the energy conversion efficiency of the two-phase flow nozzle. The purpose of the present study is to elucidate the character of the rarefaction waves at the outlet of the supersonic two-phase flow nozzle. The high pressure hot water blow down experiment has been carried out. The decompression curves by the rarefaction waves are measured by changing the flow rate of the nozzle and inlet temperature of the hot water. The back pressures of the nozzle are also changed in those experiments. The divergent angles of the two-phase flow flushed out from the nozzle are measured by means of the photograph. The experimental results show that the recompression curves are different from those predicted by the isentropic homogenous two-phase flow. The regions where the rarefaction waves occur become wide due to the increased outlet speed of two-phase flow. The qualitative dependency of this expansion character is the same as the isotropic homogenous flow, but the values obtained from the experiments are quite different. When the back pressure of the nozzle is higher, these regions do not become small in spite of the super sonic two-phase flow. This means that the disturbance of the down-stream propagate to the up-stream. It is shown by the present experiments that the rarefaction waves in the supersonic two-phase flow of water have a subsonic feature. The measured

  5. Expansion Waves at the Outlet of the Supersonic Two-Phase Flow Nozzle

    Science.gov (United States)

    Nakagawa, Masafumi; Miyazaki, Hiroki; Harada, Atsushi; Ibragimov, Zokirjon

    Two-phase flow nozzles are used in the total flow system of geothermal power plants and in the ejector of the refrigeration cycle, etc. One of the most important functions of the two-phase flow nozzle is converting two-phase flow thermal energy into kinetic energy. The kinetic energy of the two-phase flow exhausted from a nozzle is available for all applications of this type. In the case of non-best fitting expansion conditions, when the operation conditions of the supersonic nozzle are widely chosen, there exist shock waves or expansion waves at the outlet of the nozzle. Those waves affect largely the energy conversion efficiency of the two-phase flow nozzle. The purpose of the present study is to elucidate character of the expansion waves at the outlet of the supersonic two-phase flow nozzle. High-pressure hot water blowdown experiments have been carried out. The decompression curves of the expansion waves are measured by changing the flowrate in the nozzle and inlet temperature of the hot water. The back pressures of the nozzle are also changed in those experiments. The expansion angles of the two-phase flow flushed out from the nozzle are measured by means of the photograph. The experimental results show that the decompression curves are different from those predicted by the isentropic homogeneous two-phase flow theory. The regions where the expansion waves occur become wide due to the increased outlet speed of the two-phase flow. The qualitative dependency of this expansion character is the same as the isentropic homogeneous flow, but the values obtained from the experiments are quite different. When the back pressure of the nozzle is higher, these regions do not become small in spite of the supersonic two-phase flow. This means that the disturbance in the downstream propagates to the upstream. It is shown by the present experiments that the expansion waves in the supersonic two-phase flow of water have a subsonic feature. The measured expansion angles become

  6. Method for Determining Optimum Injector Inlet Geometry

    Science.gov (United States)

    Trinh, Huu P. (Inventor); Myers, W. Neill (Inventor)

    2015-01-01

    A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The method calculates the tangential inlet area for each throttleable stage. The method also uses correlation between the tangential inlet areas and delta pressure values to calculate the spring displacement and variable inlet geometry of a liquid rocket engine swirl injector.

  7. Centrifugal pump inlet pressure site affects measurement.

    Science.gov (United States)

    Augustin, Simon; Horton, Alison; Butt, Warwick; Bennett, Martin; Horton, Stephen

    2010-09-01

    During extracorporeal life support (ECLS), blood is exposed to a myriad of unphysiological factors that can affect outcome. One aspect of this is the sub-atmospheric pressure generated by the ECLS pump and imparted to blood elements along the pump inlet line. This pressure can be measured on the inlet line close to the pump head by adding a connector, or at the venous cannula connection site. We compared the two measurement sites located at both points; between the venous cannula-inlet tubing and inlet tubing-pump, with a range of cannulae and flows. We also investigated the effects on inlet pressure from pump afterload and increasing inlet tubing length.

  8. Nozzle Bricks and Well Bricks

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2011-01-01

    1 Scope This standard specifies the classification,brand,technical requirements,test methods,inspection rules,marking,packing,transportation,storage,and quality certificate of nozzle bricks and well bricks.This standard is applicable to unfired and fired products.

  9. Nozzle for electric dispersion reactor

    Science.gov (United States)

    Sisson, Warren G.; Basaran, Osman A.; Harris, Michael T.

    1995-01-01

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  10. Apparatus for mixing fuel in a gas turbine nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Carl Robert

    2016-11-22

    A fuel nozzle in a combustion turbine engine that includes: a fuel plenum defined between an circumferentially extending shroud and axially by a forward tube-sheet and an aft tube-sheet; and a mixing-tube that extends across the fuel plenum that defines a passageway connecting an inlet formed through the forward tube-sheet and an outlet formed through the aft tube-sheet, the mixing-tube comprising one or more fuel ports that fluidly communicate with the fuel plenum. The mixing-tube may include grooves on an outer surface, and be attached to the forward tube-sheet by a connection having a fail-safe leakage path.

  11. Investigation of Pneumatic Inlet and Diffuser Blowing on a Ducted Fan Propulsor in Static Thrust Operation

    Science.gov (United States)

    Kondor, Shayne; Englar, Robert J.; Lee, Warren J.

    2003-01-01

    Tilting ducted fans present a solution for the lifting and forward flight propulsion requirements of VTOL aircraft. However, the geometry of the duct enshrouding the propeller has great a effect on the efficiency of the fan in various flight modes. Shroud geometry controls the velocity and pressure at the face of the fan, while maintaining a finite loading out at the tips of the fan blades. A duct tailored for most efficient generation of static lifting thrust will generally suffer from performance deficiencies in forward flight. The converse is true as well, leaving the designer with a difficult trade affecting the overall performance and sizing of the aircraft. Ideally, the shroud of a vertical lifting fan features a generous bell mouth inlet promoting acceleration of flow into the face of the fan, and terminating in a converging nozzle at the exit. Flow entering the inlet is accelerated into the fan by the circulation about the shroud, resulting in an overall increase in thrust compared to an open propeller operating under the same conditions . The accelerating shroud design is often employed in lifting ducted fans to benefit from the thrust augmentation; however, such shroud designs produce significant drag penalties in axial flight, thus are unsuitable for efficient forward flight applications. Decelerating, or diffusing, duct designs are employed for higher speed forward flight configurations. The lower circulation on the shroud tends to decelerate the flow into the face of the fan, which is detrimental to static thrust development; however, net thrust is developed on the shroud while the benefits of finite blade loading are retained. With judicious shroud design for intended flight speeds, a net increase in efficiency can be obtained over an open propeller. In this experiment, conducted under contract to NASA LaRC (contract NAG-1-02093) circulation control is being applied to a mildly diffusing shroud design, intended for improved forward flight performance

  12. Effect of front guide nozzle shape on the flow characteristics in an augmentation channel of a direct drive turbine for wave power generation

    Institute of Scientific and Technical Information of China (English)

    Deepak; PRASAD; Mohammed; Asid; ZULLAH; Mohammed; Rafiuddin; AHMED; Young-Ho; LEE

    2010-01-01

    There is an increasing interest in cross flow turbines(also known as Banki turbines) for small and low head applications because of their simple structure as well as low capital and maintenance costs.The present work aims at implementing the direct drive turbine(DDT) of cross flow type for wave power generation.A numerical wave tank was used to simulate the waves and after obtaining the desired wave properties;the augmentation channel plus the front guide nozzle and rear chamber were integrated to the numerical wave tank.The waves in the numerical wave tank were generated by a piston type wave maker which was located at the wave tank inlet.The inlet which was modeled as a plate wall moved sinusoidally with the general function x = asinω t.The augmentation channel consisted of a front nozzle,rear nozzle and an internal fluid region which represented the turbine housing.The front and rear nozzles were geometrically the same.Three different front guide nozzle configurations were studied:a standard guide nozzle which was originally attached to the augmentation channel and two other front guide nozzles of different geometries.The purpose of this study is to observe how the front guide nozzle shape influences the flow downstream,mainly in the augmenta-tion channel,water power and the first stage energy conversion.The analysis was performed using a commercial CFD code ANSYS-CFX.The results of the flow in the augmentation channel for the three front guide nozzles are presented in this paper.

  13. Frozen Chemistry Effects on Nozzle Performance Simulations

    Science.gov (United States)

    Yoder, Dennis A.; Georgiadis, Nicholas J.; O'Gara, Michael R.

    2009-01-01

    Simulations of exhaust nozzle flows are typically conducted assuming the gas is calorically perfect, and typically modeled as air. However the gas inside a real nozzle is generally composed of combustion products whose thermodynamic properties may differ. In this study, the effect of gas model assumption on exhaust nozzle simulations is examined. The three methods considered model the nozzle exhaust gas as calorically perfect air, a calorically perfect exhaust gas mixture, and a frozen exhaust gas mixture. In the latter case the individual non-reacting species are tracked and modeled as a gas which is only thermally perfect. Performance parameters such as mass flow rate, gross thrust, and thrust coefficient are compared as are mean flow and turbulence profiles in the jet plume region. Nozzles which operate at low temperatures or have low subsonic exit Mach numbers experience relatively minor temperature variations inside the nozzle, and may be modeled as a calorically perfect gas. In those which operate at the opposite extreme conditions, variations in the thermodynamic properties can lead to different expansion behavior within the nozzle. Modeling these cases as a perfect exhaust gas flow rather than air captures much of the flow features of the frozen chemistry simulations. Use of the exhaust gas reduces the nozzle mass flow rate, but has little effect on the gross thrust. When reporting nozzle thrust coefficient results, however, it is important to use the appropriate gas model assumptions to compute the ideal exit velocity. Otherwise the values obtained may be an overly optimistic estimate of nozzle performance.

  14. Tidal Motion in a Complex Inlet and Bay System, Ponce de Leon Inlet, Florida

    Science.gov (United States)

    2000-01-01

    REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Tidal Motion in a Complex Inlet and Bay System, Ponce de Leon Inlet, Florida 5a...investigated in Ponce de Leon (Ponce) Inlet, Florida, and its bay channels through a 10-week data-collection campaign and two-dimensional numerical...Beach, Florida Summer 2000 Tidal Motion in a Complex Inlet and Bay System, Ponce de Leon Inlet, Florida Adele Militellot and Gary A. Zarillo:j: t

  15. Thrust Enhancement in Hypervelocity Nozzles by Chemical Catalysis

    Science.gov (United States)

    Singh, D. J.; Carpenter, Mark H.; Drummond, J. P.

    1997-01-01

    In the hypersonic flight regime, the air-breathing supersonic combustion ramjet (scramjet) has been shown to be a viable propulsion system. The current designs of scramjet engines provide performance benefits only up to a Mach number of 14. Performance losses increase rapidly as the Mach number increases. To extend the applicability of scram'jets beyond Mach 14, research is being conducted in the area of inlet and wave drag reduction, skin-friction and heat-transfer reduction, nozzle loss minimization, low-loss mixing, and combustion enhancement. For high Mach number applications, hydrogen is the obvious fuel choice because of its high energy content per unit mass in comparison with conventional fuels. These flight conditions require engines to operate at supersonic internal velocities, high combustor temperatures, and low static pressures. The high static temperature condition enhances the production of radicals such as H and OH, and the low-pressure condition slows the reaction rates, particularly the recombination reactions. High-temperature and low-pressure constraints, in combination with a small residence time, result in a radical-rich exhaust gas mixture exiting the combustor. At high Mach number conditions (due to low residence time), H and OH do not have enough time to recombine ; thus, a significant amount of energy is lost as these high-energy free radical are exhausted. The objective of the present study is to conduct a flowfield analysis for a typical nozzle geometry for NASP-type vehicle to assess for thrust enhancement in hypervelocity nozzles by substituting small amount of phosphine for hydrogen.

  16. A numerical study of cavitating flows in high-pressure diesel injection nozzle holes using a two-fluid model

    Institute of Scientific and Technical Information of China (English)

    WANG Xiang; SU WanHua

    2009-01-01

    Cavitating flows inside a diesel injection nozzle hole were simulated using a two-fluid model. Attention was focused on the complex cavitation processes and flow characteristics under constant inlet pres-sure and fluctuant inlet pressure modes. To validate the two-fluid model, model predictions were compared with the experimental data available in the literatures, and good agreement was achieved. The numerical results show that the appearance of supercavitation in the diesel nozzle hole induces obvious changes of flow field structures and exit flow conditions, The distributions of liquid phase turbulent kinetic energy and exit velocity profiles corresponding to the supercavitation regime indicate the potential for promoting the primary breakup of a diesel jet. Furthermore, the upstream pressure fluctuations significantly influence the cavitation processes. Both partial cavitation and supercavitation show unsteady behaviors as the rapid rise or fall of upstream pressure.

  17. EXAMPLE OF FLOW MODELLING CHARACTERISTICS IN DIESEL ENGINE NOZZLE

    Directory of Open Access Journals (Sweden)

    Dušan KOLARIČ

    2016-03-01

    research presents the influence of various volume mesh types on flow characteristics inside a fuel injector nozzle. Our work is based upon the creating of two meshes in the CFD software package. Each of them was used two times. First, a time-dependent mass flow rate was defined at the inlet region and pressure was defined at the outlet. The same mesh was later used to perform a simulation with a defined needle lift curve (and hereby the mesh movement and inlet and outlet pressure. In next few steps we investigated which approach offered better results and would thus be most suitable for engineering usage.

  18. Variable volume combustor with pre-nozzle fuel injection system

    Energy Technology Data Exchange (ETDEWEB)

    Keener, Christopher Paul; Johnson, Thomas Edward; McConnaughhay, Johnie Franklin; Ostebee, Heath Michael

    2016-09-06

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of fuel nozzles, a pre-nozzle fuel injection system supporting the fuel nozzles, and a linear actuator to maneuver the fuel nozzles and the pre-nozzle fuel injection system.

  19. Environmental continuous air monitor inlet with combined preseparator and virtual impactor

    Science.gov (United States)

    Rodgers, John C.

    2007-06-19

    An inlet for an environmental air monitor is described wherein a pre-separator interfaces with ambient environment air and removes debris and insects commonly associated with high wind outdoors and a deflector plate in communication with incoming air from the pre-separator stage, that directs the air radially and downward uniformly into a plurality of accelerator jets located in a manifold of a virtual impactor, the manifold being cylindrical and having a top, a base, and a wall, with the plurality of accelerator jets being located in the top of the manifold and receiving the directed air and accelerating directed air, thereby creating jets of air penetrating into the manifold, where a major flow is deflected to the walls of the manifold and extracted through ports in the walls. A plurality of receiver nozzles are located in the base of the manifold coaxial with the accelerator jets, and a plurality of matching flow restrictor elements are located in the plurality of receiver nozzles for balancing and equalizing the total minor flow among all the plurality of receiver nozzles, through which a lower, fractional flow extracts large particle constituents of the air for collection on a sample filter after passing through the plurality of receiver nozzles and the plurality of matching flow restrictor elements.

  20. Simulation of a Downsized FDM Nozzle

    DEFF Research Database (Denmark)

    Hofstätter, Thomas; Pimentel, Rodrigo; Pedersen, David B.

    2015-01-01

    This document discusses the simulat-ion of a downsized nozzle for fused deposition modelling (FDM), namely the E3D HotEnd Extruder with manufactured diameters of 200-400 μm in the nozzle tip. The nozzle has been simulated in terms of heat transfer and fluid flow giving an insight into the physical...... validated. This kind of simulations is facing multiple problems connected to the description of the material properties with temperature and pressure dependency....

  1. MHD Simulations of the Plasma Flow in the Magnetic Nozzle

    Science.gov (United States)

    Smith, T. E. R.; Keidar, M.; Sankaran, K.; olzin, K. A.

    2013-01-01

    The magnetohydrodynamic (MHD) flow of plasma through a magnetic nozzle is simulated by solving the governing equations for the plasma flow in the presence of an static magnetic field representing the applied nozzle. This work will numerically investigate the flow and behavior of the plasma as the inlet plasma conditions and magnetic nozzle field strength are varied. The MHD simulations are useful for addressing issues such as plasma detachment and to can be used to gain insight into the physical processes present in plasma flows found in thrusters that use magnetic nozzles. In the model, the MHD equations for a plasma, with separate temperatures calculated for the electrons and ions, are integrated over a finite cell volume with flux through each face computed for each of the conserved variables (mass, momentum, magnetic flux, energy) [1]. Stokes theorem is used to convert the area integrals over the faces of each cell into line integrals around the boundaries of each face. The state of the plasma is described using models of the ionization level, ratio of specific heats, thermal conductivity, and plasma resistivity. Anisotropies in current conduction due to Hall effect are included, and the system is closed using a real-gas equation of state to describe the relationship between the plasma density, temperature, and pressure.A separate magnetostatic solver is used to calculate the applied magnetic field, which is assumed constant for these calculations. The total magnetic field is obtained through superposition of the solution for the applied magnetic field and the self-consistently computed induced magnetic fields that arise as the flowing plasma reacts to the presence of the applied field. A solution for the applied magnetic field is represented in Fig. 1 (from Ref. [2]), exhibiting the classic converging-diverging field pattern. Previous research was able to demonstrate effects such as back-emf at a super-Alfvenic flow, which significantly alters the shape of the

  2. Apparatus and method for grounding compressed fuel fueling operator

    Science.gov (United States)

    Cohen, Joseph Perry; Farese, David John; Xu, Jianguo

    2002-06-11

    A safety system for grounding an operator at a fueling station prior to removing a fuel fill nozzle from a fuel tank upon completion of a fuel filling operation is provided which includes a fuel tank port in communication with the fuel tank for receiving and retaining the nozzle during the fuel filling operation and a grounding device adjacent to the fuel tank port which includes a grounding switch having a contact member that receives physical contact by the operator and where physical contact of the contact member activates the grounding switch. A releasable interlock is included that provides a lock position wherein the nozzle is locked into the port upon insertion of the nozzle into the port and a release position wherein the nozzle is releasable from the port upon completion of the fuel filling operation and after physical contact of the contact member is accomplished.

  3. Effects of nonuniform Mach-number entrance on scramjet nozzle flowfield and performance

    Science.gov (United States)

    Zhang, Pu; Xu, Jinglei; Quan, Zhibin; Mo, Jianwei

    2016-12-01

    Considering the non-uniformities of nozzle entrance influenced by the upstream, the effects of nonuniform Mach-number coupled with shock and expansion-wave on the flowfield and performances of single expansion ramp nozzle (SERN) are numerically studied using Reynolds-Averaged Navier-Stokes equations. The adopted Reynolds-averaged Navier-Stokes methodology is validated by comparing the numerical results with the cold experimental data, and the average method used in this paper is discussed. Uniform and nonuniform facility nozzles are designed to generate different Mach-number profile for the inlet of SERN, which is direct-connected with different facility nozzle, and the whole flowfield is simulated. Because of the coupling of shock and expansion-wave, flow direction of nonuniform SERN entrance is distorted. Compared with Mach contour of uniform case, the line is more curved for coupling shock-wave entrance (SWE) case, and flatter for the coupling expansion-wave entrance (EWE) case. Wall pressure distribution of SWE case appears rising region, whereas decreases like stairs of EWE case. The numerical results reveal that the coupled shock and expansion-wave play significant roles on nozzle performances. Compared with the SERN performances of uniform entrance case at the same work conditions, the thrust of nonuniform entrance cases reduces by 3-6%, pitch moment decreases by 2.5-7%. The negative lift presents an incremental trend with EWE while the situation is the opposite with SWE. These results confirm that considering the entrance flow parameter nonuniformities of a scramjet nozzle coupled with shock or expansion-wave from the upstream is necessary.

  4. Numerical analysis of choked converging nozzle flows with surface roughness and heat flux conditions

    Indian Academy of Sciences (India)

    A Alper Ozalp

    2006-02-01

    Choked converging nozzle flow and heat transfer characteristics are numerically investigated by means of a recent computational model that integrates the axisymmetric continuity, state, momentum and energy equations. To predict the combined effects of nozzle geometry, friction and heat transfer rates, analyses are conducted with sufficiently wide ranges of covergence half angle, surface roughness and heat flux conditions. Numerical findings show that inlet Mach and Nusselt numbers decrease up to 23.1% and 15.8% with surface heat flux and by 15.13% and 4.8% due to surface roughness. Considering each convergence half angle case individually results in a linear relation between nozzle discharge coefficients and exit Reynolds numbers with similar slopes. Heat flux implementation, by decreasing the shear stress values, lowers the risks due to wear hazards at upstream sections of flow walls; however the final 10% downstream nozzle portion is determined to be quite critical, where shear stress attains the highest magnitudes. Heat transfer rates are seen to increase in the streamwise direction up to 2.7 times; however high convergence half angles, heat flux and surface roughness conditions lower inlet Nusselt numbers by 70%, 15.8% and 4.8% respectively.

  5. Through an Annular Turbine Nozzle

    Directory of Open Access Journals (Sweden)

    Rainer Kurz

    1995-01-01

    is located in the gas turbine. The experiments were performed using total pressure probes and wall static pressure taps. The pitch variation modifies the flow field both upstream and downstream of the nozzle, although the experiments show that the effect is localized to the immediate neighborhood of the involved blades. The effects on the wakes and on the inviscid flow are discussed separately. The mean velocities show a strong sensitivity to the changes of the pitch, which is due to a potential flow effect rather than a viscous effect.

  6. Vacuum pressure generation via microfabricated converging-diverging nozzles for operation of automated pneumatic logic.

    Science.gov (United States)

    Christoforidis, Theodore; Werner, Erik M; Hui, Elliot E; Eddington, David T

    2016-08-01

    Microfluidic devices with integrated pneumatic logic enable automated fluid handling without requiring external control instruments. These chips offer the additional advantage that they may be powered by vacuum and do not require an electricity source. This work describes a microfluidic converging-diverging (CD) nozzle optimized to generate vacuum at low input pressures, making it suitable for microfluidic applications including powering integrated pneumatic logic. It was found that efficient vacuum pressure was generated for high aspect ratios of the CD nozzle constriction (or throat) width to height and diverging angle of 3.6(o). In specific, for an inlet pressure of 42.2 psia (290.8 kPa) and a volumetric flow rate of approximately 1700 sccm, a vacuum pressure of 8.03 psia (55.3 kPa) was generated. To demonstrate the capabilities of our converging - diverging nozzle device, we connected it to a vacuum powered peristaltic pump driven by integrated pneumatic logic and obtained tunable flow rates from 0 to 130 μL/min. Finally, we demonstrate a proof of concept system for use where electricity and vacuum pressure are not readily available by powering a CD nozzle with a bicycle tire pump and pressure regulator. This system is able to produce a stable vacuum sufficient to drive pneumatic logic, and could be applied to power automated microfluidics in limited resource settings.

  7. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction.

    Science.gov (United States)

    Fritz, Bradley K; Hoffmann, W Clint

    2016-09-16

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.

  8. Planar Inlet Design and Analysis Process (PINDAP)

    Science.gov (United States)

    Slater, John W.; Gruber, Christopher R.

    2005-01-01

    The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

  9. Laval nozzles for cluster-jet targets

    Energy Technology Data Exchange (ETDEWEB)

    Hergemoeller, Ann-Katrin; Bonaventura, Daniel; Grieser, Silke; Koehler, Esperanza; Taeschner, Alexander; Khoukaz, Alfons [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet Muenster, 48149 Muenster (Germany)

    2014-07-01

    Cluster-jet targets are highly suited as internal targets for storage ring experiments. Here the target beam itself is produced by the expansion of pre-cooled gases within fine Laval nozzles. With such targets high and constant target beam thicknesses can be achieved and adjusted continuously during operation. At the prototype cluster-jet target for the PANDA experiment, which was built up and set successfully into operation at the University of Muenster, density structures within the cluster beam directly behind the nozzle have been observed. Therefore, a tilting system was installed, allowing for an adjustment of the nozzle system relative to the experimental setup. With this installation target densities of more than 2 x 10{sup 15} atoms/cm{sup 2} at a distance of 2.1 m behind the nozzle were achieved. To study the impact of the Laval nozzle geometry on the beam structures and the achievable density, an improved nozzle production method was established. With this technique it is possible to produce with high efficiency fine micrometer-sized nozzles with variable geometries, e.g. different opening angles, opening diameters or lengths of the exit trumpet. The method for the production of Laval nozzles are presented, and new perspectives are discussed.

  10. Study of Nozzle and Vent Locations on Die Casting Filling Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The casting nozzle location plays an important role in die casting. Improper location results in defects, such as cold shut, air cavity, shrinkage, etc. Therefore, it's sure that the molten metal full fills the mould cavity before it solidifies. And, it's to be wished that no vortex occur during the filling process, because the vortex is a main source that induces gas entrapment. To get the high quality and performance product, the inlet and outlet locations must be set properly. This paper, an optimal desi...

  11. Flow and Noise from Septa Nozzles

    Science.gov (United States)

    Zaman, K. B. M. Q.; Bridges, J. E.

    2017-01-01

    Flow and noise fields are explored for the concept of distributed propulsion. A model-scale experiment is performed with an 8:1 aspect ratio rectangular nozzle that is divided into six passages by five septa. The septa geometries are created by placing plastic inserts within the nozzle. It is found that the noise radiation from the septa nozzle can be significantly lower than that from the baseline rectangular nozzle. The reduction of noise is inferred to be due to the introduction of streamwise vortices in the flow. The streamwise vortices are produced by secondary flow within each passage. Thus, the geometry of the internal passages of the septa nozzle can have a large influence. The flow evolution is profoundly affected by slight changes in the geometry. These conclusions are reached by mostly experimental results of the flowfield aided by brief numerical simulations.

  12. Aerosol Inlet Characterization Experiment Report

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, Robert L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kuang, Chongai [Brookhaven National Lab. (BNL), Upton, NY (United States); Uin, Janek [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-05-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerosol Observation System inlet stack was characterized for particle penetration efficiency from 10 nm to 20 μm in diameter using duplicate scanning mobility particle sizers (10 nm-450 nm), ultra-high-sensitivity aerosol spectrometers (60 nm-μm), and aerodynamic particle sizers (0.5 μm-20 μm). Results show good model-measurement agreement and unit transmission efficiency of aerosols from 10 nm to 4 μm in diameter. Large uncertainties in the measured transmission efficiency exist above 4 μm due to low ambient aerosol signal in that size range.

  13. External-Compression Supersonic Inlet Design Code

    Science.gov (United States)

    Slater, John W.

    2011-01-01

    A computer code named SUPIN has been developed to perform aerodynamic design and analysis of external-compression, supersonic inlets. The baseline set of inlets include axisymmetric pitot, two-dimensional single-duct, axisymmetric outward-turning, and two-dimensional bifurcated-duct inlets. The aerodynamic methods are based on low-fidelity analytical and numerical procedures. The geometric methods are based on planar geometry elements. SUPIN has three modes of operation: 1) generate the inlet geometry from a explicit set of geometry information, 2) size and design the inlet geometry and analyze the aerodynamic performance, and 3) compute the aerodynamic performance of a specified inlet geometry. The aerodynamic performance quantities includes inlet flow rates, total pressure recovery, and drag. The geometry output from SUPIN includes inlet dimensions, cross-sectional areas, coordinates of planar profiles, and surface grids suitable for input to grid generators for analysis by computational fluid dynamics (CFD) methods. The input data file for SUPIN and the output file from SUPIN are text (ASCII) files. The surface grid files are output as formatted Plot3D or stereolithography (STL) files. SUPIN executes in batch mode and is available as a Microsoft Windows executable and Fortran95 source code with a makefile for Linux.

  14. Acoustic, Flow Related, and Performance Related Experimental Results for Generation 1.5 High Speed Civil Transport (HSCT) 2-Dimensional Exhaust Nozzles

    Science.gov (United States)

    Salikuddin, M.; Wisler, S.; Majjigi, R.

    2004-01-01

    The principle objectives of the current program were to experimentally investigate the repeatability of acoustic and aerodynamic characteristics of 2D-CD mixer-ejector nozzles and the effects on the acoustic and aerodynamic characteristics of 2D mixer-ejectors due to (1) the configurational variations, which include mixers with aligned CD chutes, aligned convergent chutes, and staggered CD chutes and aerodynamic cycle variables, (2) treatment variations by using different treatment materials, treating the ejector with varying area, location, and treatment thickness for a mixer-ejector configuration, and (3) secondary inlet shape (i.e., a more realistic inlet) and the blockage across the inlet (a possible fin-like structure needed for installation purpose) by modifying one of the inlet of a mixer-ejector configuration. The objectives also included the measurement dynamic pressures internal to the ejector for a few selected configuration to examine the internal noise characteristics.

  15. Jet noise suppression by porous plug nozzles

    Science.gov (United States)

    Bauer, A. B.; Kibens, V.; Wlezien, R. W.

    1982-01-01

    Jet noise suppression data presented earlier by Maestrello for porous plug nozzles were supplemented by the testing of a family of nozzles having an equivalent throat diameter of 11.77 cm. Two circular reference nozzles and eight plug nozzles having radius ratios of either 0.53 or 0.80 were tested at total pressure ratios of 1.60 to 4.00. Data were taken both with and without a forward motion or coannular flow jet, and some tests were made with a heated jet. Jet thrust was measured. The data were analyzed to show the effects of suppressor geometry on nozzle propulsive efficiency and jet noise. Aerodynamic testing of the nozzles was carried out in order to study the physical features that lead to the noise suppression. The aerodynamic flow phenomena were examined by the use of high speed shadowgraph cinematography, still shadowgraphs, extensive static pressure probe measurements, and two component laser Doppler velocimeter studies. The different measurement techniques correlated well with each other and demonstrated that the porous plug changes the shock cell structure of a standard nozzle into a series of smaller, periodic cell structures without strong shock waves. These structures become smaller in dimension and have reduced pressure variations as either the plug diameter or the porosity is increased, changes that also reduce the jet noise and decrease thrust efficiency.

  16. Fastrac Nozzle Design, Performance and Development

    Science.gov (United States)

    Peters, Warren; Rogers, Pat; Lawrence, Tim; Davis, Darrell; DAgostino, Mark; Brown, Andy

    2000-01-01

    With the goal of lowering the cost of payload to orbit, NASA/MSFC (Marshall Space Flight Center) researched ways to decrease the complexity and cost of an engine system and its components for a small two-stage booster vehicle. The composite nozzle for this Fastrac Engine was designed, built and tested by MSFC with fabrication support and engineering from Thiokol-SEHO (Science and Engineering Huntsville Operation). The Fastrac nozzle uses materials, fabrication processes and design features that are inexpensive, simple and easily manufactured. As the low cost nozzle (and injector) design matured through the subscale tests and into full scale hot fire testing, X-34 chose the Fastrac engine for the propulsion plant for the X-34. Modifications were made to nozzle design in order to meet the new flight requirements. The nozzle design has evolved through subscale testing and manufacturing demonstrations to full CFD (Computational Fluid Dynamics), thermal, thermomechanical and dynamic analysis and the required component and engine system tests to validate the design. The Fastrac nozzle is now in final development hot fire testing and has successfully accumulated 66 hot fire tests and 1804 seconds on 18 different nozzles.

  17. Development of repair mechanism of FSX-414 based 1st stage nozzle of gas turbine

    Science.gov (United States)

    Rahman, Md. Tawfiqur

    2017-06-01

    This paper describes the failure mechanism and repair technology of 1st stage nozzle or vane of industrial gas turbine which is made of cobalt based super alloy FSX-414. 1st stage nozzles or vanes are important stationery components of gas turbine based power plant. Those are the parts of hot gas path components of gas turbine and their manufacturing process is casting. At present, it is widely accepted that gas turbine based combined cycle power plant is the most efficient and cost effective solution to generate electricity. One of the factors of high efficiency of this type of gas turbine is the increase of its turbine inlet temperature. As an effect of this factor and in conjunction with some other factors, the 1st stage nozzle of gas turbine operates under extremely high temperature and thermal stresses. As a result, the design lifetime of these components becomes limited. Furthermore, attention on nozzles or vanes is required in order to achieve their design lifetime. However, due to unfriendly operational condition and environmental effect, anytime failure can occur on these heat resistant alloy based components which may lead to severe damage of gas turbine. To mitigate these adverse effects, schedule maintenance is performed on a predetermined time interval of hot gas path components of gas turbine based power plant. This paper addresses common failures in gas turbine's 1st stage nozzles or vanes. Usually these are repaired by using ADH process but for several reasons ADH process is not used here. Hence the challenging task is performed using gas tungsten arc welding which is presented in this article systematically.

  18. Transient Three-Dimensional Side Load Analysis of Out-of-Round Film Cooled Nozzles

    Science.gov (United States)

    Wang, Ten-See; Lin, Jeff; Ruf, Joe; Guidos, Mike

    2010-01-01

    The objective of this study is to investigate the effect of nozzle out-of-roundness on the transient startup side loads at a high altitude, with an anchored computational methodology. The out-of-roundness could be the result of asymmetric loads induced by hardware attached to the nozzle, asymmetric internal stresses induced by previous tests, and deformation, such as creep, from previous tests. The rocket engine studied encompasses a regeneratively cooled thrust chamber and a film cooled nozzle extension with film coolant distributed from a turbine exhaust manifold. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, and a transient inlet history based on an engine system simulation. Transient startup computations were performed with the out-of-roundness achieved by four different degrees of ovalization: one perfectly round, one slightly out-of-round, one more out-of-round, and one significantly out-of-round. The results show that the separation-line-jump is the peak side load physics for the round, slightly our-of-round, and more out-of-round cases, and the peak side load increases as the degree of out-of-roundness increases. For the significantly out-of-round nozzle, however, the peak side load reduces to comparable to that of the round nozzle and the separation line jump is not the peak side load physics. The counter-intuitive result of the significantly out-of-round case is found to be related to a side force reduction mechanism that splits the effect of the separation-line-jump into two parts, not only in the circumferential direction and most importantly in time.

  19. Coupled CFD-Thermal Analysis of Erosion Patterns Resulting from Nozzle Wedgeouts on the SRTMV-N2

    Science.gov (United States)

    Ables, Catherine; Davis, Philip

    2014-01-01

    The objective of this analysis was to study the effects of the erosion patterns from the introduction of nozzle flaws machined into the nozzle of the SRTMV-N2 (Solid Rocket Test Motor V Nozzle 2). The SRTMV-N2 motor was a single segment static subscale solid rocket motor used to further develop the RSRMV (Redesigned Solid Rocket Motor V Segment). Two flaws or "wedgeouts" were placed in the nozzle inlet parallel to the ply angles of that section to study erosion effects. One wedgeout was placed in the nose cap region and the other placed in the inlet ring on the opposite side of the bondline, separated 180 degrees circumferentially. A coupled CFD (Computational Fluid Analysis)-thermal iterative analytical approach was utilized at the wedgeouts to analyze the erosion profile during the burn time. The iterative CFD thermal approach was applied at five second intervals throughout the motor burn. The coupled fluid thermal boundary conditions were derived from a steady state CFD solution at the beginning of the interval. The derived heat fluxes were then applied along the surface and a transient thermal solution was developed to characterize the material response over the specified interval. Eroded profiles of each of the nozzle's wedgeouts and the original contour were created at each of the specified intervals. The final iteration of the erosion profile showed that both wedgeouts were "washedout," indicating that the erosion profile of the wedgeout had rejoined the original eroded contour, leaving no trace of the wedgeouts post fire. This analytical assessment agreed with post-fire observations made of the SRTMV-N2 wedgeouts, which noted a smooth eroded contour.

  20. Nuclear thermal rocket nozzle testing and evaluation program

    Science.gov (United States)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1993-01-01

    Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. The Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics are given. Results of pretest performance analyses show that high nozzle performance can be attained despite substantial nozzle length reduction through the use of plug nozzles as compared to a convergent-divergent nozzle. Pretest measurement uncertainty analyses indicate that specific impulse values are expected to be within + or - 1.17 pct.

  1. Method of cooling gas only nozzle fuel tip

    Science.gov (United States)

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  2. Integrated Composite Rocket Nozzle Extension Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate an Integrated Composite Rocket Nozzle Extension (ICRNE) for use in rocket thrust chambers. The ICRNE will utilize an...

  3. Numerical Study on Shape of Liquid Inlet for Venturi Scrubber in Self-Priming Mode

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. W.; Kim, H. S.; Kim, W. S. [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In this study, the simulation was developed for different design of liquid inlet to improve injection in submerged self-priming mode venturi scrubber. 1. A hole type is easy to discharged gas from liquid inlet for submerged self-priming mode. 2. A spit type, the liquid is injected into venturi scrubber for all gas volume rate in submerged self-priming mode. 3. A spit type is better than a hole type on improving injection of liquid inlet for submerged self-priming mode in venturi scrubber.The gas accelerate in convergent segment and reach maximum velocity at throat. The liquid is injected into venturi scrubber depends on static pressure difference between outside and inside of the venturi throat, then liquid is atomized into fine droplet when it contacts with high speed airflow. Aerosol removal occur in the diverging section as the inlet gas stream mixes with the fog of tiny liquid droplets. Many studies dealing with the non-submerged selfpriming venturi scrubber. In a non-submerged condition, outlet nozzle of venturi scrubber is not immersed in water pool of a tank whereas in a submerged condition, the outlet of a venturi scrubber is immersed in water pool. The scrubbing liquid is supplied by water reservoir surrounding the throat and is drawn in due to a pressure difference between the outside and the inside of the venturi throat that arises out of the hydrostatic pressure of the liquid and static pressure of the flowing gas. The performance of a venturi scrubber is improved with high gas velocities and high liquid flow rate. Therefore, it is important to study the liquid fraction in venturi scrubber operated at different condition. The venturi scrubber is used to a submerged self-priming mode because the system operates in a passive mode in CFVS. The present study focuses on the liquid flow characteristics for various shapes of liquid inlet in submerged self-priming venturi scrubber.

  4. Flow Energy Piezoelectric Bimorph Nozzle Harvester

    Science.gov (United States)

    Sherrit, Stewart (Inventor); Walkemeyer, Phillip E. (Inventor); Hall, Jeffrey L. (Inventor); Lee, Hyeong Jae (Inventor); Colonius, Tim (Inventor); Tosi, Phillipe (Inventor); Kim, Namhyo (Inventor); Sun, Kai (Inventor); Corbett, Thomas Gary (Inventor); Arrazola, Alvaro Jose (Inventor)

    2016-01-01

    A flow energy harvesting device having a harvester pipe includes a flow inlet that receives flow from a primary pipe, a flow outlet that returns the flow into the primary pipe, and a flow diverter within the harvester pipe having an inlet section coupled to the flow inlet, a flow constriction section coupled to the inlet section and positioned at a midpoint of the harvester pipe and having a spline shape with a substantially reduced flow opening size at a constriction point along the spline shape, and an outlet section coupled to the constriction section. The harvester pipe may further include a piezoelectric structure extending from the inlet section through the constriction section and point such that the fluid flow past the constriction point results in oscillatory pressure amplitude inducing vibrations in the piezoelectric structure sufficient to cause a direct piezoelectric effect and to generate electrical power for harvesting.

  5. F-15B ACTIVE with thrust vectoring nozzles on test stand view from rear

    Science.gov (United States)

    1995-01-01

    This November 13, 1995, photograph of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the aircraft's two new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. These nozzles give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. Ground testing of a new thrust-vectoring concept employing the nozzles took place during the first two weeks of November 1995 and went well, and flight tests began in March 1996. These tests could result in significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace.

  6. Gas Turbine Engine Inlet Wall Design

    Science.gov (United States)

    Florea, Razvan Virgil (Inventor); Matalanis, Claude G. (Inventor); Stucky, Mark B. (Inventor)

    2016-01-01

    A gas turbine engine has an inlet duct formed to have a shape with a first ellipse in one half and a second ellipse in a second half. The second half has an upstream most end which is smaller than the first ellipse. The inlet duct has a surface defining the second ellipse which curves away from the first ellipse, such that the second ellipse is larger at an intermediate location. The second ellipse is even larger at a downstream end of the inlet duct leading into a fan.

  7. Design of a new type vapor recovery system nozzle

    Science.gov (United States)

    Fu, S. H.; Cao, G. J.; Zhang, D. S.

    2016-05-01

    To settle the problem of low-efficiency recovery for Vapor recovery system nozzle, this paper advances a purely mechanical structure of the self-sealing refueling VRS nozzle. The structure, operating principle and controlled process of the nozzle is given. And an application of the nozzle is discussed. All indicated that the nozzle has a reasonable structure, can fuel and vapor recovery simultaneous start and stop. And thus improve the recovery efficiency and reduce oil leakage.

  8. Calibrating feedwater flow nozzles in-situ

    Energy Technology Data Exchange (ETDEWEB)

    Caudill, M. [Tri-State Generation and Transmission, Inc., Montrose, CA (United States); Diaz-Tous, I.; Murphy, S.; Leggett, M.; Crandall, C. [ENCOR-AMERICA, Inc., Mountain View, CA (United States)

    1996-05-01

    This paper presents a new method for in-situ calibration of feedwater flow nozzles wherein feedwater flow is determined indirectly by performing a high accuracy heat balance around the highest-pressure feedwater heater. It is often difficult to reliably measure feedwater flow. Over the life of a power plant, the feedwater nozzle can accumulate deposits, erode, or suffer other damage that can render the original nozzle calibration inaccurate. Recalibration of installed feedwater flow nozzles is expensive and time consuming. Traditionally, the nozzle is cut out of the piping and sent to a laboratory for recalibration, which can be an especially difficult, expensive, and time-consuming task when involving high pressure feedwater lines. ENCOR-AMERICA, INC. has developed an accurate and cost-effective method of calibrating feedwater nozzles in-situ as previously reported at the 1994 EPRI Heat Rate Improvement Conference. In this method, feedwater flow and differential pressure across the nozzle are measured concurrently. The feedwater flow is determined indirectly by performing a heat balance around the highest-pressure feedwater heater. Extraction steam to the feedwater heater is measured by use of a high accuracy turbine flowmeter. The meters used have been calibrated at an independent laboratory with a primary or secondary device traceable to the NIST. In this paper, a new variation on the above method is reported. The new approach measures the heater drains and vent flows instead of the extraction steam flow. Test theory and instrumentation will be discussed. Results of in-situ feedwater nozzle calibration tests performed at two units owned by Tri-State Generation and Transmission Association will be presented.

  9. An Experimental Investigation of the Aeroacoustics of a Two-Dimensional Bifurcated Supersonic Inlet

    Science.gov (United States)

    LI, S.-M.; HANUSKA, C. A.; NG, W. F.

    2001-11-01

    An experiment was conducted on a two-dimensional bifurcated, supersonic inlet to investigate the aeroacoustics at take-off and landing conditions. A 104·1 mm (4·1 in) diameter turbofan simulator was coupled to the inlet to generate the noise typical of a turbofan engine. Aerodynamic and acoustic data were obtained in an anechoic chamber under ground-static conditions (i.e., no forward flight effect). Results showed that varying the distance between the trailing edge of the bifurcated ramp of the inlet and the fan face had negligible effect on the total noise level. Thus, one can have a large freedom to design the bifurcated ramp mechanically and aerodynamically, with minimum impact on the aeroacoustics. However, the effect of inlet guide vanes' (IGV) axial spacing to the fan face has a first order effect on the aeroacoustics for the bifurcated 2-D inlet. As much as 5 dB reduction in the overall sound pressure level and as much as 15 dB reduction in the blade passing frequency tone were observed when the IGV was moved from 0·8 chord of rotor blade upstream of the fan face to 2·0 chord of the blade upstream. The wake profile similarity of the IGV was also found in the flow environment of the 2-D bifurcated inlet, i.e., the IGV wakes followed the usual Gauss' function.

  10. Annual report, Cook Inlet District, 1958 season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Commercial fishery management activities for Cook Inlet and Resurrection Bay for 1958, including lists of operators and extensive statistics.

  11. Annual report, Cook Inlet District, 1956 season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Commercial fishery management activities for Cook Inlet and Resurrection Bay for 1956, including lists of operators and extensive statistics.

  12. Annual report, Cook Inlet District, 1954 season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Commercial fishery management activities for Cook Inlet and Resurrection Bay for 1954, including lists of operators and extensive statistics.

  13. Annual report, Cook Inlet District, 1957 season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Commercial fishery management activities for Cook Inlet and Resurrection Bay for 1957, including lists of operators and extensive statistics.

  14. Annual report, Cook Inlet District, 1959 season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Commercial fishery management activities for Cook Inlet and Resurrection Bay for 1959, including lists of operators and extensive statistics.

  15. Interactions Between Wetlands and Tidal Inlets

    Science.gov (United States)

    2008-08-01

    Madre, TX), (3) fjord-type (e.g., Penobscot Bay , ME), and (4) tectonically created estuaries (e.g., San Francisco Bay , CA) (Pritchard 1967). This CHETN...small marsh island in San Francisco Bay , CA. Wolaver et al. (1988) measured suspended sediment flux of 827 g/m2/year into a marsh in North Inlet, SC...permanent or ephemeral inlets. Conversely, the development or construction of wetlands within an estuary reduces bay area and the tidal prism, which will

  16. Parametric study of solar thermal rocket nozzle performance

    Science.gov (United States)

    Pearson, J. Boise; Landrum, D. Brian; Hawk, Clark W.

    1995-01-01

    This paper details a numerical investigation of performance losses in low-thrust solar thermal rocket nozzles. The effects of nozzle geometry on three types of losses were studied; finite rate dissociation-recombination kinetic losses, two dimensional axisymmetric divergence losses, and compressible viscous boundary layer losses. Short nozzle lengths and supersonic flow produce short residence times in the nozzle and a nearly frozen flow, resulting in large kinetic losses. Variations in geometry have a minimal effect on kinetic losses. Divergence losses are relatively small, and careful shaping of the nozzle can nearly eliminate them. The boundary layer in these small nozzles can grow to a major fraction of nozzle radius, and cause large losses. These losses are attributed to viscous drag on the nozzle walls and flow blockage by the boundary layer, especially in the throat region. Careful shaping of the nozzle can produce a significant reduction in viscous losses.

  17. Nozzle assembly for an earth boring drill bit

    Energy Technology Data Exchange (ETDEWEB)

    Madigan, J. A.

    1985-09-24

    A nozzle assembly for an earth boring drill bit of the type adapted to receive drilling fluid under pressure and having a nozzle bore in the bottom thereof positioned closely adjacent the well bore bottom when the bit is in engagement therewith with the bore having inner and outer portions. The nozzle assembly comprises a generally cylindrical nozzle member of abrasion and erosion resistant material, selected from a plurality of such members, each being of the same outer diameter but having passaging therein of different cross-sectional area. The nozzle member is adapted to be fitted in the inner portion of the nozzle bore in sealing relationship therewith for forming a first seal for the nozzle assembly. The nozzle assembly further comprises a locknut, separate from the nozzle member, for detachbably securing the nozzle member in the nozzle bore, formed at least in part of an abrasion and erosion resistant material. The locknut has a threaded side wall engageable with the outer portion of the nozzle bore, and an aperture therethrough for enabling a stream of drilling fluid from the nozzle member to flow therethrough and being so configured in section as to receive a tool for turning the lockout to install it in and remove it from the nozzle bore.

  18. Upper Stage Engine Composite Nozzle Extensions

    Science.gov (United States)

    Valentine, Peter G.; Allen, Lee R.; Gradl, Paul R.; Greene, Sandra E.; Sullivan, Brian J.; Weller, Leslie J.; Koenig, John R.; Cuneo, Jacques C.; Thompson, James; Brown, Aaron; hide

    2015-01-01

    Carbon-carbon (C-C) composite nozzle extensions are of interest for use on a variety of launch vehicle upper stage engines and in-space propulsion systems. The C-C nozzle extension technology and test capabilities being developed are intended to support National Aeronautics and Space Administration (NASA) and United States Air Force (USAF) requirements, as well as broader industry needs. Recent and on-going efforts at the Marshall Space Flight Center (MSFC) are aimed at both (a) further developing the technology and databases for nozzle extensions fabricated from specific CC materials, and (b) developing and demonstrating low-cost capabilities for testing composite nozzle extensions. At present, materials development work is concentrating on developing a database for lyocell-based C-C that can be used for upper stage engine nozzle extension design, modeling, and analysis efforts. Lyocell-based C-C behaves in a manner similar to rayon-based CC, but does not have the environmental issues associated with the use of rayon. Future work will also further investigate technology and database gaps and needs for more-established polyacrylonitrile- (PAN-) based C-C's. As a low-cost means of being able to rapidly test and screen nozzle extension materials and structures, MSFC has recently established and demonstrated a test rig at MSFC's Test Stand (TS) 115 for testing subscale nozzle extensions with 3.5-inch inside diameters at the attachment plane. Test durations of up to 120 seconds have been demonstrated using oxygen/hydrogen propellants. Other propellant combinations, including the use of hydrocarbon fuels, can be used if desired. Another test capability being developed will allow the testing of larger nozzle extensions (13.5- inch inside diameters at the attachment plane) in environments more similar to those of actual oxygen/hydrogen upper stage engines. Two C-C nozzle extensions (one lyocell-based, one PAN-based) have been fabricated for testing with the larger

  19. Integrity of the Plasma Magnetic Nozzle

    Science.gov (United States)

    Gerwin, Richard A.

    2009-01-01

    This report examines the physics governing certain aspects of plasma propellant flow through a magnetic nozzle, specifically the integrity of the interface between the plasma and the nozzle s magnetic field. The injection of 100s of eV plasma into a magnetic flux nozzle that converts thermal energy into directed thrust is fundamental to enabling 10 000s of seconds specific impulse and 10s of kW/kg specific power piloted interplanetary propulsion. An expression for the initial thickness of the interface is derived and found to be approx.10(exp -2) m. An algorithm is reviewed and applied to compare classical resistivity to gradient-driven microturbulent (anomalous) resistivity, in terms of the spatial rate and time integral of resistive interface broadening, which can then be related to the geometry of the nozzle. An algorithm characterizing plasma temperature, density, and velocity dependencies is derived and found to be comparable to classical resistivity at local plasma temperatures of approx. 200 eV. Macroscopic flute-mode instabilities in regions of "adverse magnetic curvature" are discussed; a growth rate formula is derived and found to be one to two e-foldings of the most unstable Rayleigh-Taylor (RT) mode. After establishing the necessity of incorporating the Hall effect into Ohm s law (allowing full Hall current to flow and concomitant plasma rotation), a critical nozzle length expression is derived in which the interface thickness is limited to about 1 ion gyroradius.

  20. Compressible vortex loops: Effect of nozzle geometry

    Energy Technology Data Exchange (ETDEWEB)

    Zare-Behtash, H. [School of MACE, University of Manchester, M60 1QD (United Kingdom)], E-mail: h.zare-behtash@postgrad.manchester.ac.uk; Kontis, K. [School of MACE, University of Manchester, M60 1QD (United Kingdom)], E-mail: k.kontis@manchester.ac.uk; Gongora-Orozco, N. [School of MACE, University of Manchester, M60 1QD (United Kingdom); Takayama, K. [Tohoku University, Shock Wave Research Centre, Sendai 980-8577 (Japan)

    2009-06-15

    Vortex loops are fundamental building blocks of supersonic free jets. Isolating them allows for an easier study and better understanding of such flows. The present study looks at the behaviour of compressible vortex loops of different shapes, generated due to the diffraction of a shock wave from a shock tube with different exit nozzle geometries. These include a 15 mm diameter circular nozzle, two elliptical nozzles with minor to major axis ratios of 0.4 and 0.6, a 30 x 30 mm square nozzle, and finally two exotic nozzles resembling a pair of lips with minor to major axis ratios of 0.2 and 0.5. The experiments were performed for diaphragm pressure ratios of P{sub 4}/P{sub 1}=4, 8, and 12, with P{sub 4} and P{sub 1} being the pressures within the high pressure and low pressure compartments of the shock tube, respectively. High-speed schlieren photography as well as PIV measurements of both stream-wise and head-on flows have been conducted.

  1. Biannular Airbreathing Nozzle Rig (BANR) facility checkout and plug nozzle performance test data

    Science.gov (United States)

    Cummings, Chase B.

    2010-09-01

    The motivation for development of a supersonic business jet (SSBJ) platform lies in its ability to create a paradigm shift in the speed and reach of commercial, private, and government travel. A full understanding of the performance capabilities of exhaust nozzle configurations intended for use in potential SSBJ propulsion systems is critical to the design of an aircraft of this type. Purdue University's newly operational Biannular Airbreathing Nozzle Rig (BANR) is a highly capable facility devoted to the testing of subscale nozzles of this type. The high accuracy, six-axis force measurement system and complementary mass flowrate measurement capabilities of the BANR facility make it rather ideally suited for exhaust nozzle performance appraisal. Detailed accounts pertaining to methods utilized in the proper checkout of these diagnostic capabilities are contained herein. Efforts to quantify uncertainties associated with critical BANR test measurements are recounted, as well. Results of a second hot-fire test campaign of a subscale Gulfstream Aerospace Corporation (GAC) axisymmetric, shrouded plug nozzle are presented. Determined test article performance parameters (nozzle thrust efficiencies and discharge coefficients) are compared to those of a previous test campaign and numerical simulations of the experimental set-up. Recently acquired data is compared to published findings pertaining to plug nozzle experiments of similar scale and operating range. Suggestions relating to the future advancement and improvement of the BANR facility are provided. Lessons learned with regards to test operations and calibration procedures are divulged in an attempt to aid future facility users, as well.

  2. Experimental investigation of flow through planar double divergent nozzles

    Science.gov (United States)

    Arora, Rajat; Vaidyanathan, Aravind

    2015-07-01

    Dual bell nozzle is one of the feasible and cost effective techniques for altitude adaptation. Planar double divergent nozzle with a rectangular cross section was designed for two different NPR's to simulate and investigate the flow regimes similar to those inside the dual bell nozzle. Measurements involved flow visualization using Schlieren technique and wall static pressure measurements. The flow transition between the two nozzles at the respective inflection points and the formation of recirculation region due to flow separation was analyzed in detail. Cold flow tests were performed on the double divergent nozzle in the over-expanded conditions to study the shock wave characteristics. The results obtained from the two independent double divergent nozzles were compared with those obtained from a single divergent nozzle of the same area ratio. From the experiments it was observed that inflection angle played a key role in defining the type of shock structures existing inside the double divergent nozzles.

  3. Lightweight Nozzle Extension for Liquid Rocket Engines Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The ARES J-2X requires a large nozzle extension. Currently, a metallic nozzle extension is being considered with carbon-carbon composite as a backup. In Phase 1,...

  4. Influences of flow loss and inlet distortions from radial inlets on the performances of centrifugal compressor stages

    Energy Technology Data Exchange (ETDEWEB)

    Han, Feng Hui; Mao, Yi Jun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an (China); Tan, Ji Jian [Dept. of Research and Development, Shenyang Blower Works Group Co., Ltd., Shenyang (China)

    2016-11-15

    Radial inlets are typical upstream components of multistage centrifugal compressors. Unlike axial inlets, radial inlets generate additional flow loss and introduce flow distortions at impeller inlets. Such distortions negatively affect the aerodynamic performance of compressor stages. In this study, industrial centrifugal compressor stages with different radial inlets are investigated via numerical simulations. Two reference models were built, simulated, and compared with each original compressor stage to analyze the respective and coupling influences of flow loss and inlet distortions caused by radial inlets on the performances of the compressor stage and downstream components. Flow loss and inlet distortions are validated as the main factors through which radial inlets negatively affect compressor performance. Results indicate that flow loss inside radial inlets decreases the performance of the whole compressor stage but exerts minimal effect on downstream components. By contrast, inlet distortions induced by radial inlets negatively influence the performance of the whole compressor stage and exert significant effects on downstream components. Therefore, when optimizing radial inlets, the reduction of inlet distortions might be more effective than the reduction of flow loss. This research provides references and suggestions for the design and improvement of radial inlets.

  5. Noise of Embedded High Aspect Ratio Nozzles

    Science.gov (United States)

    Bridges, James E.

    2011-01-01

    A family of high aspect ratio nozzles were designed to provide a parametric database of canonical embedded propulsion concepts. Nozzle throat geometries with aspect ratios of 2:1, 4:1, and 8:1 were chosen, all with convergent nozzle areas. The transition from the typical round duct to the rectangular nozzle was designed very carefully to produce a flow at the nozzle exit that was uniform and free from swirl. Once the basic rectangular nozzles were designed, external features common to embedded propulsion systems were added: extended lower lip (a.k.a. bevel, aft deck), differing sidewalls, and chevrons. For the latter detailed Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) simulations were made to predict the thrust performance and to optimize parameters such as bevel length, and chevron penetration and azimuthal curvature. Seventeen of these nozzles were fabricated at a scale providing a 2.13 inch diameter equivalent area throat." ! The seventeen nozzles were tested for far-field noise and a few data were presented here on the effect of aspect ratio, bevel length, and chevron count and penetration. The sound field of the 2:1 aspect ratio rectangular jet was very nearly axisymmetric, but the 4:1 and 8:1 were not, the noise on their minor axes being louder than the major axes. Adding bevel length increased the noise of these nozzles, especially on their minor axes, both toward the long and short sides of the beveled nozzle. Chevrons were only added to the 2:1 rectangular jet. Adding 4 chevrons per wide side produced some decrease at aft angles, but increased the high frequency noise at right angles to the jet flow. This trend increased with increasing chevron penetration. Doubling the number of chevrons while maintaining their penetration decreased these effects. Empirical models of the parametric effect of these nozzles were constructed and quantify the trends stated above." Because it is the objective of the Supersonics Project that

  6. CFD Analysis On The Performance Of Wind Turbine With Nozzles

    Directory of Open Access Journals (Sweden)

    Chunkyraj Kh

    2015-08-01

    Full Text Available In this paper an effort has been made in dealing with fluid characteristic that enters a converging nozzle and analysis of the nozzle is carried out using Computational Fluid Dynamics package ANSYS WORKBENCH 14.5. The paper is the continuation of earlier work Analytical and Experimental performance evaluation of Wind turbine with Nozzles. First the CFD analysis will be carried out on nozzle in-front of wind turbine where streamline velocity at the exit volume flow rate in the nozzle and pressure distribution across the nozzle will be studied. Experiments were conducted on the Wind turbine with nozzles and the corresponding power output at different air speed and different size of nozzles were calculated. Different shapes and dimensions with special contours and profiles of nozzles were studied. It was observed that the special contour nozzles have superior outlet velocity and low pressure at nozzle exit the design has maximum Kinetic energy. These indicators conclude that the contraction designed with the new profile is a good enhancing of the nozzle performance.

  7. Internal performance characteristics of vectored axisymmetric ejector nozzles

    Science.gov (United States)

    Lamb, Milton

    1993-01-01

    A series of vectoring axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at NASA-Langley Research Center. These ejector nozzles used convergent-divergent nozzles as the primary nozzles. The model geometric variables investigated were primary nozzle throat area, primary nozzle expansion ratio, effective ejector expansion ratio (ratio of shroud exit area to primary nozzle throat area), ratio of minimum ejector area to primary nozzle throat area, ratio of ejector upper slot height to lower slot height (measured on the vertical centerline), and thrust vector angle. The primary nozzle pressure ratio was varied from 2.0 to 10.0 depending upon primary nozzle throat area. The corrected ejector-to-primary nozzle weight-flow ratio was varied from 0 (no secondary flow) to approximately 0.21 (21 percent of primary weight-flow rate) depending on ejector nozzle configuration. In addition to the internal performance and pumping characteristics, static pressures were obtained on the shroud walls.

  8. Integrated Ceramic Matrix Composite and Carbon/Carbon Structures for Large Rocket Engine Nozzles and Nozzle Extensions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Low-cost access to space demands durable, cost-effective, efficient, and low-weight propulsion systems. Key components include rocket engine nozzles and nozzle...

  9. Aggregate breakup in a contracting nozzle.

    Science.gov (United States)

    Soos, Miroslav; Ehrl, Lyonel; Bäbler, Matthäus U; Morbidelli, Massimo

    2010-01-05

    The breakup of dense aggregates in an extensional flow was investigated experimentally. The flow was realized by pumping the suspension containing the aggregates through a contracting nozzle. Variation of the cluster mass distribution during the breakage process was measured by small-angle light scattering. Because of the large size of primary particles and the dense aggregate structure image analysis was used to determine the shape and structure of the produced fragments. It was found, that neither aggregate structure, characterized by a fractal dimension d(f) = 2.7, nor shape, characterized by an average aspect ratio equal to 1.5, was affected by breakage. Several passes through the nozzle were required to reach the steady state. This is explained by the radial variation of the hydrodynamic stresses at the nozzle entrance, characterized through computational fluid dynamics, which implies that only the fraction of aggregates whose strength is smaller than the local hydrodynamic stress is broken during one pass through the nozzle. Scaling of the steady-state aggregate size as a function of the hydrodynamic stress was used to determine the aggregate strength.

  10. Orbiter Water Dump Nozzles Redesign Lessons Learned

    Science.gov (United States)

    Rotter, Hank

    2017-01-01

    Hank Rotter, NASA Technical Fellow for Environmental Control and Life Support System, will provide the causes and lessons learned for the two Space Shuttle Orbiter water dump icicles that formed on the side of the Orbiter. He will present the root causes and the criticality of these icicles, along with the redesign of the water dump nozzles and lessons learned during the redesign phase.

  11. New atomization nozzle for spray drying

    NARCIS (Netherlands)

    Deventer, H.C. van; Houben, R.J.; Koldeweij, R.B.J.

    2013-01-01

    A new atomization nozzle based on ink jet technology is introduced for spray drying. Application areas are the food and dairy industry, in the first instance, because in these industries the quality demands on the final powders are high with respect to heat load, powder shape, and size distribution.

  12. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti (

  13. Microalgal cell disruption via ultrasonic nozzle spraying.

    Science.gov (United States)

    Wang, M; Yuan, W

    2015-01-01

    The objective of this study was to understand the effect of operating parameters, including ultrasound amplitude, spraying pressure, nozzle orifice diameter, and initial cell concentration on microalgal cell disruption and lipid extraction in an ultrasonic nozzle spraying system (UNSS). Two algal species including Scenedesmus dimorphus and Nannochloropsis oculata were evaluated. Experimental results demonstrated that the UNSS was effective in the disruption of microalgal cells indicated by significant changes in cell concentration and Nile red-stained lipid fluorescence density between all treatments and the control. It was found that increasing ultrasound amplitude generally enhanced cell disruption and lipid recovery although excessive input energy was not necessary for best results. The effect of spraying pressure and nozzle orifice diameter on cell disruption and lipid recovery was believed to be dependent on the competition between ultrasound-induced cavitation and spraying-generated shear forces. Optimal cell disruption was not always achieved at the highest spraying pressure or biggest nozzle orifice diameter; instead, they appeared at moderate levels depending on the algal strain and specific settings. Increasing initial algal cell concentration significantly reduced cell disruption efficiency. In all UNSS treatments, the effectiveness of cell disruption and lipid recovery was found to be dependent on the algal species treated.

  14. New atomization nozzle for spray drying

    NARCIS (Netherlands)

    Deventer, H.C. van; Houben, R.J.; Koldeweij, R.B.J.

    2013-01-01

    A new atomization nozzle based on ink jet technology is introduced for spray drying. Application areas are the food and dairy industry, in the first instance, because in these industries the quality demands on the final powders are high with respect to heat load, powder shape, and size distribution.

  15. Shock wave fabricated ceramic-metal nozzles

    NARCIS (Netherlands)

    Carton, E.P.; Stuivinga, M.E.C.; Keizers, H.L.J.; Verbeek, H.J.; Put, P.J. van der

    1999-01-01

    Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti

  16. Fabrication of Microglass Nozzle for Microdroplet Jetting

    Directory of Open Access Journals (Sweden)

    Dan Xie

    2015-02-01

    Full Text Available An ejection aperture nozzle is the essential part for all microdrop generation techniques. The diameter size, the flow channel geometry, and fluid impedance are the key factors affecting the ejection capacity. A novel low-cost fabrication method of microglass nozzle involving four steps is developed in this work. In the first heating step, the glass pipette is melted and pulled. Then, the second heating step is to determine the tip cone angle and modify the flow channel geometry. The desired included angle is usually of 30~45 degrees. Fine grind can determine the exact diameter of the hole. Postheating step is the final process and it can reduce the sharpness of the edges of the hole. Micronozzles with hole diameters varying from 30 to 100 µm are fabricated by the homemade inexpensive and easy-to-operate setup. Hydrophobic treating method of microglass nozzle to ensure stable and accurate injection is also introduced in this work. According to the jetting results of aqueous solution, UV curing adhesive, and solder, the fabricated microglass nozzle can satisfy the need of microdroplet jetting of multimaterials.

  17. Cold water inlet in solar tanks - valuation

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the ratio...

  18. Miniature piezo electric vacuum inlet valve

    Science.gov (United States)

    Keville, Robert F.; Dietrich, Daniel D.

    1998-03-24

    A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

  19. Experimental and CFD analysis of nozzle position of subsonic ejector

    Institute of Scientific and Technical Information of China (English)

    Xilai ZHANG; Shiping JIN; Suyi HUANG; Guoqing TIAN

    2009-01-01

    The influence of nozzle position on the performance of an ejector was analyzed qualitatively with free jet flow model. Experimental investigations and computational fluid dynamics (CFD) analysis of the nozzle position of the subsonic ejector were also conducted. The results show that there is an optimum nozzle position for the ejector. The ejecting coefficient reaches its maximum when the nozzle is positioned at the optimum and decreases when deviating. Moreover, the nozzle position of an ejector is not a fixed value, but is influenced greatly by the flow parameters. Considering the complexity of the ejector, CFD is reckoned as a useful tool in the design of ejectors.

  20. Computational Fluid Dynamics Simulation of Dual Bell Nozzle Film Cooling

    Science.gov (United States)

    Braman, Kalen; Garcia, Christian; Ruf, Joseph; Bui, Trong

    2015-01-01

    Marshall Space Flight Center (MSFC) and Armstrong Flight Research Center (AFRC) are working together to advance the technology readiness level (TRL) of the dual bell nozzle concept. Dual bell nozzles are a form of altitude compensating nozzle that consists of two connecting bell contours. At low altitude the nozzle flows fully in the first, relatively lower area ratio, nozzle. The nozzle flow separates from the wall at the inflection point which joins the two bell contours. This relatively low expansion results in higher nozzle efficiency during the low altitude portion of the launch. As ambient pressure decreases with increasing altitude, the nozzle flow will expand to fill the relatively large area ratio second nozzle. The larger area ratio of the second bell enables higher Isp during the high altitude and vacuum portions of the launch. Despite a long history of theoretical consideration and promise towards improving rocket performance, dual bell nozzles have yet to be developed for practical use and have seen only limited testing. One barrier to use of dual bell nozzles is the lack of control over the nozzle flow transition from the first bell to the second bell during operation. A method that this team is pursuing to enhance the controllability of the nozzle flow transition is manipulation of the film coolant that is injected near the inflection between the two bell contours. Computational fluid dynamics (CFD) analysis is being run to assess the degree of control over nozzle flow transition generated via manipulation of the film injection. A cold flow dual bell nozzle, without film coolant, was tested over a range of simulated altitudes in 2004 in MSFC's nozzle test facility. Both NASA centers have performed a series of simulations of that dual bell to validate their computational models. Those CFD results are compared to the experimental results within this paper. MSFC then proceeded to add film injection to the CFD grid of the dual bell nozzle. A series of

  1. Flow Control in a Compact Inlet

    Science.gov (United States)

    Vaccaro, John C.

    2011-12-01

    An experimental investigation of flow control, via various control jets actuators, was undertaken to eliminate separation and secondary flows in a compact inlet. The compact inlet studied was highly aggressive with a length-to-diameter ratio of 1.5. A brand new facility was designed and built to enable various actuation methodologies as well as multiple measurement techniques. Techniques included static surface pressure, total pressure, and stereoscopic particle image velocimetry. Experimental data were supplemented with numerical simulations courtesy of Prof. Kenneth Jansen, Dr. Onkar Sahni, and Yi Chen. The baseline flow field was found to be dominated by two massive separations and secondary flow structures. These secondary structures were present at the aerodynamic interface plane in the form of two counter-rotating vortices inducing upwash along centerline. A dominant shedding frequency of 350 Hz was measured both at the aerodynamic interface plane and along the lower surface of the inlet. Flow control experiments started utilizing a pair of control jets placed in streamwise locations where flow was found to separate. Tests were performed for a range of inlet Mach numbers from 0.2 to 0.44. Steady and unsteady static pressure measurements along the upper and lower walls of the duct were performed for various combinations of actuation. The parameters that were tested include the control jets momentum coefficient, their blowing ratio, the actuation frequency, as well as different combinations of jets. It was shown that using mass flux ratio as a criterion to define flow control is not sufficient, and one needs to provide both the momentum coefficient and the blowing ratio to quantify the flow control performance. A detailed study was undertaken on controlling the upstream separation point for an inlet Mach number of 0.44. Similar to the baseline flow field, the flow field associated with the activation of a two-dimensional control jet actuator was dominated by

  2. PDE Nozzle Optimization Using a Genetic Algorithm

    Science.gov (United States)

    Billings, Dana; Turner, James E. (Technical Monitor)

    2000-01-01

    Genetic algorithms, which simulate evolution in natural systems, have been used to find solutions to optimization problems that seem intractable to standard approaches. In this study, the feasibility of using a GA to find an optimum, fixed profile nozzle for a pulse detonation engine (PDE) is demonstrated. The objective was to maximize impulse during the detonation wave passage and blow-down phases of operation. Impulse of each profile variant was obtained by using the CFD code Mozart/2.0 to simulate the transient flow. After 7 generations, the method has identified a nozzle profile that certainly is a candidate for optimum solution. The constraints on the generality of this possible solution remain to be clarified.

  3. Composite nozzle design for reactor fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Marlatt, G.R.; Allison, D.K.

    1984-01-24

    A composite nozzle is described for a fuel assembly adapted for installation on the upper or lower end thereof and which is constructed from two components. The first component includes a casting weldment or forging designed to carry handling loads, support fuel assembly weight and flow loads, and interface with structural members of both the fuel assembly and reactor internal structures. The second component of the nozzle consists of a thin stamped bore machine flow plate adapted for attachment to the casting body. The plate is designed to prevent fuel rods from being ejected from the core and provide orifices for coolant flow to a predetermined value and pressure drop which is consistent with the flow at other locations in the core.

  4. Numerical Investigation of Near-Field Plasma Flows in Magnetic Nozzles

    Science.gov (United States)

    Sankaran, Kamesh; Polzin, Kurt A.

    2009-01-01

    The development and application of a multidimensional numerical simulation code for investigating near-field plasma processes in magnetic nozzles are presented. The code calculates the time-dependent evolution of all three spatial components of both the magnetic field and velocity in a plasma flow, and includes physical models of relevant transport phenomena. It has been applied to an investigation of the behavior of plasma flows found in high-power thrusters, employing a realistic magnetic nozzle configuration. Simulation of a channel-flow case where the flow was super-Alfvenic has demonstrated that such a flow produces adequate back-emf to significantly alter the shape of the total magnetic field, preventing the flow from curving back to the magnetic field coil in the near-field region. Results from this simulation can be insightful in predicting far-field behavior and can be used as a set of self-consistent boundary conditions for far-field simulations. Future investigations will focus on cases where the inlet flow is sub-Alfvenic and where the flow is allowed to freely expand in the radial direction once it is downstream of the coil.

  5. Jet Engine Exhaust Nozzle Flow Effector

    Science.gov (United States)

    Turner, Travis L. (Inventor); Cano, Roberto J. (Inventor); Silox, Richard J. (Inventor); Buehrle, Ralph D. (Inventor); Cagle, Christopher M. (Inventor); Cabell, Randolph H. (Inventor); Hilton, George C. (Inventor)

    2014-01-01

    A jet engine exhaust nozzle flow effector is a chevron formed with a radius of curvature with surfaces of the flow effector being defined and opposing one another. At least one shape memory alloy (SMA) member is embedded in the chevron closer to one of the chevron's opposing surfaces and substantially spanning from at least a portion of the chevron's root to the chevron's tip.

  6. Dual Nozzle Aerodynamic and Cooling Analysis Study.

    Science.gov (United States)

    1981-02-27

    ALRC Irwin Alber , Consultant Jim Duey, ALRC Joe Hoffman, Purdue University This report presents the Summary, Section I - Introduction, Section II...SCISEARCH. Papers which referred to the works of Korst, Bauer, and Alber were sought in this way. 19 I III, A, Literature Survey (cont.) The second...Point ’rfil Fna! ’w Turnino Annie Wall Anile at Attachrient Pnint hpar I ivPr ’hir r, ,ioz f Nnze Area Datioi P - Primary Nozzle Throa! Radius F Pati

  7. Modelling Complex Inlet Geometries in CFD

    DEFF Research Database (Denmark)

    Skovgaard, M.; Nielsen, Peter V.

    Modem inlet devices applied in the field of ventilation of rooms are getting more complex in terms of geometry in order to fulfil the occupants' demand for thermal comfort in the room and in order to decrease the energy consumption. This expresses the need for a more precise calculation of the fl...... and tested. The method is based upon threedimensional - and radial wall jet theory and upon diffuser specific experimental data....

  8. Coherent structures in a supersonic complex nozzle

    Science.gov (United States)

    Magstadt, Andrew; Berry, Matthew; Glauser, Mark

    2016-11-01

    The jet flow from a complex supersonic nozzle is studied through experimental measurements. The nozzle's geometry is motivated by future engine designs for high-performance civilian and military aircraft. This rectangular jet has a single plane of symmetry, an additional shear layer (referred to as a wall jet), and an aft deck representative of airframe integration. The core flow operates at a Mach number of Mj , c = 1 . 6 , and the wall jet is choked (Mj , w = 1 . 0). This high Reynolds number jet flow is comprised of intense turbulence levels, an intricate shock structure, shear and boundary layers, and powerful corner vortices. In the present study, stereo PIV measurements are simultaneously sampled with high-speed pressure measurements, which are embedded in the aft deck, and far-field acoustics in the anechoic chamber at Syracuse University. Time-resolved schlieren measurements have indicated the existence of strong flow events at high frequencies, at a Strouhal number of St = 3 . 4 . These appear to result from von Kàrmàn vortex shedding within the nozzle and pervade the entire flow and acoustic domain. Proper orthogonal decomposition is applied on the current data to identify coherent structures in the jet and study the influence of this vortex street. AFOSR Turbulence and Transition Program (Grant No. FA9550-15-1-0435) with program managers Dr. I. Leyva and Dr. R. Ponnappan.

  9. Flow Energy Piezoelectric Bimorph Nozzle Harvester

    Science.gov (United States)

    Sherrit, Stewart; Lee, Hyeong Jae; Kim, Namhyo; Sun, Kai; Corbett, Gary; Walkemeyer, Phillip; Hasenoehrl, Jennifer; Hall, Jeffery L.; Colonius, Tim; Tosi, Luis Phillipe; Arrazola, Alvaro

    2014-01-01

    There is a need for a long-life power generation scheme that could be used downhole in an oil well to produce 1 Watt average power. There are a variety of existing or proposed energy harvesting schemes that could be used in this environment but each of these has its own limitations. The vibrating piezoelectric structure is in principle capable of operating for very long lifetimes (decades) thereby possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. In order to determine the feasibility of using piezoelectrics to produce suitable flow energy harvesting, we surveyed experimentally a variety of nozzle configurations that could be used to excite a vibrating piezoelectric structure in such a way as to enable conversion of flow energy into useful amounts of electrical power. These included reed structures, spring mass-structures, drag and lift bluff bodies and a variety of nozzles with varying flow profiles. Although not an exhaustive survey we identified a spline nozzle/piezoelectric bimorph system that experimentally produced up to 3.4 mW per bimorph. This paper will discuss these results and present our initial analyses of the device using dimensional analysis and constitutive electromechanical modeling. The analysis suggests that an order-of-magnitude improvement in power generation from the current design is possible.

  10. Optimal Design of a Subsonic Submerged Inlet

    Science.gov (United States)

    Taskinoglu, Ezgi; Jovanovic, Vasilije; Elliott, Gregory; Knight, Doyle

    2003-11-01

    A multi-objective optimization study based on an epsilon-constraint method is conducted for the design optimization of a subsonic submerged air vehicle inlet. The multi-objective optimization problem is reformulated by minimizing one of the objectives and restricting the other objectives within user specified values. The figures of merits are the engine-face distortion and swirl that determines the inlet/engine compatibility. The distortion index is minimized while the feasible design space is determined by the swirl index. The design variables are the geometrical parameters defining the surface alteration. The design algorithm is driven by a gradient-based optimizer, and is constructed by integrating the optimizer with a solid modeller (Pro/Engineer), a mesh generator (Grid/Pro) and a flow solver (GASPex). The optimizer is CFSQP (C code for Feasible Sequential Quadratic Programming). Integration of the software packages is achieved by a Perl script. In order to verify the numerical results, an experimental setup for the same inlet geometry is prepared to run at the same flow conditions. The presentation will describe the numerical approach and summarize the results.

  11. Unsteady lubrication modeling of inlet zone in metal rolling processes

    Institute of Scientific and Technical Information of China (English)

    毛明智; 谭建平

    2002-01-01

    An unsteady lubrication model of inlet zone in metal rolling was established. The simulation computations show that for the variation amplitude of the inlet film thickness, the variation of the inlet angle contributes the largest, the surface mean speed contributes the second and the back tension stress the least. The higher the input frequency is, the smaller the amplitude output of the inlet film thickness will be. For a sinusoidal input, the inlet film thickness varies periodically but is not a sine wave because the system is not linear.

  12. F-15B ACTIVE with thrust vectoring nozzles on test stand

    Science.gov (United States)

    1995-01-01

    This November 13, 1995, photograph of the F-15 Advanced Controls Technology for Integrated Vehicles (ACTIVE) at NASA's Dryden Flight Research Center, Edwards, California, shows the thrust stand being used for ground testing of a new thrust-vectoring concept involving two new Pratt & Whitney nozzles that can turn up to 20 degrees in any direction. These nozzles give the aircraft thrust control in the pitch (up and down) and yaw (left and right) directions. This will reduce drag and increase fuel economy or range as compared with conventional aerodynamic controls, which increase the retarding forces (drag) acting upon the aircraft. These tests could lead to significant performance increases for military and commercial aircraft. The research program is the product of a collaborative effort by NASA, the Air Force's Wright Laboratory, Pratt & Whitney, and McDonnell Douglas Aerospace.

  13. Unstart coupling mechanism analysis of multiple-modules hypersonic inlet.

    Science.gov (United States)

    Hu, Jichao; Chang, Juntao; Wang, Lei; Cao, Shibin; Bao, Wen

    2013-01-01

    The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  14. Navier-Stokes predictions of multifunction nozzle flows

    Science.gov (United States)

    Wilmoth, Richard G.; Leavitt, Laurence D.

    1987-10-01

    A two-dimensional, Navier-Stokes code developed by Imlay based on the implicit, finite-volume method of MacCormack has been applied to the prediction of the flow fields and performance of several nonaxisymmetric, convergent-divergent nozzles with and without thrust vectoring. Comparisons of predictions with experiment show that the Navier-Stokes code can accurately predict both the flow fields and performance for nonaxisymmetric nozzles where the flow is predominantly two-dimensional and at nozzle pressure ratios at or above the design values. Discrepancies between predictions and experiment are noted at lower nozzle pressure ratios where separation typically occurs in portions of the nozzle. The overall trends versus parameters such as nozzle pressure ratio, flap angle, and vector angle were generally predicted correctly.

  15. Fluidized-bed calciner with combustion nozzle and shroud

    Science.gov (United States)

    Wielang, Joseph A.; Palmer, William B.; Kerr, William B.

    1977-01-01

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition.

  16. Experimental study of subsonic microjet escaping from a rectangular nozzle

    Science.gov (United States)

    Aniskin, V. M.; Maslov, A. A.; Mukhin, K. A.

    2016-10-01

    The first experiments on the subsonic laminar microjets escaping from the nozzles of rectangular shape are carried out. The nozzle size is 83.3x3823 microns. Reynolds number calculated by the nozzle height and the average flow velocity at the nozzle exit ranged from 58 to 154. The working gas was air at room temperature. The velocity decay and velocity fluctuations along the center line of the jet are determined. The fundamental difference between the laminar microjets characteristics and subsonic turbulent jets of macro size is shown. Based on measurements of velocity fluctuations it is shown the presence of laminar-turbulent transition in microjets and its location is determined.

  17. Heat and fluid flow properties of circular impinging jet with a low nozzle to plate spacing. Improvement by nothched nozzle; Nozzle heibankan kyori ga chiisai baai no enkei shototsu funryu no ryudo dennetsu tokusei. Kirikaki nozzle ni yoru kaizen kojo

    Energy Technology Data Exchange (ETDEWEB)

    Shakouchih, T. [Mie University, Mie (Japan). Faculty of Engineering; Matsumoto, A.; Watanabe, A.

    2000-10-25

    It is well known that as decreasing the nozzle to plate spacing considerably the heat transfer coefficient of circular impinging jet, which impinges to the plate normally, increases remarkably. At that time, the flow resistance of nozzle-plate system also increases rapidly. In this study, in order to reduce the flow resistance and to enhance the heat transfer coefficient of the circular impinging jet with a considerably low nozzle to plate spacing, a special nozzle with notches is proposed, and considerable improvement of the flow and heat transfer properties are shown. The mechanism of enhancement of the heat transfer properties is also discussed. (author)

  18. Flow separation in rocket nozzles under high altitude condition

    Science.gov (United States)

    Stark, R.; Génin, C.

    2017-01-01

    The knowledge of flow separation in rocket nozzles is crucial for rocket engine design and optimum performance. Typically, flow separation is studied under sea-level conditions. However, this disregards the change of the ambient density during ascent of a launcher. The ambient flow properties are an important factor concerning the design of altitude-adaptive rocket nozzles like the dual bell nozzle. For this reason an experimental study was carried out to study the influence of the ambient density on flow separation within conventional nozzles.

  19. Variable volume combustor with aerodynamic fuel flanges for nozzle mounting

    Energy Technology Data Exchange (ETDEWEB)

    McConnaughhay, Johnie Franklin; Keener, Christopher Paul; Johnson, Thomas Edward; Ostebee, Heath Michael

    2016-09-20

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and for providing the flow of fuel therethrough. The fuel injection system also may include a number of aerodynamic fuel flanges connecting the micro-mixer fuel nozzles and the support struts.

  20. Evaluation of nozzle shapes for an optical flow meter

    Science.gov (United States)

    Sheikholeslami, M. Z.; Patel, B. R.

    1992-05-01

    Numerical modeling is performed for turbulent flow in axisymmetric nozzles using Creare's computer program FLUENT/BFC. The primary objective of the project was to assist Spectron Development Laboratories in selecting an optimum nozzle shape for an optical flowmeter. The nozzle performance is evaluated for various length to diameter ratios, area contraction ratios, and Reynolds numbers. The computations have demonstrated that a cubic profile nozzle with length to diameter ratio of 1.6 and area contraction ratio of 6.2 can decrease the velocity profile non-uniformity from 15 percent at the entrance to 1 percent at the exit. The configuration is recommended for further investigation.

  1. Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature

    Science.gov (United States)

    Bui, Trong

    2010-01-01

    An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS aircraft. The current study also provided important information on proper modeling of the LaNCETS aircraft nozzle. The primary objective of the current CFD research effort was to support the LaNCETS flight research data analysis effort by studying the detailed nozzle exhaust jet plume s imperfect expansion effects on the sonic boom signature of a supersonic aircraft. Figure 1 illustrates the primary flow physics present in the interaction between the exhaust jet plume shock and the sonic boom coming off of an axisymmetric body in supersonic flight. The steeper tail shock from highly expanded jet plume reduces the dip of the sonic boom N-wave signature. A structured finite-volume compressible full Navier-Stokes CFD code was used in the current study. This approach is not limited by the simplifying assumptions inherent in previous sonic boom analysis efforts. Also, this study was the first known jet plume sonic boom CFD study in which the full viscous nozzle flow field was modeled, without

  2. Low Cost Carbon-Carbon Rocket Nozzle Development Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This development will provide an inexpensive vacuum nozzle manufacturing option for NOFBXTM monopropellant systems that are currently being developed under NASA SBIR...

  3. Long-Term Morphological Modeling of Barrier Island Tidal Inlets

    Directory of Open Access Journals (Sweden)

    Richard Styles

    2016-09-01

    Full Text Available The primary focus of this study is to apply a two-dimensional (2-D coupled flow-wave-sediment modeling system to simulate the development and growth of idealized barrier island tidal inlets. The idealized systems are drawn from nine U.S. coastal inlets representing Pacific Coast, Gulf Coast and Atlantic Coast geographical and climatological environments. A morphological factor is used to effectively model 100 years of inlet evolution and the resulting morphological state is gauged in terms of the driving hydrodynamic processes. Overall, the model performs within the range of established theoretically predicted inlet cross-sectional area. The model compares favorably to theoretical models of maximum inlet currents, which serve as a measure of inlet stability. Major morphological differences are linked to inlet geometry and tidal forcing. Narrower inlets develop channels that are more aligned with the inlet axis while wider inlets develop channels that appear as immature braided channel networks similar to tidal flats in regions with abundant sediment supply. Ebb shoals with strong tidal forcing extend further from shore and spread laterally, promoting multi-lobe development bisected by ebb shoal channels. Ebb shoals with moderate tidal forcing form crescent bars bracketing a single shore-normal channel. Longshore transport contributes to ebb shoal asymmetry and provides bed material to help maintain the sediment balance in the bay.

  4. Cold water inlet in solar tanks - valuation

    DEFF Research Database (Denmark)

    Andersen, Elsa

    1999-01-01

    The aim of the project is to make a proposal for how to value a storage tank with a poor design of the cold water inlet. Based on measurements and calculations a number of curves, which are valid for this valuation, are worked out. Based on a simple test with a uniform heated storage tank the ratio...... between the energy tapped in one storage volume and the energy content in the tank before the tapping is measured. Afterwards the mixing factor, corresponding to the measured ratio, can be determined. It is proposed that the mixing factor is taken into consideration when the governmental subsidy for SDHW...

  5. Marine Ice Atlas for Cook Inlet, Alaska

    Science.gov (United States)

    2007-11-02

    microwave/imager TDD thawing degree-day USACE U.S. Army Corps of Engineers USCB U.S. Census Bureau USCG U.S. Coast Guard USNO U.S. Naval Observatory WMO...large com- mercial fishing fleet based there. Homer, also a center for tourism , has a population of about 4,800. Marine facilities there include a deep...the importance of commercial navigation, fishing, and tourism access to remote sites around Cook Inlet, the practice continues today with even greater

  6. Low cost inlet filters for rainwater tanks

    OpenAIRE

    Martinson, Brett; Thomas, T.

    2005-01-01

    Inlet filters are a common method for enhancing water quality in rainwater harvesting systems. They range from cheap cloth or gravel filters to complex and expensive multi-stage systems. Field experience has shown, however that filters often suffer from a lack of maintenance so self-cleaning is an advantage. Filters can clean themselves by dividing the water stream into two components; the first and largest is the clean water passed to the tank, the second much smaller component can be used t...

  7. Hydraulics and Stability of Five Texas Inlets.

    Science.gov (United States)

    1981-01-01

    8217~~r 0.38 .. , q . P . I Pleasure Pier 7 Morgan’s Point 2 South Jetty 8 Railroad Causeway N 1. 3 Teuas City Dike 9 Chocolate Bayou A 4 Manna Reel 10 Son...Range and Level.............15 III HYDRAULICS AND STABILITY OF SPECIFIC INLETS...................... 15 1. Brazos River-Freeport Harbor Entrance...g acceleration of gravity K Keulegan repletion coefficient k wave number L channel length Le effective channel length n Manning’s coefficient P

  8. Study of nozzle deposit formation mechanism for direct injection gasoline engines; Chokufun gasoline engine yo nozzle no deposit seisei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, M.; Saito, A. [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsushita, S. [Toyota Motor Corp., Aichi (Japan); Shibata, H. [Nippon Soken, Inc., Tokyo (Japan); Niwa, Y. [Denso Corp., Aichi (Japan)

    1997-10-01

    Nozzles in fuel injectors for direct injection gasoline engines are exposed to high temperature combustion gases and soot. In such a rigorous environment, it is a fear that fuel flow rate changes in injectors by deposit formation on nozzles. Fundamental factors of nozzle deposit formation were investigated through injector bench tests and engine dynamometer tests. Deposit formation processes were observed by SEM through engine dynamometer tests. The investigation results reveal nozzle deposit formation mechanism and how to suppress the deposit. 4 refs., 8 figs., 3 tabs.

  9. Experimental investigation of the effects of length to diameter ratio and nozzle number on the performance of counter flow Ranque-Hilsch vortex tubes

    Science.gov (United States)

    Dincer, K.; Baskaya, S.; Uysal, B. Z.

    2008-01-01

    In this experimental study, performance of counter flow type Ranque-Hilsch vortex tubes (RHVT), with a length to diameter ratio of 10, 15 and 18, were investigated with 2, 4, 6 nozzles. The measure of performance was chosen as the difference between the temperatures of hot output stream and cold output stream. The performances of RHVTs were experimentally tested by making use of velocity and temperature measurements of the input and output streams. It was determined that the difference between the temperatures of these streams, changed between 9 and 56 K. When all the results were assessed, it was concluded that the best performance was obtained when the ratio of vortex tube’s length to the diameter was 15 and the nozzle number was at least four, and the inlet pressure was as high as possible. Desired performance could be obtained by controlling the rate of the hot output stream.

  10. Experimental investigation of the effects of length to diameter ratio and nozzle number on the performance of counter flow Ranque-Hilsch vortex tubes

    Energy Technology Data Exchange (ETDEWEB)

    Dincer, K. [Selcuk University, Department of Mechanical Engineering, Faculty of Engineering and Architecture, Konya (Turkey); Baskaya, S. [Gazi University, Department of Mechanical Engineering, Faculty of Engineering and Architecture, Maltepe, Ankara (Turkey); Uysal, B.Z. [Gazi University, Department of Chemical Engineering, Faculty of Engineering and Architecture, Maltepe, Ankara (Turkey)

    2008-01-15

    In this experimental study, performance of counter flow type Ranque-Hilsch vortex tubes (RHVT), with a length to diameter ratio of 10, 15 and 18, were investigated with 2, 4, 6 nozzles. The measure of performance was chosen as the difference between the temperatures of hot output stream and cold output stream. The performances of RHVTs were experimentally tested by making use of velocity and temperature measurements of the input and output streams. It was determined that the difference between the temperatures of these streams, changed between 9 and 56 K. When all the results were assessed, it was concluded that the best performance was obtained when the ratio of vortex tube's length to the diameter was 15 and the nozzle number was at least four, and the inlet pressure was as high as possible. Desired performance could be obtained by controlling the rate of the hot output stream. (orig.)

  11. Influence of Inlet / Shoal Complex on Adjacent Shorelines via Inlet Sink Method

    Science.gov (United States)

    2012-07-01

    placing dredged material onto adjacent beaches in moderate quantities (~200-500K cu yd) since the 1970 ’s (Dredging Information System (DIS...southward to Matanzas Inlet. Analysis of the ebb shoal volume change between surveys was made within a GIS framework using an area mask (Fig. 6

  12. CFD numerical simulation of Archimedes spiral inlet hydrocyclone

    Science.gov (United States)

    Zhang, L.; Wei, L.; Chang, B. H.; Xing, J. L.; Jia, K.

    2013-12-01

    For traditional linear type inlet, hydrocyclone has an unstable inner field, high turbulence intensity and low separation efficiency, this paper proposes an inlet mode that uses an Archimedes spiral hydrocyclone. A Mixture liquid-solid multiphase flow model combined with the kinetic theory of granular flow was used to simulate the high concentration water-sand-air three-phase flow in a hydrocyclone. We analyzed the pressure field, velocity field and turbulent kinetic energy and compared with traditional linear type inlet hydrocyclone inner field. The results show that Archimedes spiral inlet hydrocyclone's pressure field is evenly distributed. The Archimedes spiral inlet hydrocyclone can guide and accelerate the mixture flow and produce small forced vortex and less short circuit flow. The particles easily go to the outer vortex and are separated. The Archimedes spiral inlet hydrocyclone has effectively improved the stability of inner flow field and separation efficiency.

  13. Simulating radiative shocks in nozzle shock tubes

    Science.gov (United States)

    van der Holst, B.; Tóth, G.; Sokolov, I. V.; Daldorff, L. K. S.; Powell, K. G.; Drake, R. P.

    2012-06-01

    We use the recently developed Center for Radiative Shock Hydrodynamics (CRASH) code to numerically simulate laser-driven radiative shock experiments. These shocks are launched by an ablated beryllium disk and are driven down xenon-filled plastic tubes. The simulations are initialized by the two-dimensional version of the Lagrangian Hyades code which is used to evaluate the laser energy deposition during the first 1.1 ns. Later times are calculated with the CRASH code. CRASH solves for the multi-material hydrodynamics with separate electron and ion temperatures on an Eulerian block-adaptive-mesh and includes a multi-group flux-limited radiation diffusion and electron thermal heat conduction. The goal of the present paper is to demonstrate the capability to simulate radiative shocks of essentially three-dimensional experimental configurations, such as circular and elliptical nozzles. We show that the compound shock structure of the primary and wall shock is captured and verify that the shock properties are consistent with order-of-magnitude estimates. The synthetic radiographs produced can be used for comparison with future nozzle experiments at high-energy-density laser facilities.

  14. Magnetic Nozzle Simulation Studies for Electric Propulsion

    Science.gov (United States)

    Tarditi, Alfonso

    2010-11-01

    Electric Propulsion has recently re-gained interest as one of the key technologies to enable NASA's long-range space missions. Options are being considered also in the field of aneutronic fusion propulsion for high-power electric thrusters. To support these goals the study of the exhaust jet in a plasma thruster acquires a critical importance because the need of high-efficiency generation of thrust. A model of the plasma exhaust has been developed with the 3D magneto-fluid NIMROD code [1] to study the physics of the plasma detachment in correlation with experimentally relevant configurations. The simulations show the role of the plasma diamagnetism and of the magnetic reconnection process in the formation of a detached plasma. Furthermore, in direct fusion-propulsion concepts high-energy (MeV range) fusion products have to be efficiently converted into a slower and denser plasma jet (with specific impulse down to few 1000's seconds, for realistic missions in the Solar System). For this purpose, a two-stage conversion process is being modeled where high-energy ions are non-adiabatically injected and confined into a magnetic duct leading to the magnetic nozzle, transferring most of their energy into their gyro-motion and drifting at slower speed along with the plasma propellant. The propellant acquires then thermal energy that gets converted into the direction of thrust by the magnetic nozzle. [1] C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004).

  15. Analytical study of nozzle performance for nuclear thermal rockets

    Science.gov (United States)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    Nuclear propulsion has been identified as one of the key technologies needed for human exploration of the Moon and Mars. The Nuclear Thermal Rocket (NTR) uses a nuclear reactor to heat hydrogen to a high temperature followed by expansion through a conventional convergent-divergent nozzle. A parametric study of NTR nozzles was performed using the Rocket Engine Design Expert System (REDES) at the NASA Lewis Research Center. The REDES used the JANNAF standard rigorous methodology to determine nozzle performance over a range of chamber temperatures, chamber pressures, thrust levels, and different nozzle configurations. A design condition was set by fixing the propulsion system exit radius at five meters and throat radius was varied to achieve a target thrust level. An adiabatic wall was assumed for the nozzle, and its length was assumed to be 80 percent of a 15 degree cone. The results conclude that although the performance of the NTR, based on infinite reaction rates, looks promising at low chamber pressures, finite rate chemical reactions will cause the actual performance to be considerably lower. Parameters which have a major influence on the delivered specific impulse value include the chamber temperature and the chamber pressures in the high thrust domain. Other parameters, such as 2-D and boundary layer effects, kinetic rates, and number of nozzles, affect the deliverable performance of an NTR nozzle to a lesser degree. For a single nozzle, maximum performance of 930 seconds and 1030 seconds occur at chamber temperatures of 2700 and 3100 K, respectively.

  16. Rapid Fabrication Techniques for Liquid Rocket Channel Wall Nozzles

    Science.gov (United States)

    Gradl, Paul R.

    2016-01-01

    The functions of a regeneratively-cooled nozzle are to (1) expand combustion gases to increase exhaust gas velocity while, (2) maintaining adequate wall temperatures to prevent structural failure, and (3) transfer heat from the hot gases to the coolant fluid to promote injector performance and stability. Regeneratively-cooled nozzles are grouped into two categories: tube-wall nozzles and channel wall nozzles. A channel wall nozzle is designed with an internal liner containing a series of integral coolant channels that are closed out with an external jacket. Manifolds are attached at each end of the nozzle to distribute coolant to and away from the channels. A variety of manufacturing techniques have been explored for channel wall nozzles, including state of the art laser-welded closeouts and pressure-assisted braze closeouts. This paper discusses techniques that NASA MSFC is evaluating for rapid fabrication of channel wall nozzles that address liner fabrication, slotting techniques and liner closeout techniques. Techniques being evaluated for liner fabrication include large-scale additive manufacturing of freeform-deposition structures to create the liner blanks. Abrasive water jet milling is being evaluated for cutting the complex coolant channel geometries. Techniques being considered for rapid closeout of the slotted liners include freeform deposition, explosive bonding and Cold Spray. Each of these techniques, development work and results are discussed in further detail in this paper.

  17. The Effect of Nozzle Trailing Edge Thickness on Jet Noise

    Science.gov (United States)

    Henderson, Brenda; Kinzie, Kevin; Haskin, Henry

    2004-01-01

    The effect of nozzle trailing edge thickness on broadband acoustic radiation and the production of tones is investigated for coannular nozzles. Experiments were performed for a core nozzle trailing edge thickness between 0.38 mm and 3.17 mm. The on-set of discrete tones was found to be predominantly affected by the velocity ratio, the ratio of the fan velocity to the core velocity, although some dependency on trailing edge thickness was also noted. For a core nozzle trailing edge thickness greater than or equal to 0.89 mm, tones were produced for velocity ratios between 0.91 and 1.61. For a constant nozzle trailing edge thickness, the frequency varied almost linearly with the core velocity. The Strouhal number based on the core velocity changed with nozzle trailing edge thickness and varied between 0.16 and 0.2 for the core nozzles used in the experiments. Increases in broadband noise with increasing trailing edge thickness were observed for tone producing and non-tone producing conditions. A variable thickness trailing edge (crenellated) nozzle resulted in no tonal production and a reduction of the broadband trailing edge noise relative to that of the corresponding constant thickness trailing edge.

  18. Acoustic measurements of models of military style supersonic nozzle jets

    NARCIS (Netherlands)

    Kuo, C.W.; Veltin, J.; McLaughlin, D.K.

    2014-01-01

    Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. However, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and

  19. Instability of jet plume from an overexpanded nozzle

    Science.gov (United States)

    Papamoschou, Dimitri

    2005-11-01

    Our study involves the phenomenon of supersonic nozzle flow separation wherein a shock forms inside a convergent-divergent nozzle. Of particular interest is the instability of the jet plume exiting this type of nozzle. A rectangular apparatus of aspect ratio 3.57 and flexible walls enabled a parametric study of the mean and turbulent properties of the jet plume versus nozzle pressure ratio (from 1.2 to 2.0), exit-to-throat area ratio (from 1.0 to 1.8) and wall divergence angle at the nozzle exit (from 0 to 4 deg.) Time-resolved surveys of total pressure were obtained by means of a dynamic Pitot probe. The growth rate of the jet and the peak rms value of total pressure fluctuation near the nozzle exit increase several fold with area ratio. This trend becomes most pronounced for nozzle pressure ratio around 1.6. At fixed area ratio and nozzle pressure ratio, the wall divergence angle has little effect on the instability.

  20. Influence of different developer nozzle types on the photomask performance

    Science.gov (United States)

    Schmädicke, Cindy; Feicke, Axel; Herrmann, Mark; Bürgel, Christian

    2016-05-01

    The long-term development of electronics obliges increasingly tighter specifications for photomasks to meet the requirements of continuing miniaturization. We report on the influence of two different linear drive nozzle types A and B used for conducting the develop process on important mask properties, which comprise CD uniformity (CDU), loading behaviour, mean to target (MTT), iso-dense bias, line width roughness (LWR), linearity, resolution and defectivity. The results are presented for different resists, resist thicknesses and blank materials. First, the most important recipe parameters to ensure the best develop performance are defined and experimentally determined. Those critical factors are the nozzle scan speed over the mask, the develop time, the distance between nozzle and mask surface and the flow rate of the medium. It is demonstrated how these parameters can significantly affect the develop process performance. Dark loss experiments reveal that a more uniform resist removal takes place with the B kind of nozzle compared to that achieved with nozzle A. Based on the mask properties, the performances of two different nozzle types are compared. It is found that improvements with the B like nozzle can be achieved for CDU and loading. The presented nozzle type shows a promising approach to meet the requirements of future electronics.

  1. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  2. Acoustic measurements of models of military style supersonic nozzle jets

    NARCIS (Netherlands)

    Kuo, C.W.; Veltin, J.; McLaughlin, D.K.

    2014-01-01

    Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. However, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and t

  3. Long time durability tests of fabric inlet stratification pipes

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    The long time durability of seven different two layer fabric inlet stratification pipes for enhancing thermal stratification in hot water stores is investigated experimentally. Accelerated durability tests are carried out with the inlet stratification pipes both in a domestic hot water tank...... and that this destroys the capability of building up thermal stratification for the fabric inlet stratification pipe. The results also show that although dirt, algae etc. are deposited in the fabric pipes in the space heating tank, the capability of the fabric inlet stratifiers to build up thermal stratification...

  4. The Geometry of Selected U.S. Tidal Inlets.

    Science.gov (United States)

    1980-05-01

    Bodega Bay Inlet. Calif. 1931 NI C6GS S162 56 Humboldt Bay Inlet, Calif. 1859 NI CIGS 5710 57 Coos Bay Inlet. Oreg. 1885 NI USAE CB-I-18 58 Umpqua...Group 2 Group 3 Group 4 Group 5 Group 6 Outliers koriches Fripps Carolina Beach Lockwoods Folly Townsend Beaufort Hillsboro Stump St. Augustine Bodega ...Drakes Inlet, Calif. 1860 141 AlAN - -1 4-- * LtA94 LAND 0( -RAY 339 ft SECTON WDTHCHANNEL LENGTH 542. 626. Boo EGA BA 1931 C GS5162 BODEGA BAY 1931

  5. Hysteresis phenomenon of hypersonic inlet at high Mach number

    Science.gov (United States)

    Jiao, Xiaoliang; Chang, Juntao; Wang, Zhongqi; Yu, Daren

    2016-11-01

    When the hypersonic inlet works at a Mach number higher than the design value, the hypersonic inlet is started with a regular reflection of the external compression shock at the cowl, whereas a Mach reflection will result in the shock propagating forwards to cause a shock detachment at the cowl lip, which is called "local unstart of inlet". As there are two operation modes of hypersonic inlet at high Mach number, the mode transition may occur with the operation condition of hypersonic inlet changing. A cowl-angle-variation-induced hysteresis and a downstream-pressure-variation-induced hysteresis in the hypersonic inlet start↔local unstart transition are obtained by viscous numerical simulations in this paper. The interaction of the external compression shock and boundary layer on the cowl plays a key role in the hysteresis phenomenon. Affected by the transition of external compression shock reflection at the cowl and the transition between separated and attached flow on the cowl, a hysteresis exists in the hypersonic inlet start↔local unstart transition. The hysteresis makes the operation of a hypersonic inlet very difficult to control. In order to avoid hysteresis phenomenon and keep the hypersonic inlet operating in a started mode, the control route should never pass through the local unstarted boundary.

  6. Effects of Flow Parameters and Inlet Geometry on Cyclone Efficiency

    Institute of Scientific and Technical Information of China (English)

    赵兵涛

    2006-01-01

    A novel cyclone design, named converging symmetrical spiral inlet (CSSI) cyclone, is developed by improving the inlet geometry of conventional tangential single inlet (CTSI) cyclone for enhancing the physical performance of the cyclone.The collection efficiency of the CSSI cyclone is experimentally compared with the widely used CTSI cyclone. The results indicate that the CSSI cyclone provides higher collection efficiency by 5%~20% than that of the CTSI cyclone for a tested inlet velocity range of 11.99~23.85 m/s. In addition, the results of collection efficiency comparison between experimental data and theoretical model are also discussed.

  7. Inlet and airframe compatibility for a V/STOL fighter/attack aircraft with top-mounted inlets

    Science.gov (United States)

    Durston, D. A.; Smeltzer, D. B.

    1982-01-01

    Aerodynamic force and inlet pressure data are obtained for 9.5% force and pressure models of a V/STOL fighter/attack aircraft configuration with top mounted twin inlets. Data are presented from tests conducted in the Ames Unitary Wind Tunnels at Mach numbers of 0.6, 0.9, and 1.2 at angles of attack up to 27 deg. and angles of sideslip up to 12 deg. Trimmed aerodynamic characteristics and inlet performance are compared for three different leading edge extension (LEX) configurations. The effects of wing leading and trailing-edge flaps on the inlet are also determined. Maneuver perfromance is calculated form combined force and inlet pressure data. The largest of the three LEX sizes tested gives the best airplane maneuver performance. Wing flap deflections improved inlet recovery at all Mach numbers.

  8. Nozzle cooling of hot surfaces with various orientations

    Directory of Open Access Journals (Sweden)

    Horsky Jaroslav

    2012-04-01

    Full Text Available The aim of this research is an investigation of hot surface orientation influence on heat transfer during cooling by a nozzle. Two types of nozzles were used for the experiments (air-mist nozzle and hydraulic nozzle. A test plate was cooled in three positions – top, side and bottom position. The aim was to simulate a cooling situation in the secondary zone of a continuous casting machine. Temperature was measured in seven locations under the cooled surface by thermocouples. These data were used for an inverse heat conduction problem and then boundary conditions were computed. These boundary conditions are represented by surface temperature, heat transfer coefficient and heat flux. Results from an inverse calculation were compared in each position of thermocouples separately. The total cooling intensity was specified for all configurations of nozzles and test plate orientation. Results are summarised in a graphical and numerical format.

  9. Shape memory alloy actuated adaptive exhaust nozzle for jet engine

    Science.gov (United States)

    Song, Gangbing (Inventor); Ma, Ning (Inventor)

    2009-01-01

    The proposed adaptive exhaust nozzle features an innovative use of the shape memory alloy (SMA) actuators for actively control of the opening area of the exhaust nozzle for jet engines. The SMA actuators remotely control the opening area of the exhaust nozzle through a set of mechanism. An important advantage of using SMA actuators is the reduction of weight of the actuator system for variable area exhaust nozzle. Another advantage is that the SMA actuator can be activated using the heat from the exhaust and eliminate the need of other energy source. A prototype has been designed and fabricated. The functionality of the proposed SMA actuated adaptive exhaust nozzle is verified in the open-loop tests.

  10. Novel design for transparent high-pressure fuel injector nozzles

    Science.gov (United States)

    Falgout, Z.; Linne, M.

    2016-08-01

    The efficiency and emissions of internal combustion (IC) engines are closely tied to the formation of the combustible air-fuel mixture. Direct-injection engines have become more common due to their increased practical flexibility and efficiency, and sprays dominate mixture formation in these engines. Spray formation, or rather the transition from a cylindrical liquid jet to a field of isolated droplets, is not completely understood. However, it is known that nozzle orifice flow and cavitation have an important effect on the formation of fuel injector sprays, even if the exact details of this effect remain unknown. A number of studies in recent years have used injectors with optically transparent nozzles (OTN) to allow observation of the nozzle orifice flow. Our goal in this work is to design various OTN concepts that mimic the flow inside commercial injector nozzles, at realistic fuel pressures, and yet still allow access to the very near nozzle region of the spray so that interior flow structure can be correlated with primary breakup dynamics. This goal has not been achieved until now because interior structures can be very complex, and the most appropriate optical materials are brittle and easily fractured by realistic fuel pressures. An OTN design that achieves realistic injection pressures and grants visual access to the interior flow and spray formation will be explained in detail. The design uses an acrylic nozzle, which is ideal for imaging the interior flow. This nozzle is supported from the outside with sapphire clamps, which reduces tensile stresses in the nozzle and increases the nozzle's injection pressure capacity. An ensemble of nozzles were mechanically tested to prove this design concept.

  11. Inlet-engine matching for SCAR including application of a bicone variable geometry inlet. [Supersonic Cruise Aircraft Research

    Science.gov (United States)

    Wasserbauer, J. F.; Gerstenmaier, W. H.

    1978-01-01

    Airflow characteristics of variable cycle engines (VCE) designed for Mach 2.32 can have transonic airflow requirements as high as 1.6 times the cruise airflow. This is a formidable requirement for conventional, high performance, axisymmetric, translating centerbody mixed compression inlets. An alternate inlet is defined where the second cone of a two cone centerbody collapses to the initial cone angle to provide a large off-design airflow capability, and incorporates modest centerbody translation to minimize spillage drag. Estimates of transonic spillage drag are competitive with those of conventional translating centerbody inlets. The inlet's cruise performance exhibits very low bleed requirements with good recovery and high angle of attack capability.

  12. Usage of Connor Inlets to Eliminate Shrinkage

    Directory of Open Access Journals (Sweden)

    D. Fecko

    2012-09-01

    Full Text Available The demand for castings of high quality and sound work is nowadays very high. The production of sound castings without foundryerrors is the big issue in modern foundries. Foundry simulation software can do a lot to help improve the disposition of castings, gatingsystem and feeder system, and assure good filling and solidification conditions, and also produce sound casting without the need of the oldmethod of "try and error". One can easily change a lot of parameters for filling and solidification, and create the best proposal forproduction. Connor inlets have two functions. One is that it serves as an ingate, through which molten metal passes and comes into themould cavity. The second function is that it serves as a feeder and substitutes the metal contracted during solidification and cooling of the castings. It can also save quite a lot of metal in comparison to classic feeders.

  13. A Basic Study on the Ejection of ICI Nozzle under Severe Accidents

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jong Rae; Bae, Ji Hoon; Bang, Kwang Hyun [Korea Maritime and Ocean University, Busan (Korea, Republic of); Park, Jong Woong [Dongguk University, Gyeongju (Korea, Republic of)

    2016-05-15

    Nozzle injection should be blocked because it affect to the environment if its melting core exposes outside. The purpose of this study is to carry out the thermos mechanical analysis due to debris relocation under severe accidents and to predict the nozzle ejection calculated considering the contact between the nozzle and lower head, and the supports of pipe cables. As a result of analyzing process of severe accidents, there was melting reaction between nozzle and the lower head. In this situation, we might predict the non-uniform contact region of nozzle hole of lower head and nozzle outside, delaying ejection of nozzles. But after melting, the average remaining length of the nozzle was 120mm and the maximum vertical displacement of lower nozzle near the weld is 3.3mm so there would be no nozzle this model, because the cable supports restrains the vertical displacement of nozzle.

  14. Investigation of convergent-divergent nozzles applicable to reduced-power supersonic cruise aircraft

    Science.gov (United States)

    Berrier, B. L.; Re, R. J.

    1980-01-01

    An investigation was conducted of isolated convergent-divergent nozzles to determine the effect of several design parameters on nozzle performance. Tests were conducted using high pressure air for propulsion simulation at Mach numbers from 0.60 to 2.86 at an angle of attack of 0 deg and at nozzle pressure ratios from jet off to 46.0. Three power settings (dry, partial afterburning, and maximum afterburning), three nozzle lengths, and nozzle expansion ratios from 1.22 to 2.24 were investigated. In addition, the effects of nozzle throat radius and a cusp in the external boattail geometry were studied. The results of this study indicate that, for nozzles operating near design conditions, increasing nozzle length increases nozzle thrust-minus-drag performance. Nozzle throat radius and an external boattail cusp had negligible effects on nozzle drag or internal performance.

  15. Feedback mechanism for smart nozzles and nebulizers

    Science.gov (United States)

    Montaser, Akbar [Potomac, MD; Jorabchi, Kaveh [Arlington, VA; Kahen, Kaveh [Kleinburg, CA

    2009-01-27

    Nozzles and nebulizers able to produce aerosol with optimum and reproducible quality based on feedback information obtained using laser imaging techniques. Two laser-based imaging techniques based on particle image velocimetry (PTV) and optical patternation map and contrast size and velocity distributions for indirect and direct pneumatic nebulizations in plasma spectrometry. Two pulses from thin laser sheet with known time difference illuminate droplets flow field. Charge coupled device (CCL)) captures scattering of laser light from droplets, providing two instantaneous particle images. Pointwise cross-correlation of corresponding images yields two-dimensional velocity map of aerosol velocity field. For droplet size distribution studies, solution is doped with fluorescent dye and both laser induced florescence (LIF) and Mie scattering images are captured simultaneously by two CCDs with the same field of view. Ratio of LIF/Mie images provides relative droplet size information, then scaled by point calibration method via phase Doppler particle analyzer.

  16. 46 CFR 45.155 - Inlets and discharge piping: Valves.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Inlets and discharge piping: Valves. 45.155 Section 45... LINES Conditions of Assignment § 45.155 Inlets and discharge piping: Valves. (a) Except as provided in... visited by the crew. (e) Through-hull piping systems in machinery spaces may have valves with...

  17. Bedform evolution in a tidal inlet referred from wavelet analysis

    DEFF Research Database (Denmark)

    Fraccascia, Serena; Winter, Christian; Ernstsen, Verner Brandbyge;

    2011-01-01

    inlet and evaluate how they changed over consecutive years, when morphology was modified and bedforms migrated. High resolution bathymetric data from the Grådyb tidal inlet channel (Danish Wadden Sea) from seven years from 2002 to 2009 (not in 2004) were analyzed. Continuous wavelet transform of bed...

  18. Morphodynamics of tidal inlets in a tropical monsoon area

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Verhagen, H.J.; Wang, Z.B.

    2007-01-01

    Morphodynamics of a tidal inlet system on a micro-tidal coast in a tropical monsoon influenced region is modelled and discussed. Influences of river flow and wave climate on the inlet morphology are investigated with the aid of process-based state-of-the-art numerical models. Seasonal and episodic b

  19. 14 CFR 25.941 - Inlet, engine, and exhaust compatibility.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Inlet, engine, and exhaust compatibility. 25.941 Section 25.941 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF..., engine, and exhaust compatibility. For airplanes using variable inlet or exhaust system geometry, or...

  20. Serrating Nozzle Surfaces for Complete Transfer of Droplets

    Science.gov (United States)

    Kim, Chang-Jin " CJ" Yi, Uichong

    2010-01-01

    A method of ensuring the complete transfer of liquid droplets from nozzles in microfluidic devices to nearby surfaces involves relatively simple geometric modification of the nozzle surfaces. The method is especially applicable to nozzles in print heads and similar devices required to dispense liquid droplets having precise volumes. Examples of such devices include heads for soft printing of ink on paper and heads for depositing droplets of deoxyribonucleic acid (DNA) or protein solutions on glass plates to form microarrays of spots for analysis. The main purpose served by the present method is to ensure that droplets transferred from a nozzle have consistent volume, as needed to ensure accuracy in microarray analysis or consistent appearance of printed text and images. In soft printing, droplets having consistent volume are generated inside a print head, but in the absence of the present method, the consistency is lost in printing because after each printing action (in which a drop is ejected from a nozzle), a small residual volume of liquid remains attached to the nozzle. By providing for complete transfer of droplets (and thus eliminating residual liquid attached to the nozzle) the method ensures consistency of volume of transferred droplets. An additional benefit of elimination of residue is prevention of cross-contamination among different liquids printed through the same nozzle a major consideration in DNA microarray analysis. The method also accelerates the printing process by minimizing the need to clean a printing head to prevent cross-contamination. Soft printing involves a hydrophobic nozzle surface and a hydrophilic print surface. When the two surfaces are brought into proximity such that a droplet in the nozzle makes contact with the print surface, a substantial portion of the droplet becomes transferred to the print surface. Then as the nozzle and the print surface are pulled apart, the droplet is pulled apart and most of the droplet remains on the

  1. Elliptic nozzle aspect ratio effect on controlled jet propagation

    Science.gov (United States)

    Aravindh Kumar, S. M.; Rathakrishnan, Ethirajan

    2017-04-01

    The present study deals with the control of a Mach 2 elliptic jet from a convergent-divergent elliptic nozzle of aspect ratio 4 using tabs at the nozzle exit. The experiments were carried out for rectangular and triangular tabs of the same blockage, placed along the major and minor axes of the nozzle exit, at different levels of nozzle expansion. The triangular tabs along the minor axis promoted superior mixing compared to the other controlled jets and caused substantial core length reduction at all the nozzle pressure ratios studied. The rectangular tabs along the minor axis caused core length reduction at all pressure ratios, but the values were minimal compared to that of triangular tabs along the minor axis. For all the test conditions, the mixing promotion caused by tabs along the major axis was inferior to that of tabs along the minor axis. The waves present in the core of controlled jets were visualized using a shadowgraph. Comparison of the present results with the results of a controlled Mach 2 elliptic jet of aspect ratio 2 (Aravindh Kumar and Sathakrishnan 2016 J. Propulsion Power 32 121-33, Aravindh Kumar and Rathakrishnan 2016 J. Aerospace Eng. at press (doi:10.1177/0954410016652921)) show that for all levels of expansion, the mixing effectiveness of triangular tabs along the minor axis of an aspect ratio 4 nozzle is better than rectangular or triangular tabs along the minor axis of an aspect ratio 2 nozzle.

  2. Effect of inlet box on performance of axial flow fans

    Institute of Scientific and Technical Information of China (English)

    Jingyin LI; Hua TIAN; Xiaofang YUAN

    2008-01-01

    Numerical investigations on 3D flow fields in an axial flow fan with and without an inlet box have been extensively conducted, focusing on the variation of fan performance caused by the internal flow fields and the velocity evenness at the exit of the inlet box. It is interest-ing to find that although the inlet box is well designed in accordance with basic design principles, there is a flow separation region in it. Furthermore, this flow separation and the resulting uneven velocity distribution at the exit lead to some decrease in the efficiency and an increase in the total pressure rise of the fan. This research shows that the inlet box needs further improvement and such a check on the flow fields is of value for the design of inlet boxes.

  3. Application of LBB to a nozzle-pipe interface

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Y.J.; Sohn, G.H.; Kim, Y.J. [and others

    1997-04-01

    Typical LBB (Leak-Before-Break) analysis is performed for the highest stress location for each different type of material in the high energy pipe line. In most cases, the highest stress occurs at the nozzle and pipe interface location at the terminal end. The standard finite element analysis approach to calculate J-Integral values at the crack tip utilizes symmetry conditions when modeling near the nozzle as well as away from the nozzle region to minimize the model size and simplify the calculation of J-integral values at the crack tip. A factor of two is typically applied to the J-integral value to account for symmetric conditions. This simplified analysis can lead to conservative results especially for small diameter pipes where the asymmetry of the nozzle-pipe interface is ignored. The stiffness of the residual piping system and non-symmetries of geometry along with different material for the nozzle, safe end and pipe are usually omitted in current LBB methodology. In this paper, the effects of non-symmetries due to geometry and material at the pipe-nozzle interface are presented. Various LBB analyses are performed for a small diameter piping system to evaluate the effect a nozzle has on the J-integral calculation, crack opening area and crack stability. In addition, material differences between the nozzle and pipe are evaluated. Comparison is made between a pipe model and a nozzle-pipe interface model, and a LBB PED (Piping Evaluation Diagram) curve is developed to summarize the results for use by piping designers.

  4. Simple and Compact Nozzle Design for Laser Vaporization Sources

    CERN Document Server

    Kokish, M G; Odom, B C

    2015-01-01

    We have developed and implemented a compact transparent nozzle for use in laser vaporization sources. This nozzle eliminates the need for an ablation aperture, allowing for a more intense molecular beam. We use this nozzle to prepare a molecular beam of aluminum monohydride (AlH) suitable for ion trap loading of AlH$^+$ via photoionization in ultra-high vacuum. We demonstrate stable AlH production over hour time scales using a liquid ablation target. The long-term stability, low heat load and fast ion production rate of this source are well-suited to molecular ion experiments employing destructive state readout schemes requiring frequent trap reloading.

  5. Effusive Atomic Oven Nozzle Design Using a Microcapillary Array

    CERN Document Server

    Senaratne, Ruwan; Geiger, Zachary A; Fujiwara, Kurt M; Lebedev, Vyacheslav; Weld, David M

    2014-01-01

    We present a simple and inexpensive design for a multichannel effusive oven nozzle which provides improved atomic beam collimation and thus extended oven lifetimes. Using this design we demonstrate an atomic lithium source suitable for trapped-atom experiments. At a nozzle temperature of 525$^{\\circ}$C the total atomic beam flux directly after the nozzle is $1.2 \\times 10^{14}$ atoms per second with a peak beam intensity greater than $5.0 \\times 10^{16}$ atoms per second per steradian. This suggests an oven lifetime of several centuries of continuous operation.

  6. Probabilistic assessment of space nuclear propulsion system nozzle

    Science.gov (United States)

    Shah, Ashwin R.; Ball, Richard D.; Chamis, Christos C.

    1994-01-01

    In assessing the reliability of a space nuclear propulsion system (SNPS) nozzle, uncertainties associated with the following design parameters were considered: geometry, boundary conditions, material behavior, and thermal and pressure loads. A preliminary assessment of the reliability was performed using NESSUS (Numerical Evaluation of Stochastic Structures Under Stress), a finite-element computer code developed at the NASA Lewis Research Center. The sensitivity of the nozzle reliability to the uncertainties in the random variables was quantified. With respect to the effective stress, preliminary results showed that the nozzle spatial geometry uncertainties have the most significant effect at low probabilities whereas the inner wall temperature has the most significant effect at higher probabilities.

  7. Classification of tidal inlets along the Central east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.A.; Vikas, M.; Rao, S.; JayaKumar S.

    ) as long as the alongshore sediment bypasses the tidal inlet. Classification of coastal systems in a broader view is necessary for the management of tidal inlets. There are several methods to classify tidal inlets based on different perspectives namely geo...

  8. CO2 Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    Science.gov (United States)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. Computational Fluid Dynamic (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES). Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute (ACFM) were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the total oxygen consumption and CO2 production measured by additional gas analyzers at the air outlet from the suit. Real-time metabolic rate measurements were

  9. Carbon Dioxide Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    Science.gov (United States)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy, and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject, and physiological differences between subjects. Computational Fluid Dynamics (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit, and the Enhanced Mobility Advanced Crew Escape Suit. Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the CO2 production measured by an additional gas analyzer at the air outlet from the suit. Real-time metabolic rate measurements were used to adjust the treadmill workload to meet

  10. Study on Flow Field Characteristics of Nozzle Water Jet in Hydraulic cutting

    Science.gov (United States)

    Liao, Wen-tao; Deng, Xiao-yu

    2017-08-01

    Based on the theory of hydrodynamics, a mathematical model of nozzle water jet flow field in hydraulic cutting is established. By numerical simulation, the effects of nozzle convergence angle, nozzle outlet diameter and cylindrical section length on water jet flow impact is obtained, and the influence of three factors on the nozzle water jet flow field is analyzed. The optimal nozzle parameters are obtained by simulation as follows: convergence angle is 13 °, cylindrical section length is 8 mm and nozzle outlet diameter is 2 mm. Under this optimal nozzle parameters, hydraulic cutting has the best comprehensive effect.

  11. Design and Analyses of High Aspect Ratio Nozzles for Distributed Propulsion Acoustic Measurements

    Science.gov (United States)

    Dippold, Vance F., III

    2016-01-01

    A series of three convergent round-to-rectangular high-aspect ratio nozzles were designed for acoustics measurements. The nozzles have exit area aspect ratios of 8:1, 12:1, and 16:1. With septa inserts, these nozzles will mimic an array of distributed propulsion system nozzles, as found on hybrid wing-body aircraft concepts. Analyses were performed for the three nozzle designs and showed that the flow through the nozzles was free of separated flow and shocks. The exit flow was mostly uniform with the exception of a pair of vortices at each span-wise end of the nozzle.

  12. Performance influence in submersible pump with different diffuser inlet widths

    Directory of Open Access Journals (Sweden)

    Qingshun Wei

    2016-12-01

    Full Text Available The diffuser inlet width is a key geometric parameter that affects submersible pump performance. On the basis of diffuser characteristic curve analyses, diffusers with different inlet widths and the same impeller were equipped to construct a submersible pump model through the use of AutoCAD software. The performance curves of the submersible pump, with six diffuser inlet widths, were obtained using computational fluid dynamics method. Simultaneously, the simulation results were tested with the experimental method presented in this article. The results show that the optimum value of the inlet width (b3 = 50 mm is larger than the experience-based one. With an increase in the inlet width, the optimum operating point of a submersible pump offsets to a larger flow rate. When the guide blade inlet width is approximately 40–55 mm, the submersible pump efficiency is relatively high, approximately 75.9%–83.7% capacity, and the flow rate is approximately 105–135 m3/h. The numerical results of submersible pump performance are higher than those of the test results; however, their change trends have an acceptable agreement with each other. The practical significance is supplied by changing the inlet width of the diffuser to expand the scope of use.

  13. Unstart Coupling Mechanism Analysis of Multiple-Modules Hypersonic Inlet

    Directory of Open Access Journals (Sweden)

    Jichao Hu

    2013-01-01

    Full Text Available The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.

  14. Flow Simulation of Supersonic Inlet with Bypass Annular Duct

    Science.gov (United States)

    Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.

    2011-01-01

    A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.

  15. An evaluation of nozzle afterbody code - AR02P

    Science.gov (United States)

    Guyton, F. C.

    1986-07-01

    A project was undertaken to develop a computational fluid dynamics (CFD) code for use in nozzle afterbody analysis. Objectives were to create a three-dimensional code capable of calculating afterbody flows with accuracy quantitatively close to the Navier-Stokes solutions, but which would use significantly fewer computer resources. The resulting program coupled an inverse boundary-layer routine with an Euler code and incorporated a jet plume. Calculations were made for the axisymmetric AGARD 15-deg boattail afterbody with variations in nozzle pressure ratio for Mach numbers 0.6 and 0.9, and compared with experimental results. The code predicted drag changes with NPR which showed the proper variations, but the code did not provide the accuracy required for typical nozzle afterbody analysis. (NPR = Nozzle total pressure to free stream static pressure ratio.)

  16. Altitude Compensating Nozzle Transonic Performance Flight Demonstration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Altitude compensating nozzles continue to be of interest for use on future launch vehicle boosters and upper stages because of their higher mission average Isp and...

  17. Improvement of Flow Quality in NAL Chofu Mach 10 Nozzle

    Science.gov (United States)

    Lacey, John; Inoue, Yasutoshi; Higashida, Akio; Inoue, Manabu; Ishizaka, Kouichi; Korte, John J.

    2002-01-01

    As a result of CFD analysis and remachining of the nozzle, the flow quality of the Mach 10 Hypersonic Wind Tunnel at NAL Chofu, Japan was improved. The subsequent test results validated the CFD analytical predictions by NASA and MHL.

  18. Optimal Thrust Vectoring for an Annular Aerospike Nozzle Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recent success of an annular aerospike flight test by NASA Dryden has prompted keen interest in providing thrust vector capability to the annular aerospike nozzle...

  19. BOILING WATER REACTOR WITH FEED WATER INJECTION NOZZLES

    Science.gov (United States)

    Treshow, M.

    1963-04-30

    This patent covers the use of injection nozzles for pumping water into the lower ends of reactor fuel tubes in which water is converted directly to steam. Pumping water through fuel tubes of this type of boiling water reactor increases its power. The injection nozzles decrease the size of pump needed, because the pump handles only the water going through the nozzles, additional water being sucked into the tubes by the nozzles independently of the pump from the exterior body of water in which the fuel tubes are immersed. The resulting movement of exterior water along the tubes holds down steam formation, and thus maintains the moderator effectiveness, of the exterior body of water. (AEC)

  20. Flashback detection sensor for lean premix fuel nozzles

    Science.gov (United States)

    Thornton, Jimmy Dean; Richards, George Alan; Straub, Douglas L.; Liese, Eric Arnold; Trader, Jr., John Lee; Fasching, George Edward

    2002-08-06

    A sensor for detecting the flame occurring during a flashback condition in the fuel nozzle of a lean premix combustion system is presented. The sensor comprises an electrically isolated flashback detection electrode and a guard electrode, both of which generate electrical fields extending to the walls of the combustion chamber and to the walls of the fuel nozzle. The sensor is positioned on the fuel nozzle center body at a location proximate the entrance to the combustion chamber of the gas turbine combustion system. The sensor provides 360.degree. detection of a flashback inside the fuel nozzle, by detecting the current conducted by the flame within a time frame that will prevent damage to the gas turbine combustion system caused by the flashback condition.

  1. Design of a continuously variable Mach-number nozzle

    Institute of Scientific and Technical Information of China (English)

    郭善广; 王振国; 赵玉新

    2015-01-01

    A design method was developed to specify the profile of the continuously variable Mach-number nozzle for the supersonic wind tunnel. The controllable contour design technique was applied to obtaining the original nozzle profile, while other Mach- numbers were derived from the transformation of the original profile. A design scheme, covering a Mach-number range of 3.0nozzle. The computed results indicate that exit uniform flow is obtained with 1.19% of the maximal Mach-number deviation at the nozzle exit. The present design method achieves the continuously variable Mach-number flow during a wind tunnel running.

  2. Noise Characteristics of Overexpanded Jets from Convergent-Divergent Nozzles

    Science.gov (United States)

    Zaman, K. B. M. Q.

    2008-01-01

    A broadband noise component occurring in the overexpanded flow regime with convergent-divergent nozzles is identified. Relative to a convergent nozzle, at same pressure ratios, this excess noise can lead to a large increase in the overall sound pressure levels. Several features distinguish it from the more familiar broadband shock associated noise. Unlike the latter, it is observed even at shallow polar locations and there is no noticeable shift of the spectral content in frequency with observation angle. The amplitudes are found to be more pronounced with nozzles having larger half-angle of the divergent section. The noise apparently occurs when a shock resides within the divergent section of the nozzle and results from random unsteady motion of the shock.

  3. Improvement of Flow Quality in NAL Chofu Mach 10 Nozzle

    Science.gov (United States)

    Lacey, John; Inoue, Yasutoshi; Higashida, Akio; Inoue, Manabu; Ishizaka, Kouichi; Korte, John J.

    2002-01-01

    As a result of CFD analysis and remachining of the nozzle, the flow quality of the Mach 10 Hypersonic Wind Tunnel at NAL Chofu, Japan was improved. The subsequent test results validated the CFD analytical predictions by NASA and MHL.

  4. Inlet Guide Vane Wakes Including Rotor Effects

    Science.gov (United States)

    Johnston, R. T.; Fleeter, S.

    2001-02-01

    Fundamental experiments are described directed at the investigation of forcing functions generated by an inlet guide vane (IGV) row, including interactions with the downstream rotor, for application to turbomachine forced response design systems. The experiments are performed in a high-speed research fan facility comprised of an IGV row upstream of a rotor. IGV-rotor axial spacing is variable, with the IGV row able to be indexed circumferentially, thereby allowing measurements to be made across several IGV wakes. With an IGV relative Mach number of 0.29, measurements include the IGV wake pressure and velocity fields for three IGV-rotor axial spacings. The decay characteristics of the IGV wakes are compared to the Majjigi and Gliebe empirical correlations. After Fourier decomposition, a vortical-potential gust splitting analysis is implemented to determine the vortical and potential harmonic wake gust forcing functions both upstream and downstream of the rotor. Higher harmonics of the vortical gust component of the IGV wakes are found to decay at a uniform rate due to viscous diffusion.

  5. Is Cervical Inlet Patch Important Clinical Problem?

    Science.gov (United States)

    SAHIN, Gurol; ADAS, Gokhan; KOC, Bora; AKCAKAYA, Adem; DOGAN, Yasar; Goksel, Suha; Yalcin, Ozben

    2014-01-01

    AIM: In this study we aim to determine the frequency of Inlet Patch (IP) and its association to clinical symptoms and draw attention to be aware of this heterotopic gastric mucosa. METHODS: This study was a prospective case series that IP was detected in the upper gastrointestinal endoscopy. Patients with laringopharyngeal reflux symptoms underwent endoscopy between March 2009 and July 2012 in two different institutions. All the biopsies were obtained from if there is the IP lesion and antral or/and gastric mucosa. The data was prospectively evaluated. The prevalence was compared with those of patients that did not determine IP in the study period. RESULTS: 3907 upper gastrointestinal system endoscopy was performed while 123 patients consist of 51 male and 72 female was determined as IP. The prevalence of IP in patiens who underwent upper gastrointestinal endoscopy was 3.14% in our study. The majority of symptoms of those who had IP were laringopharyngeal reflux symptoms. Heterotopic gastric mucosa was fixed in 114 cases while 28 chronic inflammation, 9 esophagitis, 5 intestinal metaplasia, 4 glicogenic acanthosis were obtained as additional findings in pathological examinations. CONCLUSION: Heterotopic gastric mucosa in the proximal esophagus is a frequent finding if the endoscopist is aware of this entity. The importance of IP is the increasing number of cases of neoplastic transformation. Symptomatic patients should be treated and should be considered of the complications of heterotopic gastric mucosa. PMID:25018682

  6. Feasibility evaluation of the monolithic braided ablative nozzle

    Science.gov (United States)

    Director, Mark N.; McPherson, Douglass J., Sr.

    1992-02-01

    The feasibility of the monolithic braided ablative nozzle was evaluated as part of an independent research and development (IR&D) program complementary to the National Aeronautics and Space Administration/Marshall Space Flight Center (NASA/MSFC) Low-Cost, High-Reliability Case, Insulation and Nozzle for Large Solid Rocket Motors (LOCCIN) Program. The monolithic braided ablative nozzle is a new concept that utilizes a continuous, ablative, monolithic flame surface that extends from the nozzle entrance, through the throat, to the exit plane. The flame surface is fabricated using a Through-the-Thickness braided carbon-fiber preform, which is impregnated with a phenolic or phenolic-like resin. During operation, the braided-carbon fiber/resin material ablates, leaving the structural backside at temperatures which are sufficiently low to preclude the need for any additional insulative materials. The monolithic braided nozzle derives its potential for low life cycle cost through the use of automated processing, one-component fabrication, low material scrap, low process scrap, inexpensive raw materials, and simplified case attachment. It also has the potential for high reliability because its construction prevents delamination, has no nozzle bondlines or leak paths along the flame surface, is amenable to simplified analysis, and is readily inspectable. In addition, the braided construction has inherent toughness and is damage-tolerant. Two static-firing tests were conducted using subscale, 1.8 - 2.0-inch throat diameter, hardware. Tests were approximately 15 seconds in duration, using a conventional 18 percent aluminum/ammonium perchlorate propellant. The first of these tests evaluated the braided ablative as an integral backside insulator and exit cone; the second test evaluated the monolithic braided ablative as an integral entrance/throat/exit cone nozzle. Both tests met their objectives. Radial ablation rates at the throat were as predicted, approximately 0.017 in

  7. Simulation and Experimental Study on Cavitating Water Jet Nozzle

    Science.gov (United States)

    Zhou, Wei; He, Kai; Cai, Jiannan; Hu, Shaojie; Li, Jiuhua; Du, Ruxu

    2017-01-01

    Cavitating water jet technology is a new kind of water jet technology with many advantages, such as energy-saving, efficient, environmentally-friendly and so on. Based on the numerical simulation and experimental verification in this paper, the research on cavitating nozzle has been carried out, which includes comparison of the cleaning ability of the cavitating jet and the ordinary jet, and comparison of cavitation effects of different structures of cavitating nozzles.

  8. Influences of Geometric Parameters upon Nozzle Performances in Scramjets

    Institute of Scientific and Technical Information of China (English)

    Li Jianping; Song Wenyan; Xing Ying; Luo Feiteng

    2008-01-01

    This article investigates and presents the influences of geomea'ic parameters of a scramjet exerting upon its nozzle performances. These parameters include divergent angles, total lengths, height ratios, cowl lengths, and cowl angles. The flow field within the scramjet nozzle is simulated numerically by using the CFD software--FLUENT in association with coupled implicit solver and an RNG k-ε tur-bulence model.

  9. Jet-Engine Exhaust Nozzle With Thrust-Directing Flaps

    Science.gov (United States)

    Wing, David J.

    1996-01-01

    Convergent/divergent jet-engine exhaust nozzle has cruciform divergent passage containing flaps that move to deflect flow of exhaust in either or both planes perpendicular to main fore-and-aft axis of undeflected flow. Prototype of thrust-vector-control nozzles installed in advanced, high-performance airplanes to provide large pitching (usually, vertical) and yawing (usually, horizontal) attitude-control forces independent of attitude-control forces produced by usual aerodynamic control surfaces.

  10. Should we attempt global (inlet engine airframe) control design?

    Science.gov (United States)

    Carlin, C. M.

    1980-01-01

    The feasibility of multivariable design of the entire airplane control system is briefly addressed. An intermediate step in that direction is to design a control for an inlet engine augmentor system by using multivariable techniques. The supersonic cruise large scale inlet research program is described which will provide an opportunity to develop, integrate, and wind tunnel test a control for a mixed compression inlet and variable cycle engine. The integrated propulsion airframe control program is also discussed which will introduce the problem of implementing MVC within a distributed processing avionics architecture, requiring real time decomposition of the global design into independent modules in response to hardware communication failures.

  11. Conceptual Design of a Variable Air Inlet, JAS 39 Gripen

    OpenAIRE

    Rosén, Malin; Boström, Andreas

    2015-01-01

    The JAS 39 Gripen currently has a static air inlet designed for cooling the engine bay. This inlet has been developed over the years and has consisted of several different solutions. In this master’s thesis an investigation of past and current designs has been conducted in order to develop new concepts with a variable solution. Since the static inlet is designed for a worst case scenario, long duration of flight at low altitudes and high atmospheric temperatures, the cooling produced is not a...

  12. Variable geometry inlet design for scram jet engine

    Science.gov (United States)

    Guinan, Daniel P. (Inventor); Drake, Alan (Inventor); Andreadis, Dean (Inventor); Beckel, Stephen A. (Inventor)

    2005-01-01

    The present invention relates to an improved variable geometry inlet for a scram jet engine having at least one combustor module. The variable geometry inlet comprises each combustor module having two sidewalls. Each of the sidewalls has a central portion with a thickness and a tapered profile forward of the central portion. The tapered profile terminates in a sharp leading edge. The variable geometry inlet further comprises each module having a lower wall and a movable cowl flap positioned forward of the lower wall. The movable cowl flap has a leading edge and the leading edges of the sidewalls intersect the leading edge of the cowl flap.

  13. Simultaneous mass detection for direct inlet mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, R.L.

    1979-05-01

    The evolution of analytical techniques for application in trace analysis has led to interest in practical methods for real-time monitoring. Direct inlet mass spectrometry (DIMS) has been the subject of considerable activity in recent years. A DIMS instrument is described which consists of an inlet system designed to permit particles entrained in the inlet air stream to strike a hot, oxidized rhenium filament which serves as a surface ionization source. A mass analyzer and detection system then permits identification of the elemental composition of particulates which strike the filament.

  14. Nozzle Mounting Method Optimization Based on Robot Kinematic Analysis

    Science.gov (United States)

    Chen, Chaoyue; Liao, Hanlin; Montavon, Ghislain; Deng, Sihao

    2016-08-01

    Nowadays, the application of industrial robots in thermal spray is gaining more and more importance. A desired coating quality depends on factors such as a balanced robot performance, a uniform scanning trajectory and stable parameters (e.g. nozzle speed, scanning step, spray angle, standoff distance). These factors also affect the mass and heat transfer as well as the coating formation. Thus, the kinematic optimization of all these aspects plays a key role in order to obtain an optimal coating quality. In this study, the robot performance was optimized from the aspect of nozzle mounting on the robot. An optimized nozzle mounting for a type F4 nozzle was designed, based on the conventional mounting method from the point of view of robot kinematics validated on a virtual robot. Robot kinematic parameters were obtained from the simulation by offline programming software and analyzed by statistical methods. The energy consumptions of different nozzle mounting methods were also compared. The results showed that it was possible to reasonably assign the amount of robot motion to each axis during the process, so achieving a constant nozzle speed. Thus, it is possible optimize robot performance and to economize robot energy.

  15. Effect of Tabs on a Rectangular Nozzle Studied

    Science.gov (United States)

    2005-01-01

    In a continuing research program, jets from nozzles of different geometries are being investigated with the aim of increasing mixing and spreading in those flows. Flow fields from nozzles with elliptic, rectangular, and other more complex cross-sectional shapes are being studied in comparison to circular nozzles over a wide Mach number range. As noted by previous researchers, noncircular jets usually spread faster than circular jets. Another technique being investigated to increase jet spreading even further for a given nozzle is the use of "tabs" to generate vortices. A typical tab is a triangular-shaped protrusion placed at the nozzle exit, with the base of the triangle touching the nozzle wall and the apex leaning downstream at 45 to the stream direction. This geometry was determined by a parametric study to produce the optimum effect for a given area blockage. The tabs can increase jet spreading significantly. The underlying mechanism traces to a pair of counter-rotating streamwise vortices originating from each tab. These vortex pairs persist in the flow; and with the appropriate number and strength, they can increase spreading.

  16. Fluidic Control of Nozzle Flow: Some Performance Measurements

    Science.gov (United States)

    Federspiel, John; Bangert, Linda; Wing, David; Hawkes, Tim

    1995-01-01

    Results are presented of an experimental program that investigated the use of a secondary air stream to control the amount of flow through a convergent-divergent nozzle. These static tests utilized high pressure, ambient temperature air that was injected at the throat of the nozzle through an annular slot. Multiple injection slot sizes and injection angles were tested. The introduction of secondary flow was made in an opposing direction to the primary flow and the resulting flow field caused the primary stream to react as though the physical throat size had been reduced. The percentage reduction in primary flow rate was generally about twice the injected flow rate. The most effective throttling was achieved by injecting through the smallest slot in an orientation most nearly opposed to the approaching primary flow. Thrust edliciency, as measured by changes in nozzle thrust coefficient, was highest at high nozzle pressure ratios, NPR. The static test results agreed with predictions obtained prior from PABSD, a fully viscous computational fluid dynamics program. Since use of such an injection system on gas turbine engine exhaust nozzles would be primarily at high NPRs, it was concluded that fluidic control holds promise for reducing nozzle weight and complexity on future systems.

  17. Simulating radiative shocks in nozzle shock tubes

    CERN Document Server

    van der Holst, B; Sokolov, I V; Daldorff, L K S; Powell, K G; Drake, R P

    2011-01-01

    We use the recently developed Center for Radiative Shock Hydrodynamics (CRASH) code to numerically simulate laser-driven radiative shock experiments. These shocks are launched by an ablated beryllium disk and are driven down xenon-filled plastic tubes. The simulations are initialized by the two-dimensional version of the Lagrangian Hyades code which is used to evaluate the laser energy deposition during the first 1.1ns. The later times are calculated with the CRASH code. This code solves for the multi-material hydrodynamics with separate electron and ion temperatures on an Eulerian block-adaptive-mesh and includes a multi-group flux-limited radiation diffusion and electron thermal heat conduction. The goal of the present paper is to demonstrate the capability to simulate radiative shocks of essentially three-dimensional experimental configurations, such as circular and elliptical nozzles. We show that the compound shock structure of the primary and wall shock is captured and verify that the shock properties a...

  18. Particle Streak Velocimetry of Supersonic Nozzle Flows

    Science.gov (United States)

    Willits, J. D.; Pourpoint, T. L.

    2016-01-01

    A novel velocimetry technique to probe the exhaust flow of a laboratory scale combustor is being developed. The technique combines the advantages of standard particle velocimetry techniques and the ultra-fast imaging capabilities of a streak camera to probe high speed flows near continuously with improved spatial and velocity resolution. This "Particle Streak Velocimetry" technique tracks laser illuminated seed particles at up to 236 picosecond temporal resolution allowing time-resolved measurement of one-dimensional flows exceeding 2000 m/s as are found in rocket nozzles and many other applications. Developmental tests with cold nitrogen have been performed to validate and troubleshoot the technique with supersonic flows of much lower velocity and without background noise due to combusting flow. Flow velocities on the order of 500 m/s have been probed with titanium dioxide particles and a continuous-wave laser diode. Single frame images containing multiple streaks are analyzed to find the average slope of all incident particles corresponding to the centerline axial flow velocity. Long term objectives for these tests are correlation of specific impulse to theoretical combustion predictions and direct comparisons between candidate green fuels and the industry standard, monomethylhydrazine, each tested under identical conditions.

  19. Studies of the acoustic transmission characteristics of coaxial nozzles with inverted velocity profiles: Comprehensive data report. [nozzle transfer functions

    Science.gov (United States)

    Dean, P. D.; Salikuddin, M.; Ahuja, K. K.; Plumblee, H. E.; Mungur, P.

    1979-01-01

    The efficiency of internal noise radiation through a coannular exhaust nozzle with an inverted velocity profile was studied. A preliminary investigation was first undertaken (1) to define the test parameters which influence the internal noise radiation; (2) to develop a test methodology which could realistically be used to examine the effects of the test parameters; and (3) to validate this methodology. The result was the choice of an acoustic impulse as the internal noise source in the jet nozzles. Noise transmission characteristics of a coannular nozzle system were then investigated. In particular, the effects of fan convergence angle, core extension length to annulus height ratio and flow Mach numbers and temperatures were studied. Relevant spectral data only is presented in the form of normalized nozzle transfer function versus nondimensional frequency.

  20. An Alternative Ice Protection System for Turbine Engine Inlets Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal presents a dual approach to the development and certification of an alternative system for ice protection of turbine engine inlets. It combines a new...

  1. Piping Plover (Charadrius ntelodus) monitoring at Oregon Inlet, North Carolina

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report recommends a plan of monitoring Piping Plovers adjacent to Oregon Inlet relative to activities associated with the construction of a new bridge across...

  2. Cook Inlet and Kenai Peninsula, Alaska ESI: FISHL (Fish Lines)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for anadromous fish streams in Cook Inlet and Kenai Peninsula, Alaska. Vector lines in this data set represent...

  3. PIE Nacelle Flow Analysis and TCA Inlet Flow Quality Assessment

    Science.gov (United States)

    Shieh, C. F.; Arslan, Alan; Sundaran, P.; Kim, Suk; Won, Mark J.

    1999-01-01

    This presentation includes three topics: (1) Analysis of isolated boattail drag; (2) Computation of Technology Concept Airplane (TCA)-installed nacelle effects on aerodynamic performance; and (3) Assessment of TCA inlet flow quality.

  4. Cook Inlet and Kenai Peninsula, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for herring spawning areas in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent...

  5. Cook Inlet and Kenai Peninsula, Alaska ESI: INDEX (Index Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing the boundaries used in the creation of the Environmental Sensitivity Index (ESI) for Cook Inlet and Kenai...

  6. Cook Inlet and Kenai Peninsula, Alaska ESI: NESTS (Nest Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  7. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  8. Cook Inlet and Kenai Peninsula, Alaska ESI: INVERT (Invertebrate Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for razor clams in Cook Inlet and Kenai Peninsula, Alaska. Vector polygons in this data set represent locations of...

  9. Cook Inlet and Kenai Peninsula, Alaska ESI: VOLCANOS (Volcano Points)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains the locations of volcanos in Cook Inlet and Kenai Peninsula, Alaska. Vector points in the data set represent the location of the volcanos....

  10. Modelling the Evaporation Rate in an Impingement Jet Dryer with Multiple Nozzles

    Directory of Open Access Journals (Sweden)

    Anna-Lena Ljung

    2017-01-01

    Full Text Available Impinging jets are often used in industry to dry, cool, or heat items. In this work, a two-dimensional Computational Fluid Dynamics model is created to model an impingement jet dryer with a total of 9 pairs of nozzles that dries sheets of metal. Different methods to model the evaporation rate are studied, as well as the influence of recirculating the outlet air. For the studied conditions, the simulations show that the difference in evaporation rate between single- and two-component treatment of moist air is only around 5%, hence indicating that drying can be predicted with a simplified model where vapor is included as a nonreacting scalar. Furthermore, the humidity of the inlet air, as determined from the degree of recirculating outlet air, has a strong effect on the water evaporation rate. Results show that the metal sheet is dry at the exit if 85% of the air is recirculated, while approximately only 60% of the water has evaporated at a recirculation of 92,5%.

  11. A multiobjective shape optimization study for a subsonic submerged inlet

    Science.gov (United States)

    Taskinoglu, Ezgi S.

    The purpose of the present work is to summarize the findings of a multiobjective shape optimization study conducted for a subsonic submerged air vehicle inlet. The objective functions of the optimization problem are distortion and swirl indices defined by the distribution of flow parameters over the exit cross-section of the inlet. The geometry alteration is performed by placing a protrusion in the shape of a fin on the baseline inlet surface. Thus, the design variables of the optimization problem are chosen to be the geometrical parameters defining the fin protrusion; namely fin height, length and incidence angle. The Trade Off (also known as epsilon-constraint) method is employed for finding the Pareto optimal set formed by the nondominated solutions of the feasible design space. Since the flow domain solution is required for every step along the line search, an automated optimization loop is constructed by integrating the optimizer with a surface modeler, a mesh generator and a flow solver through which the flow parameters over the compressor face are computed. In addition, the trade study for fin protrusion, the analyses and the comparison of the baseline and Pareto optimal solutions are presented and observations concerning grid resolution and convergence behaviour are discussed. The results display an irregular and discontinuous Pareto optimal set. Optimum inlet designs are scattered in two regions from which one representative inlet design is chosen and analyzed. As a result, it is concluded that an inlet designer has two options within the framework of this optimization study: an inlet design with high swirl but low distortion or an inlet design with low swirl but higher distortion.

  12. Study on Characteristics of Different Types of Nozzles for Coal-Water Slurry Atomization

    Institute of Scientific and Technical Information of China (English)

    Kun Yuan; Lifang Chen; Chengkang Wu

    2001-01-01

    Three types of nozzles: a low-pressure multistage nozzle, an effervescent nozzle and a newly developed internal mixing air-blast nozzle, for atomization of Coal-Water Slurry (CWS) were investigated. Influence of CWS properties including surface tension and apparent viscosity on atomization was studied. Comparisons among the nozzles were carried out in terms of spray droplet mean diameter and fuel output. Versatility of each nozzle was investigated and atomization mechanism of each nozzle was analyzed as well. The results showed that the newly developed internal-mixing air-blast nozzle has high fuel output and small mean droplet size in the spray, but the multistage nozzle has high versatility for handling of low quality CWS.

  13. Parametric study of single expansion ramp nozzles at subsonic/transonic speeds

    Science.gov (United States)

    Capone, F. J.; Re, R. J.; Bare, E. A.; Maclean, M. K.

    1987-01-01

    The Langley Research Center has conducted a parametric investigation to determine the aeropropulsive characteristics of single expansion ramp nozzles (SERN). The SERN is a nonaxisymmetric, variable-area, internal/external expansion exhaust nozzle. Internal nozzle parameters that were varied included upper ramp length, ramp chordal angle, lower flap length, flap angle and the axial and vertical locations of nozzle throat. Convergent-divergent and convergent nozzles were included in this investigation which was conducted in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.6 to 1.2 and at nozzle pressure ratios up to 12.0.

  14. Influence of spray nozzle shape upon atomization process

    Science.gov (United States)

    Beniuga, Marius; Mihai, Ioan

    2016-12-01

    The atomization process is affected by a number of operating parameters (pressure, viscosity, temperature, etc.) [1-6] and the adopted constructive solution. In this article are compared parameters of atomized liquid jet with two nozzles that have different lifespan, one being new and the other one out. The last statement shows that the second nozzle was monitored as time of operation on the one hand and on the other hand, two dimensional nozzles have been analyzed using laser profilometry. To compare the experimental parameters was carried an experimental stand to change the period and pulse width in injecting liquid through two nozzles. Atomized liquid jets were photographed and filmed quickly. Images obtained were analyzed using a Matlab code that allowed to determine a number of parameters that characterize an atomized jet. Knowing the conditions and operating parameters of atomized jet, will establish a new wastewater nozzle block of parameter values that can be implemented in controller that provides dosing of the liquid injected. Experimental measurements to observe the myriad forms of atomized droplets to a wide range of operating conditions, realized using the electronic control module.

  15. General Investigation of Tidal Inlets: Stability of Selected United States Tidal Inlets

    Science.gov (United States)

    1991-09-01

    to determine the relationships that exist among the geometric and dynamic characterisa tics and the e n’. -onmen fac tocs that control these...73 5 50 Siletz, OR 7-39 to 2-76 4 51 Netarts, OR 7-53 to 7-73 4 Report Organizacion 8. Previous research on tidal inlet stability is summarized in Part...Relatinsh-i ps Among Time Variar.t Cha neteri tics Channel Indices R SC LC T W:L R 1 3 3 5 SC 0 3 0 3 LC 0 1 9 2 T 4 6 3 8 W: R 1 6 1 4 SC 0 1 2 3 LC 0 1 7 4

  16. Off-Design Performance of a Streamline-Traced, External-Compression Supersonic Inlet

    Science.gov (United States)

    Slater, John W.

    2017-01-01

    A computational study was performed to explore the aerodynamic performance of a streamline-traced, external-compression inlet designed for Mach 1.664 at off-design conditions of freestream Mach number, angle-of-attack, and angle-of-sideslip. Serious degradation of the inlet performance occurred for negative angles-of-attack and angles-of-sideslip greater than 3 degrees. At low subsonic speeds, the swept leading edges of the inlet created a pair of vortices that propagated to the engine face. Increasing the bluntness of the cowl lip showed no real improvement in the inlet performance at the low speeds, but did improve the inlet performance at the design conditions. Reducing the inlet flow rate improved the inlet performance, but at the likely expense of reduced thrust of the propulsion system. Deforming the cowl lip for low-speed operation of the inlet increased the inlet capture area and improved the inlet performance.

  17. Organics Verification Study for Sinclair and Dyes Inlets, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, Nancy P.; Brandenberger, Jill M.; Niewolny, Laurie A.; Johnston, Robert K.

    2006-09-28

    Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. Because significant cleanup and source control activities have been conducted in the inlets since the data supporting the 1998 303(d) listings were collected, two verification studies were performed to address the 303(d) segments that were listed for metal and organic contaminants in marine sediment. The Metals Verification Study (MVS) was conducted in 2003; the final report, Metals Verification Study for Sinclair and Dyes Inlets, Washington, was published in March 2004 (Kohn et al. 2004). This report describes the Organics Verification Study that was conducted in 2005. The study approach was similar to the MVS in that many surface sediment samples were screened for the major classes of organic contaminants, and then the screening results and other available data were used to select a subset of samples for quantitative chemical analysis. Because the MVS was designed to obtain representative data on concentrations of contaminants in surface sediment throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, aliquots of the 160 MVS sediment samples were used in the analysis for the Organics Verification Study. However, unlike metals screening methods, organics screening methods are not specific to individual organic compounds, and are not available for some target organics. Therefore, only the quantitative analytical results were used in the organics verification evaluation. The results of the Organics Verification Study showed that sediment quality outside of Sinclair Inlet is unlikely to be impaired because of organic contaminants. Similar to the results for metals, in Sinclair Inlet, the distribution of residual organic contaminants is generally limited to nearshore areas already within the

  18. Application of LES in the study of inlet flow field in marine gas turbine

    Institute of Scientific and Technical Information of China (English)

    SHI Bao-long; SUN Hai-ou; SUN Tao; HU Yan-yong

    2005-01-01

    The structure and aerodynamics performance of gas turbine inlet system is an important part of technology of gas turbine installed on naval vessels. The design and numerical simulations of gas turbine inlet system are conducted and reliable foundation for design and manufacture of marine gas turbine inlet system of high performance is provided. Numerical simulations and experiments of two inlet system models of gas turbine are conducted with satisfactory results and are of significance to the actual application of the inlet system.

  19. Development of explosive welding procedures to fabricate channeled nozzle structures

    Science.gov (United States)

    Pattee, H. E.; Linse, V. D.

    1976-01-01

    Research was conducted to demonstrate the feasibility of fabricating a large contoured structure with complex internal channeling by explosive welding procedures. Structures or nozzles of this nature for wind tunnel applications were designed. Such nozzles vary widely in their complexity. However, in their simplest form, they consist of a grooved base section to which a cover sheet is attached to form a series of internal cooling passages. The cover sheet attachment can be accomplished in various ways: fusion welding, brazing, and diffusion welding. The cover sheet has also been electroformed in place. Of these fabrication methods, brazing has proved most successful in producing nozzles with complex contoured surfaces and a multiplicity of internal channels.

  20. Temperature Histories in Ceramic-Insulated Heat-Sink Nozzle

    Science.gov (United States)

    Ciepluch, Carl C.

    1960-01-01

    Temperature histories were calculated for a composite nozzle wall by a simplified numerical integration calculation procedure. These calculations indicated that there is a unique ratio of insulation and metal heat-sink thickness that will minimize total wall thickness for a given operating condition and required running time. The optimum insulation and metal thickness will vary throughout the nozzle as a result of the variation in heat-transfer rate. The use of low chamber pressure results in a significant increase in the maximum running time of a given weight nozzle. Experimentally measured wall temperatures were lower than those calculated. This was due in part to the assumption of one-dimensional or slab heat flow in the calculation procedure.

  1. Aeroelastic stability analysis of flexible overexpanded rocket nozzle

    Science.gov (United States)

    Bekka, N.; Sellam, M.; Chpoun, A.

    2016-07-01

    The aim of this paper is to present a new aeroelastic stability model taking into account the viscous effects for a supersonic nozzle flow in overexpanded regimes. This model is inspired by the Pekkari model which was developed initially for perfect fluid flow. The new model called the "Modified Pekkari Model" (MPM) considers a more realistic wall pressure profile for the case of a free shock separation inside the supersonic nozzle using the free interaction theory of Chapman. To reach this objective, a code for structure computation coupled with aerodynamic excitation effects is developed that allows the analysis of aeroelastic stability for the overexpanded nozzles. The main results are presented in a comparative manner using existing models (Pekkari model and its extended version) and the modified Pekkari model developed in this work.

  2. The modelling of an SF6 arc in a supersonic nozzle: II. Current zero behaviour of the nozzle arc

    Science.gov (United States)

    Zhang, Q.; Liu, J.; Yan, J. D.; Fang, M. T. C.

    2016-08-01

    The present work (part II) forms the second part of an investigation into the behaviour of SF6 nozzle arc. It is concerned with the aerodynamic and electrical behaviour of a transient nozzle arc under a current ramp specified by a rate of current decay (di/dt) before current zero and a voltage ramp (dV/dt) after current zero. The five flow models used in part I [1] for cold gas flow and DC nozzle arcs have been applied to study the transient arc at three stagnation pressures (P 0) and two values of di/dt for the current ramp, representing a wide range of arcing conditions. An analysis of the physical mechanisms encompassed in each flow model is given with an emphasis on the adequacy of a particular model in describing the rapidly varying arc around current zero. The critical rate of rise of recovery voltage (RRRV) is found computationally and compared with test results of Benenson et al [2]. For transient nozzle arcs, the RRRV is proportional to the square of P 0, rather than to the square root of P 0 for DC nozzle arcs. The physical mechanisms responsible for the strong dependence of RRRV on P 0 have been investigated. The relative merits of the flow models employed are discussed.

  3. Design and performance evaluation of a dual bell nozzle

    Science.gov (United States)

    Kbab, H.; Sellam, M.; Hamitouche, T.; Bergheul, S.; Lagab, L.

    2017-01-01

    The main objective of a dual bell nozzle is the enhancement of performances based on the principle of auto-adaptation in accordance with the altitude. Indeed, this system has as advantage the auto-adaptation of the flow for two operating modes (at low and high altitude) without mechanical activation. The principle is theoretically simple but structural forces involved can be significant. In this study, a numerical method for the design of this type of nozzle is developed. On the one hand, it is based on a transonic flow approaches to define the starting line on which the supersonic calculations will be initiated. On the other hand, the method of characteristics is used to draw the base nozzle profile. Knowing that the latter is assimilated as a polynomial of the second degree, its constants are calculated from initial conditions. In order to minimize the weight of this nozzle, its truncation proves necessary; this is performed at a point where the best compromise (weight / performances) was respected. The profile of the second curve is calculated to give a constant wall pressure. This is achieved by using the direct method of characteristics applied for a centered expansion wave that the intensity is P2/P1 at the junction. Once the profile is generated, an analysis of the thermodynamic-parameters evolution (such as: pressure, Mach number) and aerodynamic performances is conducted. For more consistency, our results are compared with numerical databases of ONERA nozzle. Simulations of flow in the nozzle with Ansys 13.0 environment for different types of meshes are presented. Also, to offset the effects of the boundary layer, the simulations were performed by using the k-ω SST turbulence model. The obtained results by the method of characteristics and numerical simulation are compared to the computed results of the literature and it was found good agreement and similarity.

  4. Experimental Investigation of 'Transonic Resonance' with Convergent-Divergent Nozzles

    Science.gov (United States)

    Zaman, K. B. M. Q.; Dahl, M. D.; Bencic, T. J.; Zaman, Khairul (Technical Monitor)

    2001-01-01

    Convergent-divergent nozzles, when run at pressure ratios lower than the design value, often undergo a flow resonance accompanied by the emission of acoustic tones. The phenomenon, different in characteristics from conventional 'screech' tones, has been studied experimentally. Unlike screech, the frequency increases with increasing supply pressure. There is a 'staging' behavior; 'odd harmonic' stages resonate at lower pressures while the fundamental occurs in a range of higher pressures corresponding to a fully expanded Mach number (M(sub j)) around unity. The frequency (f(sub N)) variation with M(sub j) depends on the half angle-of-divergence (theta) of the nozzle. At smaller theta, the slope of f(sub N) versus M(sub j) curve becomes steeper. The resonance involves standing waves and is driven by unsteady shock/boundary layer interaction. The distance between the foot of the shock and the nozzle exit imposes the lengthscale (L'). The fundamental corresponds to a quarterwave resonance, the next stage at a lower supply pressure corresponds to a three-quarter-wave resonance, and so on. The principal trends in the frequency variation are explained simply from the characteristic variation of the length-scale L'. Based on the data, correlation equations are provided for the prediction of f(sub N). A striking feature is that tripping of the boundary layer near the nozzle's throat tends to suppress the resonance. In a practical nozzle a tendency for the occurrence of the phenomenon is thought to be a source of 'internal noise'; thus, there is a potential for noise benefit simply by appropriate boundary layer tripping near the nozzle's throat.

  5. Development of the Planar Inlet Design and Analysis Process (PINDAP)

    Science.gov (United States)

    Gruber, Christopher R.

    2004-01-01

    The aerodynamic development of an engine inlet requires a comprehensive program of both wind tunnel testing and Computational Fluid Dynamics (CFD) simulations. To save time and resources, much "testing" is done using CFD before any design ever enters a wind tunnel. The focus of my project this summer is on CFD analysis tool development. In particular, I am working to further develop the capabilities of the Planar Inlet Design and Analysis Process (PINDAP). "PINDAP" is a collection of computational tools that allow for efficient and accurate design and analysis of the aerodynamics about and through inlets that can make use of a planar (two-dimensional or axisymmetric) geometric and flow assumption. PINDAP utilizes the WIND CFD flow solver, which is capable of simulating the turbulent, compressible flow field. My project this summer is a continuation of work that I performed for two previous summers. Two years ago, I used basic features of the PINDAP to design a Mach 5 hypersonic scramjet engine inlet and to demonstrate the feasibility of the PINDAP. The following summer, I worked to develop its geometry and grid generation capabilities to include subsonic and supersonic inlets, complete bodies and cowls, conic leading and trailing edges, as well as airfoils. These additions allowed for much more design flexibility when using the program.

  6. Passive acoustic monitoring of Cook Inlet beluga whales (Delphinapterus leucas).

    Science.gov (United States)

    Lammers, Marc O; Castellote, Manuel; Small, Robert J; Atkinson, Shannon; Jenniges, Justin; Rosinski, Anne; Oswald, Julie N; Garner, Chris

    2013-09-01

    The endangered beluga whale (Delphinapterus leucas) population in Cook Inlet, AK faces threats from a variety of anthropogenic factors, including coastal development, oil and gas exploration, vessel traffic, and military activities. To address existing gaps in understanding about the occurrence of belugas in Cook Inlet, a project was developed to use passive acoustic monitoring to document the year-round distribution of belugas, as well as killer whales (Orcinus orca), which prey on belugas. Beginning in June 2009, ten moorings were deployed throughout the Inlet and refurbished every two to eight months. Despite challenging conditions consisting of strong tidal currents carrying debris and seasonal ice cover, 83% of mooring deployments were successfully recovered. Noise from water flow, vessel traffic, and/or industrial activities was present at several sites, potentially masking some signals. However, belugas were successfully detected at multiple locations. Detections were relatively common in the upper inlet and less common or absent at middle and lower inlet locations. Killer whale signals were also recorded. Some seasonal variability in the occurrence of both belugas and killer whales was evident.

  7. Transmission geometry laserspray ionization vacuum using an atmospheric pressure inlet.

    Science.gov (United States)

    Lutomski, Corinne A; El-Baba, Tarick J; Inutan, Ellen D; Manly, Cory D; Wager-Miller, James; Mackie, Ken; Trimpin, Sarah

    2014-07-01

    This represents the first report of laserspray ionization vacuum (LSIV) with operation directly from atmospheric pressure for use in mass spectrometry. Two different types of electrospray ionization source inlets were converted to LSIV sources by equipping the entrance of the atmospheric pressure inlet aperture with a customized cone that is sealed with a removable glass plate holding the matrix/analyte sample. A laser aligned in transmission geometry (at 180° relative to the inlet) ablates the matrix/analyte sample deposited on the vacuum side of the glass slide. Laser ablation from vacuum requires lower inlet temperature relative to laser ablation at atmospheric pressure. However, higher inlet temperature is required for high-mass analytes, for example, α-chymotrypsinogen (25.6 kDa). Labile compounds such as gangliosides and cardiolipins are detected in the negative ion mode directly from mouse brain tissue as intact doubly deprotonated ions. Multiple charging enhances the ion mobility spectrometry separation of ions derived from complex tissue samples.

  8. Numerical study on drop formation through a micro nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Il; Son, Gi Hun [Sogang Univ., Seoul (Korea, Republic of)

    2005-02-01

    The drop ejection process from a micro nozzle is investigated by numerically solving the conservation equations for mass and momentum. The liquid-gas interface is tracked by a level set method which is extended for two-fluid flows with irregular solid boundaries. Based on the numerical results, the liquid jet breaking and droplet formation behavior is found to depend strongly on the pulse type of forcing pressure and the contact angle at the gas-liquid-solid interline. The negative pressure forcing can be used to control the formation of satelite droplets. Also, various nozzle shapes are tested to investigate their effect on droplet formation.

  9. Ice Control with Brine Spread with Nozzles on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    . The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt. The spread pattern for every spreader, tested in The County of Funen, has been meassured 3 hours after...... spreading on a highway with traffic. A total of 800 spots were measured for residual salt for every spreader. The measurements and the spread pattern for brine spreading with nozzles were so precisely, that we learned: “When there is moisture, water or ice on the road, we need to take into account...

  10. Rocket nozzle thermal shock tests in an arc heater facility

    Science.gov (United States)

    Painter, James H.; Williamson, Ronald A.

    1986-01-01

    A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

  11. Effect of nozzle geometry on the resistojet exhaust plume

    Science.gov (United States)

    Breyley, Loranell; Serafini, John S.; Hoffman, David J.; Zana, Lynette M.

    1987-01-01

    Five nozzle configurations were used to study the effect of geometry on the plume structure of a resistojet exhausting into a vacuum. Mass flux data in the forward and back flux regions were obtained with a cryogenically cooled quartz crystal microbalance. The propellant used was CO2 at 300 K and a mass flow rate of 0.2 g/s. The data reveal that the percent of mass flow contained within half angles of 10, 30, and 40 deg varied by less than 12 percent from a standard 20 deg half-angle cone nozzle.

  12. Intensification of heat transfer by changing the burner nozzle

    Science.gov (United States)

    DzurÅák, Róbert; Kizek, Ján; Jablonský, Gustáv

    2016-06-01

    Thermal aggregates are using burner which burns combustible mixture with an oxidizing agent, by adjustment of the burner nozzle we can achieve better conditions of combustion to intensify heat transfer at furnace space. The aim of the present paper was using a computer program Ansys Workbench to create a computer simulation which analyzes the impact of the nozzle on the shape of a flame thereby intensifies heat transfer in rotary drum furnaces and radiation heat transfer from the flue gas into the furnace space. Article contains analysis of the geometry of the burner for achieving temperature field in a rotary drum furnace using oxy-combustion and the practical results of computer simulations

  13. Analytical study of nozzle performance for nuclear thermal rockets

    Science.gov (United States)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    A parametric study has been conducted by the NASA-Lewis Rocket Engine Design Expert System for the convergent-divergent nozzle of the Nuclear Thermal Rocket system, which uses a nuclear reactor to heat hydrogen to high temperature and then expands it through the nozzle. It is established by the study that finite-rate chemical reactions lower performance levels from theoretical levels. Major parametric roles are played by chamber temperature and chamber pressure. A maximum performance of 930 sec is projected at 2700 K, and of 1030 at 3100 K.

  14. Injection nozzle materials for a coal-fueled diesel locomotive

    Energy Technology Data Exchange (ETDEWEB)

    Mehan, R.L.; Leonard, G.L.; Johnson, R.N.; Lavigne, R.G.

    1990-12-31

    In order to identify materials resistant to coal water mixture (CWM) erosive wear, a number of materials were evaluated using both orifice slurry and dry air erosion tests. Both erosion tests ranked materials in the same order, and the most erosion resistant material identified was sintered diamond compact. Based on operation using CWM in a single-cylinder locomotive test, superhard nozzle materials such as diamond, cubic boron nitride, and perhaps TiB{sub 2} were found to be necessary in order to obtain a reasonable operating life. An injection nozzle using sintered diamond compacts was designed and built, and has operated successfully in a CWM fired locomotive engine.

  15. Jet Engine Nozzle Exit Configurations and Associated Systems and Methods

    Science.gov (United States)

    Mengle, Vinod G. (Inventor)

    2013-01-01

    Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter.

  16. Advanced nozzle characterization for hydrogen fluoride overtone chemical lasers

    Science.gov (United States)

    Duncan, William A.; Patterson, Stanley P.; Graves, Bruce R.; Sollee, Jeffrey L.; Yonehara, Gordon N.; Dering, John P.

    1992-07-01

    The parametric characterization and optimization of the hypersonic, low-temperature (HYLTE) nozzle concept for the hydrogen fluoride (HF) overtone and HF fundamental performance are reviewed. The HF fundamental space-based laser for weapons systems is considered to be more mature, nearer term potential application than the overtone. Emphasis is placed on the Task 3 advanced gain generator technology configurations (AGGTC) aimed at a thorough characterization in the fundamental regime. The experiments were based on advanced multilayer dielectric coatings on uncooled silicon substrates. It is concluded that the Task 3 AGGTC hardware functioned quite well in optimizing the performance of the HYLTE nozzle concept.

  17. Sedimentological and Geophysical Signatures of a Relict Tidal Inlet along a Wave-Dominated Barrier, Assateague Island, Maryland, USA

    Science.gov (United States)

    Seminack, C. T.; Buynevich, I. V.; Grimes, Z. T.; Griffis, N.; Goble, R. J.

    2010-12-01

    Assateague Island is a classic example of a retrograding barrier island, with its recent geological history punctuated by episodes of overwash and breaching. However, in addition to a number of historical inlets, parts of the island may owe their origin to relict (pre-historic) channels. The present study was conducted north of the Virginia-Maryland border, focusing on a narrow segment of the island fronting the Green Run Bay. The site lies north of the historical Green Run Inlet that was active until 1880, however, there is no geological evidence that it migrated southward from the Green Run Bay. More than 4 km of high-resolution ground-penetrating radar (GPR) images, complemented with sediment cores and multi-dating techniques, were used to reconstruct the geological legacy of this older barrier segment. Our findings suggest that a backbarrier paleo-channel still visible within the Green Run Bay corresponds to a large (>380 m wide, 3.0-3.5 m thick) channel cut-and-fill structure revealed in GPR images. The channel fill consists of tangential- to sigmoidal-oblique, southward-dipping reflections downlapping onto channel lag facies, which overlie subhorizontal bay-fill strata. Hummocky reflections in a shore-normal channel transect suggest partial preservation of inlet-related bedforms, believed to be associated with the channel closure. Radiocarbon samples of Mollusk shells from the bay fill yield radiocarbon ages of 4630-2400 cal BP (calibrated years before 1950). The paleo-channel facies overlying the bay deposits exhibits a fining-upward sequence, with a mean grain size range of 0.44-2.43 φ. The first set of optical dates indicates that the inlet fill is 660±70 cal BP (AD 1220-1360). The paleo-channel fill does not extend to the south and therefore is a separate relict feature that predates the historical Green Run Inlet. Based on geophysical and core data, the paleo-tidal prism of the relict channel is 17x106 m3. Following the closure of the inlet, a series

  18. DURACON - Variable Emissivity Broadband Coatings for Liquid Propellant Rocket Nozzles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The need exists for a fast drying, robust, low gloss, black, high emissivity coating that can be applied easily on aircraft rocket nozzles and nozzle extensions....

  19. Computational Simulation on a Coaxial Substream Powder Feeding Laval Nozzle of Cold Spraying

    Directory of Open Access Journals (Sweden)

    Guosheng HUANG

    2014-09-01

    Full Text Available In this paper, a substream coaxial powder feeding nozzle was investigated for use in cold spraying. The relationship between nozzle structure and gas flow, the acceleration behavior of copper particles were examined by computational simulation method. Also, one of the nozzle was used to spray copper coating on steel substrate. The simulation results indicate that: the velocity of gas at the center of the nozzle is lower than that of the conventional nozzle. Powders are well restrained near the central line of the nozzle, no collision occurred between the nozzle wall and the powders. This type of nozzle with expansion 3.25 can successfully deposit copper coating on steel substrate, the copper coating has low porosity about 3.1 % – 3.8 % and high bonding strength about 23.5 MPa – 26.8 MPa. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4244

  20. Structure Optimization and Numerical Simulation of Nozzle for High Pressure Water Jetting

    Directory of Open Access Journals (Sweden)

    Shuce Zhang

    2015-01-01

    Full Text Available Three kinds of nozzles normally used in industrial production are numerically simulated, and the structure of nozzle with the best jetting performance out of the three nozzles is optimized. The R90 nozzle displays the most optimal jetting properties, including the smooth transition of the nozzle’s inner surface. Simulation results of all sample nozzles in this study show that the helix nozzle ultimately displays the best jetting performance. Jetting velocity magnitude along Y and Z coordinates is not symmetrical for the helix nozzle. Compared to simply changing the jetting angle, revolving the jet issued from the helix nozzle creates a grinding wheel on the cleaning surface, which makes not only an impact effect but also a shearing action on the cleaning object. This particular shearing action improves the cleaning process overall and forms a wider, effective cleaning range, thus obtaining a broader jet width.

  1. Internal performance of two nozzles utilizing gimbal concepts for thrust vectoring

    Science.gov (United States)

    Berrier, Bobby L.; Taylor, John G.

    1990-01-01

    The internal performance of an axisymmetric convergent-divergent nozzle and a nonaxisymmetric convergent-divergent nozzle, both of which utilized a gimbal type mechanism for thrust vectoring was evaluated in the Static Test Facility of the Langley 16-Foot Transonic Tunnel. The nonaxisymmetric nozzle used the gimbal concept for yaw thrust vectoring only; pitch thrust vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps. The model geometric parameters investigated were pitch vector angle for the axisymmetric nozzle and pitch vector angle, yaw vector angle, nozzle throat aspect ratio, and nozzle expansion ratio for the nonaxisymmetric nozzle. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 12.0.

  2. Grounded theory.

    Science.gov (United States)

    Harris, Tina

    2015-04-29

    Grounded theory is a popular research approach in health care and the social sciences. This article provides a description of grounded theory methodology and its key components, using examples from published studies to demonstrate practical application. It aims to demystify grounded theory for novice nurse researchers, by explaining what it is, when to use it, why they would want to use it and how to use it. It should enable nurse researchers to decide if grounded theory is an appropriate approach for their research, and to determine the quality of any grounded theory research they read.

  3. Performance characteristics of two multiaxis thrust-vectoring nozzles at Mach numbers up to 1.28

    Science.gov (United States)

    Wing, David J.; Capone, Francis J.

    1993-01-01

    The thrust-vectoring axisymmetric (VA) nozzle and a spherical convergent flap (SCF) thrust-vectoring nozzle were tested along with a baseline nonvectoring axisymmetric (NVA) nozzle in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0 to 1.28 and nozzle pressure ratios from 1 to 8. Test parameters included geometric yaw vector angle and unvectored divergent flap length. No pitch vectoring was studied. Nozzle drag, thrust minus drag, yaw thrust vector angle, discharge coefficient, and static thrust performance were measured and analyzed, as well as external static pressure distributions. The NVA nozzle and the VA nozzle displayed higher static thrust performance than the SCF nozzle throughout the nozzle pressure ratio (NPR) range tested. The NVA nozzle had higher overall thrust minus drag than the other nozzles throughout the NPR and Mach number ranges tested. The SCF nozzle had the lowest jet-on nozzle drag of the three nozzles throughout the test conditions. The SCF nozzle provided yaw thrust angles that were equal to the geometric angle and constant with NPR. The VA nozzle achieved yaw thrust vector angles that were significantly higher than the geometric angle but not constant with NPR. Nozzle drag generally increased with increases in thrust vectoring for all the nozzles tested.

  4. Boundary conditions for free surface inlet and outlet problems

    KAUST Repository

    Taroni, M.

    2012-08-10

    We investigate and compare the boundary conditions that are to be applied to free-surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well known that the flux scales with Ca 2/3, but this classical result is non-uniform as the contact angle approaches π. By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed. © 2012 Cambridge University Press.

  5. Flow hydrodynamics near inlet key of Piano Key Weir (PKW)

    Indian Academy of Sciences (India)

    Harinarayan Tiwari; Nayan Sharma

    2015-10-01

    This paper presents fundamental outcomes from an experimental study on the hydrodynamic performance near inlet key of Piano Key Weir (PKW). Hydrodynamic performance was tested in a circulated open channel that comprised of PKW and sand bed (d50 = 0.25 mm). Instantaneous velocities were measured at 20 cross sections using Laser Doppler Velocimeter (LDV) with constant discharge and depth. Average velocity and turbulence intensities in both directions were investigated. Average longitudinal velocities are found very much consistent at every point and maximum around the midway of inlet key. In transverse direction, flow is bifurcating in two directions which are also confirmed by average transverse velocity estimation. Variation of turbulence intensity presents average 10 times higher transverse turbulence than longitudinal turbulence near inlet key of PKW.

  6. Simulation of combustion products flow in the Laval nozzle in the software package SIFIN

    Science.gov (United States)

    Alhussan, K. A.; Teterev, A. V.

    2017-07-01

    Developed specialized multifunctional software package SIFIN (Simulation of Internal Flow In the Nozzle) designed for the numerical simulation of the flow of products of combustion in a Laval nozzle. It allows to design the different profiles of the nozzles, to simulate flow of multicomponent media based energy release by burning, to study the effect of swirling flow of products of combustion at the nozzle settings, to investigate the nature of the expiry of the gas jet with varying degrees of pressure ratio.

  7. The model of the mechanical interaction of particles with the combustion products in a nozzle

    Science.gov (United States)

    Teterev, A. V.; Mandrik, P. A.; Misuchenko, N. I.; Rudak, L. V.

    2017-07-01

    This article describes the development of model of interaction of condensed particles with the gas flow in the Laval nozzle. Conducted parametric calculations have shown that the interaction of particles with the combustion products, even with a relatively small volume content may lead to a qualitative change in the internal flow in the Laval nozzle, and thereby influence the characteristics of the nozzle.

  8. Effect of spray nozzle design on fish oil-whey protein microcapsule properties.

    Science.gov (United States)

    Legako, Jerrad; Dunford, Nurhan Turgut

    2010-08-01

    Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.

  9. Nozzle design in a fiber spinning process for a maximal pressure gradient

    Directory of Open Access Journals (Sweden)

    Yang Zhanping

    2013-01-01

    Full Text Available The thickness of a spinneret is always a geometrical constraint in nozzle design. The geometrical form of a nozzle has a significant effect on the subsequent spinning characteristics. This paper gives an optimal condition for maximal pressure gradient through the nozzle.

  10. Effects of dimensional size and surface roughness on service performance for a micro Laval nozzle

    Science.gov (United States)

    Cai, Yukui; Liu, Zhanqiang; Shi, Zhenyu

    2017-05-01

    Nozzles with large and small dimensions are widely used in various industries. The main objective of this research is to investigate the effects of dimensional size and surface roughness on the service performance of a micro Laval nozzle. The variation of nozzle service performance from the conventional macro to micro scale is presented in this paper. This shows that the dimensional nozzle size has a serious effect on the nozzle gas flow friction. With the decrease of nozzle size, the velocity performance and thrust performance deteriorate. The micro nozzle performance has less sensitivity to the variation of surface roughness than the large scale nozzle does. Surface quality improvement and burr prevention technologies are proposed to reduce the friction effect on the micro nozzle performance. A novel process is then developed to control and depress the burr generation during micro nozzle machining. The polymethyl-methacrylate as a coating material is coated on the rough machined surface before finish machining. Finally, the micro nozzle with a throat diameter of 1 mm is machined successfully. Thrust test results show that the implement and application of this machining process benefit the service performance improvement of the micro nozzle.

  11. Marine benthic habitat mapping of Muir Inlet, Glacier Bay National Park and Preserve, Alaska, with an evaluation of the Coastal and Marine Ecological Classification Standard III

    Science.gov (United States)

    Trusel, Luke D.; Cochrane, Guy R.; Etherington, Lisa L.; Powell, Ross D.; Mayer, Larry A.

    2010-01-01

    Seafloor geology and potential benthic habitats were mapped in Muir Inlet, Glacier Bay National Park and Preserve, Alaska, using multibeam sonar, ground-truth information, and geological interpretations. Muir Inlet is a recently deglaciated fjord that is under the influence of glacial and paraglacial marine processes. High glacially derived sediment and meltwater fluxes, slope instabilities, and variable bathymetry result in a highly dynamic estuarine environment and benthic ecosystem. We characterize the fjord seafloor and potential benthic habitats using the Coastal and Marine Ecological Classification Standard (CMECS) recently developed by the National Oceanic and Atmospheric Administration (NOAA) and NatureServe. Substrates within Muir Inlet are dominated by mud, derived from the high glacial debris flux. Water-column characteristics are derived from a combination of conductivity temperature depth (CTD) measurements and circulation-model results. We also present modern glaciomarine sediment accumulation data from quantitative differential bathymetry. These data show Muir Inlet is divided into two contrasting environments: a dynamic upper fjord and a relatively static lower fjord. The accompanying maps represent the first publicly available high-resolution bathymetric surveys of Muir Inlet. The results of these analyses serve as a test of the CMECS and as a baseline for continued mapping and correlations among seafloor substrate, benthic habitats, and glaciomarine processes.

  12. Acoustic measurements of models of military style supersonic nozzle jets

    Directory of Open Access Journals (Sweden)

    Ching-Wen Kuo

    2014-02-01

    Full Text Available Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. However, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometries of these nozzles. Thus the present effort at Pennsylvania State University (PSU in partnership with GE Aviation and the NASA Glenn Research Center is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles, and to identify and test promising noise reduction techniques. An equally important objective is to develop methodology for using data obtained from small- and moderate-scale experiments to reliably predict the full-scale engine noise. The experimental results presented show reasonable agreement between small-scale and medium-scale jets, as well as between heated jets and heat-simulated ones.

  13. Vortex structures downstream a lobed nozzle/mixer

    Institute of Scientific and Technical Information of China (English)

    Hui Hu; Toshio Kobayashi

    2008-01-01

    An experimental study was conducted to investigate the evolutions of unsteady vortex structures downstream a lobed mixer/nozzle. A novel dual-plane stereoscopic PIV system was used to measure all 3-components of vorticity distributions to revealed both the large-scale streamwise vortices produced by the lobed mixer/nozzle and the Kelvin-Helmholtz vortex structures generated due to the Kelvin-Helmholtz instabilities simultaneously and quantitatively for the first time. The instantaneous and the ensemble-averaged vorticity distributions displayed quite different aspects about the evolutions of the unsteady vortex structures. While the ensemble-averaged vorticity distributions indicated the overall effect of the special geometry of the lobed nozzle/mixer on the enhanced mixing process, the instantaneous vorticity distributions elucidated many details about how the enhanced mixing process was conducted. In addition to quantitatively confirming conjectures of previous studies, further insight about the formation, evolution and interaction characteristics of the unsteady vortex structures downstream of the lobed mixer/nozzle were also uncovered quantitatively in the present study.

  14. Liquid Atomization out of a Full Cone Pressure Swirl Nozzle

    CERN Document Server

    Rimbert, Nicolas

    2010-01-01

    A thorough numerical, theoretical and experimental investigation of the liquid atomization in a full cone pressure swirl nozzle is presented. The first part is devoted to the study of the inner flow. CAD and CFD software are used in order to determine the most important parameters of the flow at the exit of nozzle. An important conclusion is the existence of two flow regions: one in relatively slow motion (the boundary layer) and a second nearly in solid rotation at a very high angular rate (about 100 000 rad/s) with a thickness of about 4/5th of the nozzle section. Then, a theoretical and experimental analysis of the flow outside the nozzle is carried out. In the theoretical section, the size of the biggest drops is successfully compared to results stemming from linear instability theory. However, it is also shown that this theory cannot explain the occurrence of small drops observed in the stability domain whose size are close to the Kolmogorov and Taylor turbulent length scale. A Phase Doppler Particle Ana...

  15. Numerical modeling of a compressible multiphase flow through a nozzle

    Science.gov (United States)

    Niedzielska, Urszula; Rabinovitch, Jason; Blanquart, Guillaume

    2012-11-01

    New thermodynamic cycles developed for more efficient low temperature resource utilization can increase the net power production from geothermal resources and sensible waste heat recovery by 20-40%, compared to the traditional organic Rankine cycle. These improved systems consist of a pump, a liquid heat exchanger, a two-phase turbine, and a condenser. The two-phase turbine is used to extract energy from a high speed multiphase fluid and consists of a nozzle and an axial impulse rotor. In order to model and optimize the fluid flow through this part of the system an analysis of two-phase flow through a specially designed convergent-divergent nozzle has to be conducted. To characterize the flow behavior, a quasi-one-dimensional steady-state model of the multiphase fluid flow through a nozzle has been constructed. A numerical code capturing dense compressible multiphase flow under subsonic and supersonic conditions and the coupling between both liquid and gas phases has been developed. The output of the code delivers data vital for the performance optimization of the two-phase nozzle.

  16. Investigation of nozzle contours in the CSIR supersonic wind tunnel

    CSIR Research Space (South Africa)

    Vallabh, Bhavya

    2017-09-01

    Full Text Available method developed to improve the flow quality in the test section region subject to the HSWT’s limitations. The wind tunnel geometry and constraints were employed in accordance with the Sivells’ nozzle design method and the method of characteristics...

  17. Study of Liquid Breakup Process in Solid Rocket Motor Nozzle

    Science.gov (United States)

    2016-02-16

    34Chemical Erosion of Refractory - Metal Nozzle Inserts in Solid-Propellant Rocket Motors," J. Propulsion and Power, Vol. 25, no.1,, 2009. [4] E. Y. Wong...Paul A.;, "Gelcasting of Alumina," J. Am. Ceram . Soc. 74[3], pp. 612-618, 1991. [18] Blomquist , B. A.; Fink, J. K.; Leibowitz, L.;, "The

  18. Cavitation Inside High-Pressure Optically Transparent Fuel Injector Nozzles

    Science.gov (United States)

    Falgout, Z.; Linne, M.

    2015-12-01

    Nozzle-orifice flow and cavitation have an important effect on primary breakup of sprays. For this reason, a number of studies in recent years have used injectors with optically transparent nozzles so that orifice flow cavitation can be examined directly. Many of these studies use injection pressures scaled down from realistic injection pressures used in modern fuel injectors, and so the geometry must be scaled up so that the Reynolds number can be matched with the industrial applications of interest. A relatively small number of studies have shown results at or near the injection pressures used in real systems. Unfortunately, neither the specifics of the design of the optical nozzle nor the design methodology used is explained in detail in these papers. Here, a methodology demonstrating how to prevent failure of a finished design made from commonly used optically transparent materials will be explained in detail, and a description of a new design for transparent nozzles which minimizes size and cost will be shown. The design methodology combines Finite Element Analysis with relevant materials science to evaluate the potential for failure of the finished assembly. Finally, test results imaging a cavitating flow at elevated pressures are presented.

  19. Shock unsteadiness in a thrust optimized parabolic nozzle

    Science.gov (United States)

    Verma, S. B.

    2009-07-01

    This paper discusses the nature of shock unsteadiness, in an overexpanded thrust optimized parabolic nozzle, prevalent in various flow separation modes experienced during start up {(δ P0 /δ t > 0)} and shut down {(δ P0/δ t tube. Shock unsteadiness in the separation region is seen to increase significantly just before the onset of each flow transition, even during steady nozzle operation. The intensity of this measure ( rms level) is seen to be strongly influenced by relative locations of normal and overexpansion shock, the decrease in radial size of re-circulation zone in the back-flow region, and finally, the local nozzle wall contour. During restricted shock separation, the pressure fluctuations in separation region exhibit periodic characteristics rather than the usually observed characteristics of intermittent separation. The possible physical mechanisms responsible for the generation of flow unsteadiness in various separation modes are discussed. The results are from an experimental study conducted in P6.2 cold-gas subscale test facility using a thrust optimized parabolic nozzle of area-ratio 30.

  20. Coherent entropy induced and acoustic noise separation in compact nozzles

    Science.gov (United States)

    Tao, Wenjie; Schuller, Thierry; Huet, Maxime; Richecoeur, Franck

    2017-04-01

    A method to separate entropy induced noise from an acoustic pressure wave in an harmonically perturbed flow through a nozzle is presented. It is tested on an original experimental setup generating simultaneously acoustic and temperature fluctuations in an air flow that is accelerated by a convergent nozzle. The setup mimics the direct and indirect noise contributions to the acoustic pressure field in a confined combustion chamber by producing synchronized acoustic and temperature fluctuations, without dealing with the complexity of the combustion process. It allows generating temperature fluctuations with amplitude up to 10 K in the frequency range from 10 to 100 Hz. The noise separation technique uses experiments with and without temperature fluctuations to determine the relative level of acoustic and entropy fluctuations in the system and to identify the nozzle response to these forcing waves. It requires multi-point measurements of acoustic pressure and temperature. The separation method is first validated with direct numerical simulations of the nonlinear Euler equations. These simulations are used to investigate the conditions for which the separation technique is valid and yield similar trends as the experiments for the investigated flow operating conditions. The separation method then gives successfully the acoustic reflection coefficient but does not recover the same entropy reflection coefficient as predicted by the compact nozzle theory due to the sensitivity of the method to signal noises in the explored experimental conditions. This methodology provides a framework for experimental investigation of direct and indirect combustion noises originating from synchronized perturbations.

  1. SHINE Tritium Nozzle Design: Activity 6, Task 1 Report

    Energy Technology Data Exchange (ETDEWEB)

    Okhuysen, Brett S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pulliam, Elias Noel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-05

    In FY14, we studied the qualitative and quantitative behavior of a SHINE/PNL tritium nozzle under varying operating conditions. The result is an understanding of the nozzle’s performance in terms of important flow features that manifest themselves under different parametric profiles. In FY15, we will consider nozzle design with a focus on nozzle geometry and integration. From FY14 work, we will understand how the SHINE/PNL nozzle behaves under different operating scenarios. The first task for FY15 is to evaluate the FY14 model as a predictor of the actual flow. Considering different geometries is more time-intensive than parameter studies, therefore we recommend considering any relevant flow features that were not included in the FY14 model. In the absence of experimental data, it is particularly important to consider any sources of heat in the domain or boundary conditions that may affect the flow and incorporate these into the simulation if they are significant. Additionally, any geometric features of the beamline segment should be added to the model such as the orifice plate. The FY14 model works with hydrogen. An improvement that can be made for FY15 is to develop CFD properties for tritium and incorporate those properties into the new models.

  2. Equilibrium retention in the nozzle of oxygen hydrogen propulsion systems

    Science.gov (United States)

    Ford, D. I.

    1987-01-01

    Arguments are presented for the retention of vibrational equilibrium of species in the nozzle of the Space Shuttle Main Engine which are especially applicable to water and the hydroxyl radical. It is shown that the reaction OH + HH yields HOH + H maintains equilibrium as well. This is used to relate OH to H, the temperature, and the oxidizer-to-fuel ratio.

  3. Acoustic measurements of models of military style supersonic nozzle jets

    Institute of Scientific and Technical Information of China (English)

    Ching-Wen Kuo; Jérémy Veltin; Dennis K. McLaughlin

    2014-01-01

    Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. How-ever, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometries of these nozzles. Thus the present effort at Pennsylvania State University (PSU) in partnership with GE Aviation and the NASA Glenn Research Center is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles, and to identify and test promising noise reduction techniques. An equally important objective is to develop methodology for using data obtained from small-and moderate-scale experiments to reliably predict the full-scale engine noise. The experimental results presented show reasonable agreement between small-scale and medium-scale jets, as well as between heated jets and heat-simulated ones.

  4. Augustine Volcano, Cook Inlet, Alaska (January 12, 2006)

    Science.gov (United States)

    2006-01-01

    Since last spring, the U.S. Geological Survey's Alaska Volcano Observatory (AVO) has detected increasing volcanic unrest at Augustine Volcano in Cook Inlet, Alaska near Anchorage. Based on all available monitoring data, AVO regards that an eruption similar to 1976 and 1986 is the most probable outcome. During January, activity has been episodic, and characterized by emission of steam and ash plumes, rising to altitudes in excess of 9,000 m (30,000 ft), and posing hazards to aircraft in the vicinity. An ASTER image was acquired at 12:42 AST on January 12, 2006, during an eruptive phase of Augustine. The perspective rendition shows the eruption plume derived from the ASTER image data. ASTER's stereo viewing capability was used to calculate the 3-dimensional topography of the eruption cloud as it was blown to the south by prevailing winds. From a maximum height of 3060 m (9950 ft), the plume cooled and its top descended to 1900 m (6175 ft). The perspective view shows the ASTER data draped over the plume top topography, combined with a base image acquired in 2000 by the Landsat satellite, that is itself draped over ground elevation data from the Shuttle Radar Topography Mission. The topographic relief has been increased 1.5 times for this illustration. Comparison of the ASTER plume topography data with ash dispersal models and weather radar data will allow the National Weather Service to validate and improve such models. These models are used to forecast volcanic ash plume trajectories and provide hazard alerts and warnings to aircraft in the Alaska region. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with

  5. Grounded cognition.

    Science.gov (United States)

    Barsalou, Lawrence W

    2008-01-01

    Grounded cognition rejects traditional views that cognition is computation on amodal symbols in a modular system, independent of the brain's modal systems for perception, action, and introspection. Instead, grounded cognition proposes that modal simulations, bodily states, and situated action underlie cognition. Accumulating behavioral and neural evidence supporting this view is reviewed from research on perception, memory, knowledge, language, thought, social cognition, and development. Theories of grounded cognition are also reviewed, as are origins of the area and common misperceptions of it. Theoretical, empirical, and methodological issues are raised whose future treatment is likely to affect the growth and impact of grounded cognition.

  6. Micro-Ramps for External Compression Low-Boom Inlets

    Science.gov (United States)

    Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.

    2010-01-01

    The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.

  7. Open inlet conversion: Water quality benefits of two designs

    Science.gov (United States)

    Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for movement of sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine the reduction in drainage effluent total suspended sediment (TSS) and phosphorus (P) concentr...

  8. Validation of Helium Inlet Design for ITER Toroidal Field Coil

    CERN Document Server

    Boyer, C; Hamada, K; Foussat, A; Le Rest, M; Mitchell, N; Decool, P; Savary, F; Sgobba, S; Weiss, K-P

    2014-01-01

    The ITER organization has performed design and its validation tests on a helium inlet structure for the ITER Toroidal Field (TF) coil under collaboration with CERN, KIT, and CEA-Cadarache. Detailed structural analysis was performed in order to optimize the weld shape. A fatigue resistant design on the fillet weld between the shell covers and the jacket is an important point on the helium inlet structure. A weld filler material was selected based on tensile test at liquid helium temperature after Nb3Sn reaction heat treatment. To validate the design of the weld joint, fatigue tests at 7 K were performed using heat-treated butt weld samples. A pressure drop measurement of a helium inlet mock-up was performed by using nitrogen gas at room temperature in order to confirm uniform flow distribution and pressure drop characteristic. These tests have validated the helium inlet design. Based on the validation, Japanese and European Union domestic agencies, which have responsibilities of the TF coil procurement, are pr...

  9. HINCOF-1: a Code for Hail Ingestion in Engine Inlets

    Science.gov (United States)

    Gopalaswamy, N.; Murthy, S. N. B.

    1995-01-01

    One of the major concerns during hail ingestion into an engine is the resulting amount and space- and time-wise distribution of hail at the engine face for a given geometry of inlet and set of atmospheric and flight conditions. The appearance of hail in the capture streamtube is invariably random in space and time, with respect to size and momentum. During the motion of a hailstone through an inlet, a hailstone undergoes several processes, namely impact with other hailstones and material surfaces of the inlet and spinner, rolling and rebound following impact; heat and mass transfer; phase change; and shattering, the latter three due to friction and impact. Taking all of these factors into account, a numerical code, designated HINCOF-I, has been developed for determining the motion hailstones from the atmosphere, through an inlet, and up to the engine face. The numerical procedure is based on the Monte-Carlo method. The report presents a description of the code, along with several illustrative cases. The code can be utilized to relate the spinner geometry - conical or, more effective, elliptical - to the possible diversion of hail at the engine face into the bypass stream. The code is also useful for assessing the influence of various hail characteristics on the ingestion and distribution of hailstones over the engine face.

  10. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given ...

  11. Cross contamination in dual inlet isotope ratio mass spectrometers

    NARCIS (Netherlands)

    Meijer, H.A.J.; Neubert, R.E.M.; Visser, G.H.

    2000-01-01

    Since the early days of geochemical isotope ratio mass spectrometry there has always been the problem of cross contamination, i.e. the contamination of the sample gas with traces of reference gas land vice versa) in a dual inlet system and the analyzer itself. This was attributable to valve leakages

  12. Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Wang, Z.B.; Verhagen, H.J.; Thuy, V.T.T.

    2008-01-01

    Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK RU

  13. Characterization of Inlet Diffuser Performance for Stratified Thermal Storage

    Science.gov (United States)

    Cimbala, John M.; Bahnfleth, William; Song, Jing

    1999-11-01

    Storage of sensible heating or cooling capacity in stratified vessels has important applications in central heating and cooling plants, power production, and solar energy utilization, among others. In stratified thermal storage systems, diffusers at the top and bottom of a stratified tank introduce and withdraw fluid while maintaining a stable density gradient and causing as little mixing as possible. In chilled water storage applications, mixing during the formation of the thermocline near an inlet diffuser is the single greatest source of thermal losses. Most stratified chilled water storage tanks are cylindrical vessels with diffusers that are either circular disks that distribute flow radially outward or octagonal rings of perforated pipe that distribute flow both inward and outward radially. Both types produce gravity currents that are strongly influenced by the inlet Richardson number, but the significance of other parameters is not clear. The present investigation considers the dependence of the thermal performance of a perforated pipe diffuser on design parameters including inlet velocity, ambient and inlet fluid temperatures, and tank dimensions for a range of conditions representative of typical chilled water applications. Dimensional analysis is combined with a parametric study using results from computational fluid dynamics to obtain quantitative relationships between design parameters and expected thermal performance.

  14. Cross-sectional stability of double inlet systems

    NARCIS (Netherlands)

    Brouwer, R.L.

    2013-01-01

    Barrier coasts and their associated tidal inlet systems are a common feature in many parts of the world. They constitute dynamic environments that are in a continuous stage of adapting to the prevailing tide and wave conditions. Commonly, these coastal areas are densely populated and (partly) as a r

  15. Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system

    NARCIS (Netherlands)

    Lam, N.T.; Stive, M.J.F.; Wang, Z.B.; Verhagen, H.J.; Thuy, V.T.T.

    2008-01-01

    Hydrodynamics and morphodynamics of a seasonally forced tidal inlet system are investigated using numerical models. The ocean forcing including tidal and wave actions and sediment transport is simulated using Delft3D model. Fluvial processes in Delft3D are taken into account as results from SOBEK

  16. Physics of Acoustic Radiation from Jet Engine Inlets

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Envia, Edmane; Chien, Eugene W.

    2012-01-01

    Numerical simulations of acoustic radiation from a jet engine inlet are performed using advanced computational aeroacoustics (CAA) algorithms and high-quality numerical boundary treatments. As a model of modern commercial jet engine inlets, the inlet geometry of the NASA Source Diagnostic Test (SDT) is used. Fan noise consists of tones and broadband sound. This investigation considers the radiation of tones associated with upstream propagating duct modes. The primary objective is to identify the dominant physical processes that determine the directivity of the radiated sound. Two such processes have been identified. They are acoustic diffraction and refraction. Diffraction is the natural tendency for an acoustic wave to follow a curved solid surface as it propagates. Refraction is the turning of the direction of propagation of sound waves by mean flow gradients. Parametric studies on the changes in the directivity of radiated sound due to variations in forward flight Mach number and duct mode frequency, azimuthal mode number, and radial mode number are carried out. It is found there is a significant difference in directivity for the radiation of the same duct mode from an engine inlet when operating in static condition and in forward flight. It will be shown that the large change in directivity is the result of the combined effects of diffraction and refraction.

  17. Max Data Report Jet Stability versus Inlet Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Lomperski, S. [Argonne National Lab. (ANL), Argonne, IL (United States); Bremer, N. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    This document describes experiments investigating the effect of inlet geometry on the flow field within a glass tank where two jets mix and impinge upon the lid. The setup mimics the outlet plenum of a fast reactor where core exit flows of different temperatures can mix in ways that induce thermal cycling in neighboring structures.

  18. System and method having multi-tube fuel nozzle with differential flow

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Michael John; Johnson, Thomas Edward; Berry, Jonathan Dwight; York, William David

    2017-01-03

    A system includes a multi-tube fuel nozzle with a fuel nozzle body and a plurality of tubes. The fuel nozzle body includes a nozzle wall surrounding a chamber. The plurality of tubes extend through the chamber, wherein each tube of the plurality of tubes includes an air intake portion, a fuel intake portion, and an air-fuel mixture outlet portion. The multi-tube fuel nozzle also includes a differential configuration of the air intake portions among the plurality of tubes.

  19. Turbine combustor with fuel nozzles having inner and outer fuel circuits

    Science.gov (United States)

    Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo

    2013-12-24

    A combustor cap assembly for a turbine engine includes a combustor cap and a plurality of fuel nozzles mounted on the combustor cap. One or more of the fuel nozzles would include two separate fuel circuits which are individually controllable. The combustor cap assembly would be controlled so that individual fuel circuits of the fuel nozzles are operated or deliberately shut off to provide for physical separation between the flow of fuel delivered by adjacent fuel nozzles and/or so that adjacent fuel nozzles operate at different pressure differentials. Operating a combustor cap assembly in this fashion helps to reduce or eliminate the generation of undesirable and potentially harmful noise.

  20. Parametric Study of Afterbody/nozzle Drag on Twin Two-dimensional Convergent-divergent Nozzles at Mach Numbers from 0.60 to 1.20

    Science.gov (United States)

    Pendergraft, Odis C., Jr.; Burley, James R., II; Bare, E. Ann

    1986-01-01

    An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of upper and lower external nozzle flap geometry on the external afterbody/nozzle drag of nonaxisymmetric two-dimensional convergent-divergent exhaust nozzles having parallel external sidewalls installed on a generic twin-engine, fighter-aircraft model. Tests were conducted over a Mach number range from 0.60 to 1.20 and over an angle-of-attack range from -5 to 9 deg. Nozzle pressure ratio was varied from jet off (1.0) to approximately 10.0, depending on Mach number.

  1. Coarse mode aerosol measurement using a Low Turbulence Inlet

    Science.gov (United States)

    Brooke, J.; Bart, M.; Trembath, J.; McQuaid, J. B.; Brooks, B. J.; Osborne, S.

    2012-04-01

    The Sahara desert is a major natural source of global mineral dust emissions (Forster et al., 2007) through the mobilisation and lifting of dust particles into the atmosphere from dust storms. A significant fraction of this dust is in the aerosol coarse mode (Weinzierl et al., 2009). It is highlighted of the difficulty in making accurate and reliable measurements from an aircraft platform, particularly that of coarse mode aerosol (Wendisch et al., 2004). To achieve the measurement of a representative aerosol sample an aerosol inlet, on an aircraft, is required for the delivery of the sample to the instruments making the measurements. Inlet design can modify aerosol size distribution through either underestimating due to aerosol losses or overestimation due to enhancements. The Low Turbulence Inlet (LTI) was designed to improve inlet efficiency. This is achieved by reducing turbulence flow within the tip of the inlet, reducing impaction of particles to the walls of the inlet (Wilson et al., 2004). The LTI further maintains isokinetic sampling flow (free stream velocity, U0 and sampling velocity, U are equal to 1). Dust aerosol over the Sahara desert provides an excellent environment to test and quantify the capabilities of the LTI on the FAAM BAe 146, whilst enabling in-situ dust measurement. The LTI was operated during the Fennec field campaign in June 2011 with 11 flights during the campaign over Mauritania and Mali. We are using the LTI to provide critical information on the sampling characteristics of the inlet used by nearly all aerosol instruments inside the aircraft (AMS, Nephelometer, PSAP, and CCN). Inlet experiments were performed with identical Optical Particle Counters (OPC) connected to the rosemount and LTI with size distribution for each inlet measured and Rosemount enhancements determined. Rosemount inlet enhancements were determined to be 2 to 4 times for particles up to 2.5 µm. A key parameter in aerosol measurement is size distribution, in which

  2. Flow Separation and Numerical Simulation of Solid Rocket Motor Nozzle%固体火箭发动机喷管分离流动及其数值模拟

    Institute of Scientific and Technical Information of China (English)

    王晓辉; 于存贵

    2011-01-01

    Separation flow could be generated in a high-altitude nozzle, in order to study the flow separation on the nozzle performance. A three-dimensional numerical simulation about the separation flow in the high-altitude nozzle of a solid rocket motor (SRM) was conducted. The flow results with different inlet total pressure were obtained by utilizing CFX software. It shows that, due to the separation flow, there are some adverse effects for the stability and thermal protection of the nozzle. The simulation provides a reference of the design of the high-altitude nozzle, also a basis for further study.%大面积比喷管在火箭发动机工作过程中可能产生流动分离的问题,为研究喷管流动分离对喷管性能的影响,利用计算流体力学软件CFX对某固体火箭发动机大面积比喷管内燃气分离流动进行数值模拟.计算出喷管在几种不同入口总压情况下的流场参数分布,显示分离流动会改变燃气内流场流动参数分布,进而会对喷管推力稳定性和热防护性产生不利影响.该研究能为进一步研究大面积比喷管设计提供参考.

  3. Microjet flow control in an ultra-compact serpentine inlet

    Institute of Scientific and Technical Information of China (English)

    Da Xingy; Fan Zhaolin; Fan Jianchao; Zeng Liquan; Rui Wei; Zhou Run

    2015-01-01

    Microjets are used to control the internal flow to improve the performance of an ultra-compact serpentine inlet. A highly offset serpentine inlet with length-to-diameter ratio of 2.5 is designed and static tests are conducted to analyze the internal flow characteristics in terms of pressure recovery, distortion and flow separation. Flow separation is encountered in the second S-turn, and two strong counter-rotating vortices are formed at the aerodynamic interface plane (AIP) face which occupy a quarter of the outlet area and result in severe pressure loss and distortion. A flow control model employing a row of microjets in the second turn is designed based on the internal flow characteristics and simplified CFD simulations. Flow control tests are conducted to verify the control effectiveness and understand the characteristics as a function of inlet throat Mach number, injection mass flow ratio, jet Mach number and momentum coefficient. At all test Mach numbers, microjet flow control (MFC) effectively improves the recovery and reduces the distortion intensity. Between inlet throat Mach number 0.2 and 0.5, the strong flow separation in the second S-turn is suppressed at an optimum jet flow ratio of less than 0.65%, resulting in a maximum improvement of 4% for pressure recovery coefficient and a maximum decrease of 75% for circumferential distortion intensity at cruise. However, in order to suppress the flow separation, the injection rate should retain in an effective range. When the injection rate is higher than this range, the flow is degraded and the distortion contour is changed from 90? circumferential distortion pattern to 180? circumferential distortion pattern. Detailed data analysis shows that this optimum flow ratio depends on inlet throat Mach number and the momentum coefficient affects the control effectiveness in a dual stepping manner.

  4. Microjet flow control in an ultra-compact serpentine inlet

    Directory of Open Access Journals (Sweden)

    Da Xingya

    2015-10-01

    Full Text Available Microjets are used to control the internal flow to improve the performance of an ultra-compact serpentine inlet. A highly offset serpentine inlet with length-to-diameter ratio of 2.5 is designed and static tests are conducted to analyze the internal flow characteristics in terms of pressure recovery, distortion and flow separation. Flow separation is encountered in the second S-turn, and two strong counter-rotating vortices are formed at the aerodynamic interface plane (AIP face which occupy a quarter of the outlet area and result in severe pressure loss and distortion. A flow control model employing a row of microjets in the second turn is designed based on the internal flow characteristics and simplified CFD simulations. Flow control tests are conducted to verify the control effectiveness and understand the characteristics as a function of inlet throat Mach number, injection mass flow ratio, jet Mach number and momentum coefficient. At all test Mach numbers, microjet flow control (MFC effectively improves the recovery and reduces the distortion intensity. Between inlet throat Mach number 0.2 and 0.5, the strong flow separation in the second S-turn is suppressed at an optimum jet flow ratio of less than 0.65%, resulting in a maximum improvement of 4% for pressure recovery coefficient and a maximum decrease of 75% for circumferential distortion intensity at cruise. However, in order to suppress the flow separation, the injection rate should retain in an effective range. When the injection rate is higher than this range, the flow is degraded and the distortion contour is changed from 90° circumferential distortion pattern to 180° circumferential distortion pattern. Detailed data analysis shows that this optimum flow ratio depends on inlet throat Mach number and the momentum coefficient affects the control effectiveness in a dual stepping manner.

  5. The physical environment affects cyanophage communities in British Columbia inlets.

    Science.gov (United States)

    Frederickson, C M; Short, S M; Suttle, C A

    2003-10-01

    Little is known about the natural distribution of viruses that infect the photosynthetically important group of marine prokaryotes, the cyanobacteria. The current investigation reveals that the structure of cyanophage communities is dependent on water column structure. PCR was used to amplify a fragment of the cyanomyovirus gene (g) 20, which codes for the portal vertex protein. Denaturing gradient gel electrophoresis (DGGE) of PCR amplified g20 gene fragments was used to examine variations in cyanophage community structure in three inlets in British Columbia, Canada. Qualitative examination of denaturing gradient gels revealed cyanophage community patterns that reflected the physical structure of the water column as indicated by temperature and salinity. Based on mobility of PCR fragments in the DGGE gels, some cyanophages appeared to be widespread, while others were observed only at specific depths. Cyanophage communities within Salmon Inlet were more related to one another than to communities from either Malaspina Inlet or Pendrell Sound. As well, surface communities in Malaspina Inlet and Pendrell Sound were different when compared to communities at depth. In the same two locations, distinct differences in community composition were observed in communities that coincided with depths of high chlorophyll fluorescence. The observed community shifts over small distances (only a few meters in depth or inlets separated by less than 100 km) support the idea that cyanophage communities separated by small spatial scales develop independently of each other as a result isolation by water column stratification or land mass separation, which may ultimately lead to changes in the distribution or composition of the host community.

  6. The proton therapy nozzles at Samsung Medical Center: A Monte Carlo simulation study using TOPAS

    Science.gov (United States)

    Chung, Kwangzoo; Kim, Jinsung; Kim, Dae-Hyun; Ahn, Sunghwan; Han, Youngyih

    2015-07-01

    To expedite the commissioning process of the proton therapy system at Samsung Medical Center (SMC), we have developed a Monte Carlo simulation model of the proton therapy nozzles by using TOol for PArticle Simulation (TOPAS). At SMC proton therapy center, we have two gantry rooms with different types of nozzles: a multi-purpose nozzle and a dedicated scanning nozzle. Each nozzle has been modeled in detail following the geometry information provided by the manufacturer, Sumitomo Heavy Industries, Ltd. For this purpose, the novel features of TOPAS, such as the time feature or the ridge filter class, have been used, and the appropriate physics models for proton nozzle simulation have been defined. Dosimetric properties, like percent depth dose curve, spreadout Bragg peak (SOBP), and beam spot size, have been simulated and verified against measured beam data. Beyond the Monte Carlo nozzle modeling, we have developed an interface between TOPAS and the treatment planning system (TPS), RayStation. An exported radiotherapy (RT) plan from the TPS is interpreted by using an interface and is then translated into the TOPAS input text. The developed Monte Carlo nozzle model can be used to estimate the non-beam performance, such as the neutron background, of the nozzles. Furthermore, the nozzle model can be used to study the mechanical optimization of the design of the nozzle.

  7. Effects of Nozzle Geometry and Intermittent Injection of Aerodynamic Tab on Supersonic Jet Noise

    Science.gov (United States)

    Araki, Mikiya; Sano, Takayuki; Fukuda, Masayuki; Kojima, Takayuki; Taguchi, Hideyuki; Shiga, Seiichi; Obokata, Tomio

    Effects of the nozzle geometry and intermittent injection of aerodynamic tabs on exhaust noise from a rectangular plug nozzle were investigated experimentally. In JAXA (Japan Aerospace Exploration Agency), a pre-cooled turbojet engine for an HST (Hypersonic transport) is planned. A 1/100-scaled model of the rectangular plug nozzle is manufactured, and the noise reduction performance of aerodynamic tabs, which is small air jet injection from the nozzle wall, was investigated. Compressed air is injected through the rectangular plug nozzle into the atmosphere at the nozzle pressure ratio of 2.7, which corresponds to the take-off condition of the vehicle. Aerodynamic tabs were installed at the sidewall ends, and 4 kinds of round nozzles and 2 kinds of wedge nozzles were applied. Using a high-frequency solenoid valve, intermittent gas injection is also applied. It is shown that, by use of wedge nozzles, the aerodynamic tab mass flow rate, necessary to gain 2.3dB reduction in OASPL (Overall sound pressure level), decreases by 29% when compared with round nozzles. It is also shown that, by use of intermittent injection, the aerodynamic tab mass flow rate, necessary to gain 2.3dB reduction in OASPL, decreases by about 40% when compared with steady injection. By combination of wedge nozzles and intermittent injection, the aerodynamic tab mass flow rate significantly decreases by 57% when compared with the conventional strategy.

  8. The effects of a spray slurry nozzle on copper CMP for reduction in slurry consumption

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Da Sol; Jeong, Hae Do [Pusan National University, Busan (Korea, Republic of); Lee, Hyun Seop [Tongmyong University, Busan (Korea, Republic of)

    2015-12-15

    The environmental impact of semiconductor manufacturing has been a big social problem, like greenhouse gas emission. Chemical mechanical planarization (CMP), a wet process which consumes chemical slurries, seriously impacts environmental sustain ability and cost-effectiveness. This paper demonstrates the superiority of a full-cone spray slurry nozzle to the conventional tube-type slurry nozzle in Cu CMP. It was observed that the spray nozzle made a weak slurry wave at the retaining ring unlike a conventional nozzle, because the slurry was supplied uniformly in broader areas. Experiments were implemented with different slurry flow rates and spray nozzle heights. Spray nozzle performance is controlled by the spray angle and spray height. The process temperature was obtained with an infrared (IR) sensor and an IR thermal imaging camera to investigate the cooling effect of the spray. The results show that the spray nozzle provides a higher Material removal rate (MRR), lower non-uniformity (NU), and lower temperature than the conventional nozzle. Computational fluid dynamics techniques show that the turbulence kinetic energy and slurry velocity of the spray nozzle are much higher than those of the conventional nozzle. Finally, it can be summarized that the spray nozzle plays a significant role in slurry efficiency by theory of Minimum quantity lubrication (MQL).

  9. Static investigation of two STOL nozzle concepts with pitch thrust-vectoring capability

    Science.gov (United States)

    Mason, M. L.; Burley, J. R., II

    1986-01-01

    A static investigation of the internal performance of two short take-off and landing (STOL) nozzle concepts with pitch thrust-vectoring capability has been conducted. An axisymmetric nozzle concept and a nonaxisymmetric nozzle concept were tested at dry and afterburning power settings. The axisymmetric concept consisted of a circular approach duct with a convergent-divergent nozzle. Pitch thrust vectoring was accomplished by vectoring the approach duct without changing the nozzle geometry. The nonaxisymmetric concept consisted of a two dimensional convergent-divergent nozzle. Pitch thrust vectoring was implemented by blocking the nozzle exit and deflecting a door in the lower nozzle flap. The test nozzle pressure ratio was varied up to 10.0, depending on model geometry. Results indicate that both pitch vectoring concepts produced resultant pitch vector angles which were nearly equal to the geometric pitch deflection angles. The axisymmetric nozzle concept had only small thrust losses at the largest pitch deflection angle of 70 deg., but the two-dimensional convergent-divergent nozzle concept had large performance losses at both of the two pitch deflection angles tested, 60 deg. and 70 deg.

  10. Investigation of Thrust and Drag Characteristics of a Plug-type Exhaust Nozzle

    Science.gov (United States)

    Hearth, Donald P; Gorton, Gerald C

    1954-01-01

    An investigation was conducted in the 8- by 6-foot supersonic wind tunnel on the external and internal characteristics of a plug-type exhaust nozzle. Two positions of the center plug, one simulating a convergent nozzle and the other a convergent-divergent nozzle, were investigated. Data were obtained at free-stream Mach numbers of 0.1, 0.6, 1.6, and 2.0 over a pressure-ratio range of 1 to 20 and angles of attack of zero and 8 degrees. Results of this investigation indicated that the plug nozzle had thrust-minus-drag performance over the entire pressure-ratio range comparable with equivalent conventional nozzles. The effect of the exhaust jet on the external aerodynamics was similar to results observed for conventional nozzles. In addition, the thrust characteristics were generally insensitive to external flow and good agreement was noted with data obtained on comparable plug nozzles in quiescent air.

  11. Modelling Morphological Response of Large Tidal Inlet Systems to Sea Level Rise

    NARCIS (Netherlands)

    Dissanayake, P.K.

    2011-01-01

    This dissertation qualitatively investigates the morphodynamic response of a large inlet system to IPCC projected relative sea level rise (RSLR). Adopted numerical approach (Delft3D) used a highly schematised model domain analogous to the Ameland inlet in the Dutch Wadden Sea. Predicted inlet evolut

  12. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Science.gov (United States)

    2010-07-01

    ... Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook Inlet Intrastate Air Quality Control Region (Alaska) consists of the territorial area encompassed by the boundaries... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Cook Inlet Intrastate Air...

  13. A Combined CFD/Characteristic Method for Prediction and Design of Hypersonic Inlet with Nose Bluntness

    Science.gov (United States)

    Gao, Wenzhi; Li, Zhufei; Yang, Jiming

    Leading edge bluntness is widely used in hypersonic inlet design for thermal protection[1]. Detailed research of leading edge bluntness on hypersonic inlet has been concentrated on shock shape correlation[2], boundary layer flow[3], inlet performance[4], etc. It is well known that blunted noses cause detached bow shocks which generate subsonic regions around the noses and entropy layers in the flowfield.

  14. Non-linear dynamics of inlet film thickness during unsteady rolling process

    Science.gov (United States)

    Fu, Kuo; Zang, Yong; Gao, Zhiying; Qin, Qin; Wu, Diping

    2016-05-01

    The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

  15. 78 FR 11094 - Safety Zone; Lake Worth Dredge Operations, Lake Worth Inlet; West Palm Beach, FL

    Science.gov (United States)

    2013-02-15

    ... Guard is establishing a temporary safety zone on Lake Worth Inlet, West Palm Beach, Florida, to provide..., February 20, 2013, dredging operations will be conducted on Lake Worth Inlet in West Palm Beach, Florida... the southwestern corner of Singer Island and then due south across the inlet to Palm Beach...

  16. 78 FR 48314 - Drawbridge Operation Regulation; Milford Haven Inlet, Hudgins, VA

    Science.gov (United States)

    2013-08-08

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Milford Haven Inlet, Hudgins, VA... Bridge (Gwynn's Island) across the Milford Haven Inlet, mile 0.1, at Hudgins, Virginia. The deviation is... Milford Haven Inlet near Hudgins, Virginia. VDOT requested a deviation from the requirement to open on...

  17. 76 FR 24513 - Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse Withdrawal; Florida

    Science.gov (United States)

    2011-05-02

    ... Bureau of Land Management Public Land Order No. 7765; Partial Revocation Jupiter Inlet Lighthouse... Management to continue to be managed as part of the Jupiter Inlet Lighthouse Outstanding Natural Area. DATES... Resource Act of 2008 (43 U.S.C. 1787), which created the Jupiter Inlet Lighthouse Outstanding Natural...

  18. Cooling nozzles characteristics for numerical models of continuous casting

    Directory of Open Access Journals (Sweden)

    R. Pyszko

    2013-10-01

    Full Text Available Modelling the temperature field of a continuously cast strand is an important tool for the process diagnostics. The main preconditions for numerical simulation of the temperature field of the solidifying strand are correct boundary conditions, especially the surface condition in the secondary zone of the caster. The paper deals with techniques of determining the surface condition under cooling nozzles as well as their approximation and implementation into the model algorithm. Techniques used for laboratory measurements of both cold and hot spraying characteristics of water or water-air cooling nozzles are described. The relationship between the cold and hot characteristics was found. Implementation of such a dependence into the model algorithm reduces the duration and cost of laboratory measurements.

  19. Development of Submerged Entry Nozzles that Resist Clogging

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Jeffrey D. Smith; Kent D. Peasle

    2002-10-14

    Accretion formation and the associated clogging of SENs is a major problem for the steel industry leading to decreased strand speed, premature changing of SENs or strand termination and the associated reductions in productivity, consistency, and steel quality. A program to evaluate potentially clog resistance materials was initiated at the University of Missouri-Rolla. The main objective of the research effort was to identify combinations of steelmaking and refractory practices that would yield improved accretion resistance for tundish nozzles and submerged entry nozzles. A number of tasks were identified during the initial kick-off meeting and each was completed with two exceptions, the thermal shock validation and the industrial trials. Not completing these two tasks related to not having access to industrial scale production facilities. Though much of the results and information generated in the project is of proprietary nature.

  20. 3D Reacting Flow Analysis of LANTR Nozzles

    Science.gov (United States)

    Stewart, Mark E. M.; Krivanek, Thomas M.; Hemminger, Joseph A.; Bulman, M. J.

    2006-01-01

    This paper presents performance predictions for LANTR nozzles and the system implications for their use in a manned Mars mission. The LANTR concept is rocket thrust augmentation by injecting Oxygen into the nozzle to combust the Hydrogen exhaust of a Nuclear Thermal Rocket. The performance predictions are based on three-dimensional reacting flow simulations using VULCAN. These simulations explore a range of O2/H2 mixture ratios, injector configurations, and concepts. These performance predictions are used for a trade analysis within a system study for a manned Mars mission. Results indicate that the greatest benefit of LANTR will occur with In-Situ Resource Utilization (ISRU). However, Hydrogen propellant volume reductions may allow greater margins for fitting tanks within the launch vehicle where packaging issues occur.

  1. Modeling parameter influences on MHD swirl combustion nozzle design

    Science.gov (United States)

    Lilley, D. G.; Gupta, A. K.; Busnaina, A. A.

    1982-01-01

    Attention is given to a research project which has the goal to develop a two-stage slagging gasifier-combustor in the form of a high-intensity combustor, taking into account a suitable aerodynamic design of the second stage nozzle which will prevent the separation of the boundary layer as the flow turns from axial to radial direction. The specific objectives of the present investigation are to test the effect of various second-stage nozzle geometries, flow rates, swirl number, and distribution in the first and second stages upon the corresponding flowfield in the second stage. Special emphasis is given to the avoidance of boundary layer separation as the flow turns from axial to radial direction into the MHD disk generator.

  2. Ground Wars

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Kleis

    Political campaigns today are won or lost in the so-called ground war--the strategic deployment of teams of staffers, volunteers, and paid part-timers who work the phones and canvass block by block, house by house, voter by voter. Ground Wars provides an in-depth ethnographic portrait of two...... infrastructures that utilize large databases with detailed individual-level information for targeting voters, and armies of dedicated volunteers and paid part-timers. Nielsen challenges the notion that political communication in America must be tightly scripted, controlled, and conducted by a select coterie...... of professionals. Yet he also quashes the romantic idea that canvassing is a purer form of grassroots politics. In today's political ground wars, Nielsen demonstrates, even the most ordinary-seeming volunteer knocking at your door is backed up by high-tech targeting technologies and party expertise. Ground Wars...

  3. A Novel Method for Borehole Blockage Removal and Experimental Study on a Hydraulic Self-Propelled Nozzle in Underground Coal Mines

    Directory of Open Access Journals (Sweden)

    Zhaolong Ge

    2016-08-01

    Full Text Available When coal bed methane (CBM drainage boreholes cross fractured, soft, or water-swelling strata, they collapse and block frequently. Borehole blockages result in a rapid decrease in CBM extraction ability, which leads to a reduction in CBM output and threatens coal mine safety production. To solve these problems, a novel method that uses a self-propelled water-jet nozzle to dredge blocked boreholes in coal seams has been proposed on the basis of the existing technology. Based on a theoretical analysis of the reason for borehole caving and the theory of blockage removal, we optimized the nozzle inlet pressure and selected an appropriate high-pressure resin pipe. A field experiment on the blockage removal of blocked CBM drainage boreholes using the proposed method was run in the Fengchun coal mine, Qijiang, Chongqing, southwest China. In this field trial, the time spent to unblock a borehole varied between 18.52 and 34.98 min, which is much shorter than using a drilling rig. After blockage removal, the average pure volume of the methane drainage of a single borehole was increased from 0.03 L/min to ~1.91–7.30 L/min, and the methane drainage concentration of a single borehole increased from 5% to ~44%–85%. The extraction effect increased significantly.

  4. Ambipolar ion acceleration in an expanding magnetic nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Longmier, Benjamin W; Carter, Mark D; Cassady, Leonard D; Chancery, William J; Diaz, Franklin R Chang; Glover, Tim W; Ilin, Andrew V; McCaskill, Greg E; Olsen, Chris S; Squire, Jared P [Ad Astra Rocket Company, 141 W. Bay Area Blvd, Webster, TX (United States); Bering, Edgar A III [Department of Physics and Department of Electrical and Computer Engineering, University of Houston, 617 Science and Research Building 1, Houston, TX (United States); Hershkowitz, Noah [Department of Engineering Physics, University of Wisconsin, 1500 Engineering Dr., Madison, WI (United States)

    2011-02-15

    The helicon plasma stage in the Variable Specific Impulse Magnetoplasma Rocket (VASIMR (registered)) VX-200i device was used to characterize an axial plasma potential profile within an expanding magnetic nozzle region of the laboratory based device. The ion acceleration mechanism is identified as an ambipolar electric field produced by an electron pressure gradient, resulting in a local axial ion speed of Mach 4 downstream of the magnetic nozzle. A 20 eV argon ion kinetic energy was measured in the helicon source, which had a peak magnetic field strength of 0.17 T. The helicon plasma source was operated with 25 mg s{sup -1} argon propellant and 30 kW of RF power. The maximum measured values of plasma density and electron temperature within the exhaust plume were 1 x 10{sup 20} m{sup -3} and 9 eV, respectively. The measured plasma density is nearly an order of magnitude larger than previously reported steady-state helicon plasma sources. The exhaust plume also exhibits a 95% to 100% ionization fraction. The size scale and spatial location of the plasma potential structure in the expanding magnetic nozzle region appear to follow the size scale and spatial location of the expanding magnetic field. The thickness of the potential structure was found to be 10{sup 4} to 10{sup 5} {lambda}{sub De} depending on the local electron temperature in the magnetic nozzle, many orders of magnitude larger than typical laboratory double layer structures. The background plasma density and neutral argon pressure were 10{sup 15} m{sup -3} and 2 x 10{sup -5} Torr, respectively, in a 150 m{sup 3} vacuum chamber during operation of the helicon plasma source. The agreement between the measured plasma potential and plasma potential that was calculated from an ambipolar ion acceleration analysis over the bulk of the axial distance where the potential drop was located is a strong confirmation of the ambipolar acceleration process.

  5. Indoor spray measurement of spray drift potential using a spray drift test bench : effect of drift-reducing nozzle types, spray boom height, nozzle spacing and forward speed

    NARCIS (Netherlands)

    Moreno Ruiz, J.R.

    2014-01-01

    In a series of indoor experiments spray drift potential was assessed when spraying over a spray drift testbench with two different driving speeds, 2m/s and 4m/s, two different spray boom heights, 30 cm and 50 cm, and two different nozzle spacing, 25 cm and 50 cm, for six different nozzle types. The

  6. Piezoelectric diffuser/nozzle micropump with double pump chambers

    Institute of Scientific and Technical Information of China (English)

    Wei WANG; Ying ZHANG; Li TIAN; Xiaojie CHEN; Xiaowei LIU

    2008-01-01

    To eliminate check valve fatigue and valve clogging, diffuser/nozzle elements are used for flow rec-tification in a valveless diffuser/nozzle micropump instead of valves. However, the application of this type of micro-pump is restricted because of its pulsating or periodic flow and low pump flux. In this paper, a diffuser/nozzle Si/ Glass micropump with two pump chambers by IC and MEMS technology is designed. The fabrication process requires only one mask and one etch step, so that the fabrication has the advantages of low cost, short proces-sing period, and facilitation of miniaturization. The pump is equipped with a glass cover board so as to conveniently observe the flow status. Pump-chambers and diffuser ele-ments are fabricated by the anisotropic KOH-etch tech-nique on the silicone substrate, and the convex corner is designed to compensate for an anisotropic etch. The driv-ing force of the micropump is produced by the PZT piezo-electric actuator, The pump performance with both actuators actuated in anti- or same-phase mode is also researched. The result indicates that the micropump achieves great performance with the actuators working at anti-phase. This may be because the liquid flows stead-ily, pulse phenomenon is very weak, and the optimal working frequency, pump back pressure, and flow rate are both double that of the pump driven in same-phase.

  7. Exhaust Nozzle Materials Development for the High Speed Civil Transport

    Science.gov (United States)

    Grady, J. E.

    1999-01-01

    The United States has embarked on a national effort to develop the technology necessary to produce a Mach 2.4 High Speed Civil Transport (HSCT) for entry into service by the year 2005. The viability of this aircraft is contingent upon its meeting both economic and environmental requirements. Two engine components have been identified as critical to the environmental acceptability of the HSCT. These include a combustor with significantly lower emissions than are feasible with current technology, and a lightweight exhaust nozzle that meets community noise standards. The Enabling Propulsion Materials (EPM) program will develop the advanced structural materials, materials fabrication processes, structural analysis and life prediction tools for the HSCT combustor and low noise exhaust nozzle. This is being accomplished through the coordinated efforts of the NASA Lewis Research Center, General Electric Aircraft Engines and Pratt & Whitney. The mission of the EPM Exhaust Nozzle Team is to develop and demonstrate this technology by the year 1999 to enable its timely incorporation into HSCT propulsion systems.

  8. Chemical processes in the turbine and exhaust nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Lukachko, S.P.; Waitz, I.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Aero-Environmental Lab.; Miake-Lye, R.C.; Brown, R.C.; Anderson, M.R. [Aerodyne Research, Inc., Billerica, MA (United States); Dawes, W.N. [University Engineering Dept., Cambridge (United Kingdom). Whittle Lab.

    1997-12-31

    The objective is to establish an understanding of primary pollutant, trace species, and aerosol chemical evolution as engine exhaust travels through the nonuniform, unsteady flow fields of the turbine and exhaust nozzle. An understanding of such processes is necessary to provide accurate inputs for plume-wake modeling efforts and is therefore a critical element in an assessment of the atmospheric effects of both current and future aircraft. To perform these studies, a numerical tool was developed combining the calculation of chemical kinetics and one-, two-, or three-dimensional (1-D, 2-D, 3-D) Reynolds-averaged flow equations. Using a chemistry model that includes HO{sub x}, NO{sub y}, SO{sub x}, and CO{sub x} reactions, several 1-D parametric analyses were conducted for the entire turbine and exhaust nozzle flow path of a typical advanced subsonic engine to understand the effects of various flow and chemistry uncertainties on a baseline 1-D result. These calculations were also used to determine parametric criteria for judging 1-D, 2-D, and 3-D modeling requirements as well as to provide information about chemical speciation at the nozzle exit plane. (author) 9 refs.

  9. Thermal analysis of the MC-1 chamber/nozzle

    Science.gov (United States)

    Davis, Darrell

    2001-02-01

    This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the MC-1 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed .

  10. Nozzle Flow with Vibrational Nonequilibrium. Ph.D. Thesis

    Science.gov (United States)

    Landry, John Gary

    1995-01-01

    Flow of nitrogen gas through a converging-diverging nozzle is simulated. The flow is modeled using the Navier-Stokes equations that have been modified for vibrational nonequilibrium. The energy equation is replaced by two equations. One equation accounts for energy effects due to the translational and rotational degrees of freedom, and the other accounts for the affects due to the vibrational degree of freedom. The energy equations are coupled by a relaxation time which measures the time required for the vibrational energy component to equilibrate with the translational and rotational energy components. An improved relaxation time is used in this thesis. The equations are solved numerically using the Steger-Warming flux vector splitting method and the Implicit MacCormack method. The results show that uniform flow is produced outside of the boundary layer. Nonequilibrium exists in both the converging and diverging nozzle sections. The boundary layer region is characterized by a marked increase in translational-rotational temperature. The vibrational temperature remains frozen downstream of the nozzle, except in the boundary layer.

  11. Numerical Investigation of Plasma Detachment in Magnetic Nozzle Experiments

    Science.gov (United States)

    Sankaran, Kamesh; Polzin, Kurt A.

    2008-01-01

    At present there exists no generally accepted theoretical model that provides a consistent physical explanation of plasma detachment from an externally-imposed magnetic nozzle. To make progress towards that end, simulation of plasma flow in the magnetic nozzle of an arcjet experiment is performed using a multidimensional numerical simulation tool that includes theoretical models of the various dispersive and dissipative processes present in the plasma. This is an extension of the simulation tool employed in previous work by Sankaran et al. The aim is to compare the computational results with various proposed magnetic nozzle detachment theories to develop an understanding of the physical mechanisms that cause detachment. An applied magnetic field topology is obtained using a magnetostatic field solver (see Fig. I), and this field is superimposed on the time-dependent magnetic field induced in the plasma to provide a self-consistent field description. The applied magnetic field and model geometry match those found in experiments by Kuriki and Okada. This geometry is modeled because there is a substantial amount of experimental data that can be compared to the computational results, allowing for validation of the model. In addition, comparison of the simulation results with the experimentally obtained plasma parameters will provide insight into the mechanisms that lead to plasma detachment, revealing how they scale with different input parameters. Further studies will focus on modeling literature experiments both for the purpose of additional code validation and to extract physical insight regarding the mechanisms driving detachment.

  12. Thermal Barriers Developed for Solid Rocket Motor Nozzle Joints

    Science.gov (United States)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.

    2000-01-01

    Space shuttle solid rocket motor case assembly joints are sealed with conventional O-ring seals that are shielded from 5500 F combustion gases by thick layers of insulation and by special joint-fill compounds that fill assembly splitlines in the insulation. On a number of occasions, NASA has observed hot gas penetration through defects in the joint-fill compound of several of the rocket nozzle assembly joints. In the current nozzle-to-case joint, NASA has observed penetration of hot combustion gases through the joint-fill compound to the inboard wiper O-ring in one out of seven motors. Although this condition does not threaten motor safety, evidence of hot gas penetration to the wiper O-ring results in extensive reviews before resuming flight. The solid rocket motor manufacturer (Thiokol) approached the NASA Glenn Research Center at Lewis Field about the possibility of applying Glenn's braided fiber preform seal as a thermal barrier to protect the O-ring seals. Glenn and Thiokol are working to improve the nozzle-to-case joint design by implementing a more reliable J-leg design and by using a braided carbon fiber thermal barrier that would resist any hot gases that the J-leg does not block.

  13. Development of Thermal Barriers For Solid Rocket Motor Nozzle Joints

    Science.gov (United States)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.

    2000-01-01

    Joints in the Space Shuttle solid rocket motors are sealed by O-rings to contain combustion gases inside the rocket that reach pressures of up to 900 psi and temperatures of up to 5500 F. To provide protection for the O-rings, the motors are insulated with either phenolic or rubber insulation. Gaps in the joints leading up to the O-rings are filled with polysulfide joint-fill compounds as an additional level of protection. The current RSRM nozzle-to-case joint design incorporating primary, secondary, and wiper O-rings experiences gas paths through the joint-fill compound to the innermost wiper O-ring in about one out of every seven motors. Although this does not pose a safety hazard to the motor, it is an undesirable condition that NASA and rocket manufacturer Thiokol want to eliminate. Each nozzle-to-case joint gas path results in extensive reviews and evaluation before flights can be resumed. Thiokol and NASA Marshall are currently working to improve the nozzle-to-case joint design by implementing a more reliable J-leg design that has been used successfully in the field and igniter joint. They are also planning to incorporate the NASA Glenn braided carbon fiber thermal barrier into the joint. The thermal barrier would act as an additional level of protection for the O-rings and allow the elimination of the joint-fill compound from the joint.

  14. Mechanics and rates of tidal inlet migration: Modeling and application to natural examples

    Science.gov (United States)

    Nienhuis, Jaap H.; Ashton, Andrew D.

    2016-11-01

    Tidal inlets on barrier coasts can migrate alongshore hundreds of meters per year, often presenting great management and engineering challenges. Here we perform model experiments with migrating tidal inlets in Delft3D-SWAN to investigate the mechanics and rates of inlet migration. Model experiments with obliquely approaching waves suggest that tidal inlet migration occurs due to three mechanisms: (1) littoral sediment deposition along the updrift inlet bank, (2) wave-driven sediment transport preferentially eroding the downdrift bank of the inlet, and (3) flood-tide-driven flow preferentially cutting along the downdrift inlet bank because it is less obstructed by flood-tidal delta deposits. To quantify tidal inlet migration, we propose and apply a simple mass balance framework of sediment fluxes around inlets that includes alongshore sediment bypassing and flood-tidal delta deposition. In model experiments, both updrift littoral sediment and the eroded downdrift inlet bank are sediment sources to the growing updrift barrier and the flood-tidal delta, such that tidal inlets can be net sink of up to 150% of the littoral sediment flux. Our mass balance framework demonstrates how, with flood-tidal deltas acting as a littoral sediment sink, migrating tidal inlets can drive erosion of the downdrift barrier beach. Parameterizing model experiments, we propose a predictive model of tidal inlet migration rates based upon the relative momentum flux of the inlet jet and the alongshore radiation stress; we then compare these predicted migration rates to 22 natural tidal inlets along the U.S. East Coast and find good agreement.

  15. Experimental Investigation of Fan Rotor Response to Inlet Swirl Distortion

    OpenAIRE

    Frohnapfel, Dustin Joseph

    2016-01-01

    Next generation aircraft design focuses on highly integrated airframe/engine architectures that exploit advantages in system level efficiency and performance. One such design concept incorporates boundary layer ingestion which locates the turbofan engine inlet near enough to the lifting surface of the aircraft skin that the boundary layer is ingested and reenergized. This process reduces overall aircraft drag and associated required thrust, resulting in fuel savings and decreased emissions;...

  16. Observations and modeling of a tidal inlet dye tracer plume

    Science.gov (United States)

    Feddersen, Falk; Olabarrieta, Maitane; Guza, R. T.; Winters, D.; Raubenheimer, Britt; Elgar, Steve

    2016-10-01

    A 9 km long tracer plume was created by continuously releasing Rhodamine WT dye for 2.2 h during ebb tide within the southern edge of the main tidal channel at New River Inlet, NC on 7 May 2012, with highly obliquely incident waves and alongshore winds. Over 6 h from release, COAWST (coupled ROMS and SWAN, including wave, wind, and tidal forcing) modeled dye compares well with (aerial hyperspectral and in situ) observed dye concentration. Dye first was transported rapidly seaward along the main channel and partially advected across the ebb-tidal shoal until reaching the offshore edge of the shoal. Dye did not eject offshore in an ebb-tidal jet because the obliquely incident breaking waves retarded the inlet-mouth ebb-tidal flow and forced currents along the ebb shoal. The dye plume largely was confined to <4 m depth. Dye was then transported downcoast in the narrow (few 100 m wide) surfzone of the beach bordering the inlet at 0.3 m s-1 driven by wave breaking. Over 6 h, the dye plume is not significantly affected by buoyancy. Observed dye mass balances close indicating all released dye is accounted for. Modeled and observed dye behaviors are qualitatively similar. The model simulates well the evolution of the dye center of mass, lateral spreading, surface area, and maximum concentration, as well as regional ("inlet" and "ocean") dye mass balances. This indicates that the model represents well the dynamics of the ebb-tidal dye plume. Details of the dye transport pathways across the ebb shoal are modeled poorly perhaps owing to low-resolution and smoothed model bathymetry. Wave forcing effects have a large impact on the dye transport.

  17. Starting Processes of High Contraction Ratio Scramjet Inlets

    Science.gov (United States)

    2012-01-01

    lack of thrust production that can lead to terminal flight failure. Between these two regions however lie conditions of great interest. Both started...coated cable of 0.7mm diameter. A brass cylindrical attachment was screwed onto the piston con-rod, with a brass champignon/ mushroom connector...At a given substrate depth x (distance from the wall of the inlet geometry), the temperature can be considered to be constant during the short

  18. Boussinesq Modeling for Inlets, Harbors & Structures (Bouss-2D)

    Science.gov (United States)

    2014-10-27

    longshore and rip currents, wave-current and wave interaction with porous media , wave propagation over vegetated areas, wetlands and marshes, and vessel...circulation in surf and swash zone; wave-current interaction in channels and inlets; generation and impacts of infra- gravity waves on ports and...New structures will be proposed to reduce navigation channel shoaling and decrease vessel influence (e.g., waves, erosion). Ship-to-ship and ship

  19. Technology Review of Modern Gas Turbine Inlet Filtration Systems

    OpenAIRE

    2012-01-01

    An inlet air filtration system is essential for the successful operation of a gas turbine. The filtration system protects the gas turbine from harmful debris in the ambient air, which can lead to issues such as FOD, erosion, fouling, and corrosion. These issues if not addressed will result in a shorter operational life and reduced performance of the gas turbine. Modern day filtration systems are comprised of multiple filtration stages. Each stage is selected based on the local operating envir...

  20. Thermography of the New River Inlet plume and nearshore currents

    Science.gov (United States)

    Chickadel, C.; Jessup, A.

    2012-12-01

    As part of the DARLA and RIVET experiments, thermal imaging systems mounted on a tower and in an airplane captured water flow in the New River Inlet, NC, USA. Kilometer-scale, airborne thermal imagery of the inlet details the ebb flow of the estuarine plume water mixing with ocean water. Multiple fronts, corresponding to the preferred channels through the ebb tidal delta, are imaged in the aerial data. A series of internal fronts suggest discreet sources of the tidal plume that vary with time. Focused thermal measurements made from a tower on the south side of the inlet viewed an area within a radius of a few hundred meters. Sub-meter resolution video from the tower revealed fine-scale flow features and the interaction of tidal exchange and wave-forced surfzone currents. Using the tower and airborne thermal image data we plan to provide geophysical information to compare with numerical models and in situ measurements made by other investigators. From the overflights, we will map the spatial and temporal extent of the estuarine plume to correlate with tidal phase and local wind conditions. From the tower data, we will investigate the structure of the nearshore flow using a thermal particle image velocimetry (PIV) technique, which is based on tracking motion of the surface temperature patterns. Long term variability of the mean and turbulent two-dimensional PIV currents will be correlated to local wave, tidal, and wind forcing parameters.

  1. JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

    Directory of Open Access Journals (Sweden)

    Jiří Pečinka

    2017-02-01

    Full Text Available Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion that might appear at the inlet of a gas turbine engine (GTE during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

  2. Data base for the prediction of inlet external drag

    Science.gov (United States)

    Mcmillan, O. J.; Perkins, E. W.; Perkins, S. C., Jr.

    1980-01-01

    Results are presented from a study to define and evaluate the data base for predicting an airframe/propulsion system interference effect shown to be of considerable importance, inlet external drag. The study is focused on supersonic tactical aircraft with highly integrated jet propulsion systems, although some information is included for supersonic strategic aircraft and for transport aircraft designed for high subsonic or low supersonic cruise. The data base for inlet external drag is considered to consist of the theoretical and empirical prediction methods as well as the experimental data identified in an extensive literature search. The state of the art in the subsonic and transonic speed regimes is evaluated. The experimental data base is organized and presented in a series of tables in which the test article, the quantities measured and the ranges of test conditions covered are described for each set of data; in this way, the breadth of coverage and gaps in the existing experimental data are evident. Prediction methods are categorized by method of solution, type of inlet and speed range to which they apply, major features are given, and their accuracy is assessed by means of comparison to experimental data.

  3. Exchange inlet optimization by genetic algorithm for improved RBCC performance

    Science.gov (United States)

    Chorkawy, G.; Etele, J.

    2017-09-01

    A genetic algorithm based on real parameter representation using a variable selection pressure and variable probability of mutation is used to optimize an annular air breathing rocket inlet called the Exchange Inlet. A rapid and accurate design method which provides estimates for air breathing, mixing, and isentropic flow performance is used as the engine of the optimization routine. Comparison to detailed numerical simulations show that the design method yields desired exit Mach numbers to within approximately 1% over 75% of the annular exit area and predicts entrained air massflows to between 1% and 9% of numerically simulated values depending on the flight condition. Optimum designs are shown to be obtained within approximately 8000 fitness function evaluations in a search space on the order of 106. The method is also shown to be able to identify beneficial values for particular alleles when they exist while showing the ability to handle cases where physical and aphysical designs co-exist at particular values of a subset of alleles within a gene. For an air breathing engine based on a hydrogen fuelled rocket an exchange inlet is designed which yields a predicted air entrainment ratio within 95% of the theoretical maximum.

  4. Numerical study of unsteady starting characteristics of a hypersonic inlet

    Institute of Scientific and Technical Information of China (English)

    Wang Weixing; Guo Rongwei

    2013-01-01

    The impulse and self starting characteristics of a mixed-compression hypersonic inlet designed at Mach number of 6.5 are studied by applying the unsteady computational fluid dynamics (CFD) method.The full Navier-Stokes equations are solved with the assumption of viscous perfect gas model,and the shear-stress transport (SST) k-ω two-equation Reynolds averaged NavierStokes (RANS) model is used for turbulence modeling.Results indicate that during impulse starting,the flow field is divided into three zones with different aerodynamic parameters by primary shock and upstream-facing shock.The separation bubble on the shoulder of ramp undergoes a generating,growing,swallowing and disappearing process in sequence.But a separation bubble at the entrance of inlet exists until the freestream velocity is accelerated to the starting Mach number during self starting.The mass flux distribution of flow field is non-uniform because of the interaction between shock and boundary layer,so that the mass flow rate at throat is unsteady during impulse starting.The duration of impulse starting process increases almost linearly with the decrease of fleestream Mach number but rises abruptly when the freestream Mach number approaches the starting Mach number.The accelerating performance of booster almost has no influence on the self starting ability of hypersonic inlet.

  5. Air Motion and Thermal Environment in Pig Housing Facilities with Diffuse Inlet

    DEFF Research Database (Denmark)

    Jacobsen, Lis

    A ventilation system with ambient air supply through diffuse ceiling used in pig production facilities is presented. The climatic conditions were examined both experimentally and numerically in an full scale experimental room and the inlet boundary conditions of the diffuse inlet were examined...... of thermal comfort in terms of the operative temperature of the occupational zone. A model of the boundary condition of the diffuse inlet is necessary because the inlet is a conglomeration of an inlet and a wall boundary condition. Two methods of modelling can be chosen, a model based on the determination...

  6. Experimental investigation and exergy analysis of the performance of a counter flow Ranque-Hilsch vortex tube with regard to nozzle cross-section areas

    Energy Technology Data Exchange (ETDEWEB)

    Dincer, K.; Avci, A.; Berber, A. [Dept. of Mechanical Eng., Fac. of Eng. and Architecture, Selcuk Univ., Selcuklu, Konya (Turkey); Baskaya, S. [Dept. of Mechanical Eng., Fac. of Eng. and Architecture, Gazi Univ., Maltepe, Ankara (Turkey)

    2010-08-15

    Exergy analysis and performance of a Ranque-Hilsch Vortex Tube (RHVT) with various nozzle cross-section areas (NCSA = 3 x 3, 4 x 4, 5 x 5 mm{sup 2}) were determined under inlet pressures (P{sub i}) of 260, 300 kPa (absolute) pressurized air. The maximum difference in the temperatures of hot output and cold output streams was obtained for NCSA = 3 x 3 mm{sup 2}. The total inlet exergy (sum E{sub i}), total outlet exergy (sum E{sub O}), total lost exergy (sum E{sub Lost}) and exergy efficiency ({eta}, %) were calculated. It was determined that the exergy efficiency of the system, varied between 1% and 39%, and the highest exergy efficiency was obtained for NCSA = 3 x 3 mm{sup 2}. The exergy efficiency strongly depends on the level of P{sub i}, {xi} and v{sub cold}. Variation of the exergy efficiency decreased with decreasing P{sub i}, {xi}, v{sub cold} and the highest and lowest exergy efficiencies were found when the values of P{sub i}, {xi}, v{sub cold} reached maximum and minimum levels, respectively. (author)

  7. CFD-Based Design Optimization Tool Developed for Subsonic Inlet

    Science.gov (United States)

    1995-01-01

    The traditional approach to the design of engine inlets for commercial transport aircraft is a tedious process that ends with a less-than-optimum design. With the advent of high-speed computers and the availability of more accurate and reliable computational fluid dynamics (CFD) solvers, numerical optimization processes can effectively be used to design an aerodynamic inlet lip that enhances engine performance. The designers' experience at Boeing Corporation showed that for a peak Mach number on the inlet surface beyond some upper limit, the performance of the engine degrades excessively. Thus, our objective was to optimize efficiency (minimize the peak Mach number) at maximum cruise without compromising performance at other operating conditions. Using a CFD code NPARC, the NASA Lewis Research Center, in collaboration with Boeing, developed an integrated procedure at Lewis to find the optimum shape of a subsonic inlet lip and a numerical optimization code, ADS. We used a GRAPE-based three-dimensional grid generator to help automate the optimization procedure. The inlet lip shape at the crown and the keel was described as a superellipse, and the superellipse exponents and radii ratios were considered as design variables. Three operating conditions: cruise, takeoff, and rolling takeoff, were considered in this study. Three-dimensional Euler computations were carried out to obtain the flow field. At the initial design, the peak Mach numbers for maximum cruise, takeoff, and rolling takeoff conditions were 0.88, 1.772, and 1.61, respectively. The acceptable upper limits on the takeoff and rolling takeoff Mach numbers were 1.55 and 1.45. Since the initial design provided by Boeing was found to be optimum with respect to the maximum cruise condition, the sum of the peak Mach numbers at takeoff and rolling takeoff were minimized in the current study while the maximum cruise Mach number was constrained to be close to that at the existing design. With this objective, the

  8. Plastic Limit Load Analysis of Cylindrical Pressure Vessels with Different Nozzle Inclination

    Science.gov (United States)

    Prakash, Anupam; Raval, Harit Kishorchandra; Gandhi, Anish; Pawar, Dipak Bapu

    2016-04-01

    Sudden change in geometry of pressure vessel due to nozzle cutout, leads to local stress concentration and deformation, decreasing its strength. Elastic plastic analysis of cylindrical pressure vessels with different inclination angles of nozzle is important to estimate plastic limit load. In the present study, cylindrical pressure vessels with combined inclination of nozzles (i.e. in longitudinal and radial plane) are considered for elastic plastic limit load analysis. Three dimensional static nonlinear finite element analyses of cylindrical pressure vessels with nozzle are performed for incremental pressure loading. The von Mises stress distribution on pressure vessel shows higher stress zones at shell-nozzle junction. Approximate plastic limit load is obtained by twice elastic slope method. Variation in limit pressure with different combined inclination angle of nozzle is analyzed and found to be distinct in nature. Reported results can be helpful in optimizing pressure vessel design.

  9. Development of automated nondestructive inspection system for BMI nozzles in nuclear vessel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joon Soo; Lee, Won Kun; Han, Won Jin; Lee, Sun Ho; Seong, Un Hak [Doosan Heavy Industries and Construction Co., Ltd., Changwon (Korea, Republic of)

    2013-02-15

    BMI nozzles in bottom head of the nuclear vessel are one of major components in nuclear power plants. The BMI nozzles have high possibility to generate PWSCC(primary water stress corrosion crack) according to recent foreign case although operation temperature is lower then the upper head of the nuclear vessel. Thus, nondestructive inspection of the BMI nozzles is required. But, inspection of BMI nozzles is not easy since the BMI nozzles placed in high radiated area and inside the nozzles filled with boric acid. Thus, in this study, a TOFD transducer for inspection of BMI and automated scanner system with water were developed. Also, validation of performance of the developed transducer and system are performed using specimens with artificial defects.

  10. Effect of Nozzle Material on Downstream Lateral Injection Cold Spray Performance

    Science.gov (United States)

    MacDonald, D.; Leblanc-Robert, S.; Fernández, R.; Farjam, A.; Jodoin, B.

    2016-08-01

    In cold gas dynamic spraying, the gas nature, process stagnation pressure and temperature, and the standoff distance are known to be important parameters that affect the deposition efficiency and coating quality. This investigation attempts to elucidate the effect of nozzle material on coatings produced using a downstream lateral injection cold spray system. Through experimentation, it is shown that the nozzle material has a substantial effect on deposition efficiency and particle velocity. It is proposed that the effects are related to complex interaction between the particles and the internal nozzle walls. The results obtained lead to the conclusion that during the particle/nozzle wall contact, a nozzle with higher thermal diffusivity transfers more heat to the particles. This heat transfer results in lower critical velocities and therefore higher deposition efficiencies, despite a noticeable reduction of particle velocities which is also attributed to particle-nozzle interactions.

  11. Simulation of Cold Flow in a Truncated Ideal Nozzle with Film Cooling

    Science.gov (United States)

    Braman, K. E.; Ruf, J. H.

    2015-01-01

    Flow transients during rocket start-up and shut-down can lead to significant side loads on rocket nozzles. The capability to estimate these side loads computationally can streamline the nozzle design process. Towards this goal, the flow in a truncated ideal contour (TIC) nozzle has been simulated using RANS and URANS for a range of nozzle pressure ratios (NPRs) aimed to match a series of cold flow experiments performed at the NASA MSFC Nozzle Test Facility. These simulations were performed with varying turbulence model choices and for four approximations of the supersonic film injection geometry, each of which was created with a different simplification of the test article geometry. The results show that although a reasonable match to experiment can be obtained with varying levels of geometric fidelity, the modeling choices made do not fully represent the physics of flow separation in a TIC nozzle with film cooling.

  12. Static internal performance including thrust vectoring and reversing of two-dimensional convergent-divergent nozzles

    Science.gov (United States)

    Re, R. J.; Leavitt, L. D.

    1984-01-01

    The effects of geometric design parameters on two dimensional convergent-divergent nozzles were investigated at nozzle pressure ratios up to 12 in the static test facility. Forward flight (dry and afterburning power settings), vectored-thrust (afterburning power setting), and reverse-thrust (dry power setting) nozzles were investigated. The nozzles had thrust vector angles from 0 deg to 20.26 deg, throat aspect ratios of 3.696 to 7.612, throat radii from sharp to 2.738 cm, expansion ratios from 1.089 to 1.797, and various sidewall lengths. The results indicate that unvectored two dimensional convergent-divergent nozzles have static internal performance comparable to axisymmetric nozzles with similar expansion ratios.

  13. Methodology for the Design of Streamline-Traced External-Compression Supersonic Inlets

    Science.gov (United States)

    Slater, John W.

    2014-01-01

    A design methodology based on streamline-tracing is discussed for the design of external-compression, supersonic inlets for flight below Mach 2.0. The methodology establishes a supersonic compression surface and capture cross-section by tracing streamlines through an axisymmetric Busemann flowfield. The compression system of shock and Mach waves is altered through modifications to the leading edge and shoulder of the compression surface. An external terminal shock is established to create subsonic flow which is diffused in the subsonic diffuser. The design methodology was implemented into the SUPIN inlet design tool. SUPIN uses specified design factors to design the inlets and computes the inlet performance, which includes the flow rates, total pressure recovery, and wave drag. A design study was conducted using SUPIN and the Wind-US computational fluid dynamics code to design and analyze the properties of two streamline-traced, external-compression (STEX) supersonic inlets for Mach 1.6 freestream conditions. The STEX inlets were compared to axisymmetric pitot, two-dimensional, and axisymmetric spike inlets. The STEX inlets had slightly lower total pressure recovery and higher levels of total pressure distortion than the axisymmetric spike inlet. The cowl wave drag coefficients of the STEX inlets were 20% of those for the axisymmetric spike inlet. The STEX inlets had external sound pressures that were 37% of those of the axisymmetric spike inlet, which may result in lower adverse sonic boom characteristics. The flexibility of the shape of the capture cross-section may result in benefits for the integration of STEX inlets with aircraft.

  14. Effects of varying podded nacelle-nozzle installations on transonic aeropropulsive characteristics of a supersonic fighter aircraft

    Science.gov (United States)

    Capone, F. J.; Reubush, D. E.

    1983-01-01

    The aeropropulsive characteristics of an advanced twin engine fighter designed for supersonic cruise was investigated in the 16 foot Transonic Tunnel. The performance characteristics of advanced nonaxisymmetric nozzles installed in various nacelle locations, the effects of thrust induced forces on overall aircraft aerodynamics, the trim characteristics, and the thrust reverser performance were evaluated. The major model variables included nozzle power setting; nozzle duct aspect ratio; forward, mid, and aft nacelle axial locations; inboard and outboard underwing nacelle locations; and underwing and overwing nacelle locations. Thrust vectoring exhaust nozzle configurations included a wedge nozzle, a two dimensional convergent divergent nozzle, and a single expansion ramp nozzle, each with deflection angles up to 30 deg. In addition to the nonaxisymmetric nozzles, an axisymmetric nozzle installation was also tested. The use of a canard for trim was also assessed.

  15. The Effect of Fuel Injector Nozzle Configuration on JP-8 Sprays at Diesel Engine Conditions

    Science.gov (United States)

    2014-10-01

    The Effect of Fuel Injector Nozzle Configuration on JP-8 Sprays at Diesel Engine Conditions by Matthew Kurman, Luis Bravo, Chol-Bum Kweon...Fuel Injector Nozzle Configuration on JP-8 Sprays at Diesel Engine Conditions Matthew Kurman, Luis Bravo, and Chol-Bum Kweon Vehicle Technology...March 2014 4. TITLE AND SUBTITLE The Effect of Fuel Injector Nozzle Configuration on JP-8 Sprays at Diesel Engine Conditions 5a. CONTRACT NUMBER 5b

  16. Flow visualization and interpretation of visualization data for deflected thrust V/STOL nozzles

    Science.gov (United States)

    Kao, H. C.; Burstadt, P. L.; Johns, A. L.

    1984-01-01

    Flow visualization studies were made for four deflected thrust nozzle models at subsonic speeds. Based on topological rules and the assumption that observed streaks constitute continuous vector fields, available visualization pictures are interpreted and flow patterns on interior surfaces of the nozzles are synthesized. In particular, three dimensional flow structure and separations are discussed. From the synthesized patterns, the overall features of the flow field in a given nozzle can be approximately perceived. Previously announced in STAR as N84-14147

  17. Diffusive self-ignition of hydrogen upon efflux from a nozzle array

    Science.gov (United States)

    Golub, V. V.; Bazhenova, T. V.; Laskin, I. N.; Semin, N. V.

    2009-03-01

    It is experimentally demonstrated that the efflux of hydrogen at a high pressure into air via a nozzle array is accompanied by the interaction of jets, which results in the conditions for self-ignition at a nozzle diameter below the values for which self-ignition is possible in a single jet. Conditions for the safe efflux of hydrogen via a nozzle array from a reservoir at a pressure of 400 bar (and below) are established.

  18. Non-local electron energy probability function in a plasma expanding along a magnetic nozzle.

    Directory of Open Access Journals (Sweden)

    Roderick William Boswell

    2015-03-01

    Full Text Available Electron energy probability functions (eepfs have been measured along the axis of low pressure plasma expanding in a magnetic nozzle. The eepf at the maximum magnetic field of the nozzle shows a depleted tail commencing at an energy corresponding to the measured potential drop in the magnetic nozzle. The eepfs measured along the axis demonstrate that the potential and kinetic energies of the electrons are conserved and confirm the non-local collisionless kinetics of the electron dynamics.

  19. Parametric investigation of single-expansion-ramp nozzles at Mach numbers from 0.60 to 1.20

    Science.gov (United States)

    Capone, Francis J.; Re, Richard J.; Bare, E. Ann

    1992-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of varying six nozzle geometric parameters on the internal and aeropropulsive performance characteristics of single-expansion-ramp nozzles. This investigation was conducted at Mach numbers from 0.60 to 1.20, nozzle pressure ratios from 1.5 to 12, and angles of attack of 0 deg +/- 6 deg. Maximum aeropropulsive performance at a particular Mach number was highly dependent on the operating nozzle pressure ratio. For example, as the nozzle upper ramp length or angle increased, some nozzles had higher performance at a Mach number of 0.90 because of the nozzle design pressure was the same as the operating pressure ratio. Thus, selection of the various nozzle geometric parameters should be based on the mission requirements of the aircraft. A combination of large upper ramp and large lower flap boattail angles produced greater nozzle drag coefficients at Mach number greater than 0.80, primarily from shock-induced separation on the lower flap of the nozzle. A static conditions, the convergent nozzle had high and nearly constant values of resultant thrust ratio over the entire range of nozzle pressure ratios tested. However, these nozzles had much lower aeropropulsive performance than the convergent-divergent nozzle at Mach number greater than 0.60.

  20. An Interactive Method of Characteristics Java Applet to Design and Analyze Supersonic Aircraft Nozzles

    Science.gov (United States)

    Benson, Thomas J.

    2014-01-01

    The Method of Characteristics (MOC) is a classic technique for designing supersonic nozzles. An interactive computer program using MOC has been developed to allow engineers to design and analyze supersonic nozzle flow fields. The program calculates the internal flow for many classic designs, such as a supersonic wind tunnel nozzle, an ideal 2D or axisymmetric nozzle, or a variety of plug nozzles. The program also calculates the plume flow produced by the nozzle and the external flow leading to the nozzle exit. The program can be used to assess the interactions between the internal, external and plume flows. By proper design and operation of the nozzle, it may be possible to lessen the strength of the sonic boom produced at the rear of supersonic aircraft. The program can also calculate non-ideal nozzles, such as simple cone flows, to determine flow divergence and nonuniformities at the exit, and its effect on the plume shape. The computer program is written in Java and is provided as free-ware from the NASA Glenn central software server.

  1. Interior flow and near-nozzle spray development in a marine-engine diesel fuel injector

    Science.gov (United States)

    Hult, J.; Simmank, P.; Matlok, S.; Mayer, S.; Falgout, Z.; Linne, M.

    2016-04-01

    A consolidated effort at optically characterising flow patterns, in-nozzle cavitation, and near-nozzle jet structure of a marine diesel fuel injector is presented. A combination of several optical techniques was employed to fully transparent injector models, compound metal-glass and full metal injectors. They were all based on a common real-scale dual nozzle hole geometry for a marine two-stroke diesel engine. In a stationary flow rig, flow velocities in the sac-volume and nozzle holes were measured using PIV, and in-nozzle cavitation visualized using high-resolution shadowgraphs. The effect of varying cavitation number was studied and results compared to CFD predictions. In-nozzle cavitation and near-nozzle jet structure during transient operation were visualized simultaneously, using high-speed imaging in an atmospheric pressure spray rig. Near-nozzle spray formation was investigated using ballistic imaging. Finally, the injector geometry was tested on a full-scale marine diesel engine, where the dynamics of near-nozzle jet development was visualized using high-speed shadowgraphy. The range of studies focused on a single common geometry allows a comprehensive survey of phenomena ranging from first inception of cavitation under well-controlled flow conditions to fuel jet structure at real engine conditions.

  2. Direct Numerical Simulation of Hypersonic Turbulent Boundary Layer inside an Axisymmetric Nozzle

    Science.gov (United States)

    Huang, Junji; Zhang, Chao; Duan, Lian; Choudhari, Meelan M.

    2017-01-01

    As a first step toward a study of acoustic disturbance field within a conventional, hypersonic wind tunnel, direct numerical simulations (DNS) of a Mach 6 turbulent boundary layer on the inner wall of a straight axisymmetric nozzle are conducted and the results are compared with those for a flat plate. The DNS results for a nozzle radius to boundary-layer thickness ratio of 5:5 show that the turbulence statistics of the nozzle-wall boundary layer are nearly unaffected by the transverse curvature of the nozzle wall. Before the acoustic waves emanating from different parts of the nozzle surface can interfere with each other and undergo reflections from adjacent portions of the nozzle surface, the rms pressure fluctuation beyond the boundary layer edge increases toward the nozzle axis, apparently due to a focusing effect inside the axisymmetric configuration. Spectral analysis of pressure fluctuations at both the wall and the freestream indicates a similar distribution of energy content for both the nozzle and the flat plate, with the peak of the premultiplied frequency spectrum at a frequency of [(omega)(delta)]/U(sub infinity) approximately 6.0 inside the free stream and at [(omega)(delta)]/U(sub infinity) approximately 2.0 along the wall. The present results provide the basis for follow-on simulations involving reverberation effects inside the nozzle.

  3. Design and development of SiC/(W,Ti)C gradient ceramic nozzle

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The idea of functionally gradient material (FGM) theory was used to design ceramic nozzle based on the erosion wear behaviors of the ceramic nozzles and the out- standing properties of FGM. The purpose is to reduce the tensile stress at the entry region of the nozzle during sand blasting processes. The design theory and methods of gradient ceramic nozzle were proposed. The physical, micromechanical, and composition distribution models of gradient ceramic nozzle were established. The optimum composition distribution of the gradient ceramic nozzle material was determined from the solution of the multi-objective optimization calculation by constructing the models of the composition distribution versus the structural in- tegrity of the compact in fabricating process. Results showed that compressive residual stresses appeared at the entry area of the gradient ceramic nozzle. The optimized component distribution exponent p is 0.5. An SiC/(W,Ti)C gradient ce- ramic nozzle material was synthesized by hot-pressing according to the design result. Results showed that the surface Vickers hardness of the FGM-1 gradient ceramic nozzle materials was greatly improved in comparison with that of the other layers.

  4. Injector Nozzle Flow Model and Its Effects on the Calculations of High Pressure Sprays

    Institute of Scientific and Technical Information of China (English)

    WEI Ming-rui; LIU Yong-chang; WEN Hua; ZHANG Yue-heng

    2004-01-01

    This paper discusses the flowing process inside a nozzle, especially the formation mechanism of cavitations within the nozzle and puts forward a nozzle flow model, which takes account of the injection conditions and nozzle geometry. By the model being implemented to the KIVA codes, the spray characteristics (e.g., spray penetration and cone angle) of diesel and dimethyl ether (DME) are simulated. The comparisons between the computational and experimental results are performed, which show that the liquid spray characteristics could be more truly demonstrated by considering the existence of the cavitations.

  5. Formation of Vortex Structures in the Prenozzle Space of an Engine with a Vectorable Thrust Nozzle

    Science.gov (United States)

    Volkov, K. N.; Emel'yanov, V. N.; Denisikhin, S. V.

    2016-05-01

    A numerical simulation of the hydrodynamic effects arising in the process of work of the vectorable thrust nozzle of a solid-propellant rocket engine has been performed. The fields of the flows of combustion products in the channel of a charge, the prenozzle space, and the nozzle unit were calculated for different angles of vectoring of the nozzle. The distributions of the gasdynamic parameters of the flow of combustion products in the prenozzle space, corresponding to their efflux from the cylindrical and star-shaped channels of charges, were compared. The formation of a vortex flow in the neighborhood of the back cover of the nozzle was considered.

  6. Free-jet acoustic investigation of high-radius-ratio coannular plug nozzles

    Science.gov (United States)

    Knott, P. R.; Janardan, B. A.; Majjigi, R. K.; Bhutiani, P. K.; Vogt, P. G.

    1984-01-01

    The experimental and analytical results of a scale model simulated flight acoustic exploratory investigation of high radius ratio coannular plug nozzles with inverted velocity and temperature profiles are summarized. Six coannular plug nozzle configurations and a baseline convergent conical nozzle were tested for simulated flight acoustic evaluation. The nozzles were tested over a range of test conditions that are typical of a Variable Cycle Engine for application to advanced high speed aircraft. It was found that in simulate flight, the high radius ratio coannular plug nozzles maintain their jet noise and shock noise reduction features previously observed in static testing. The presence of nozzle bypass struts will not significantly affect the acousticn noise reduction features of a General Electric type nozzle design. A unique coannular plug nozzle flight acoustic spectral prediction method was identified and found to predict the measured results quite well. Special laser velocimeter and acoustic measurements were performed which have given new insights into the jet and shock noise reduction mechanisms of coannular plug nozzles with regard to identifying further benificial research efforts.

  7. Design and development of SiC/(W, Ti)C gradient ceramic nozzle

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The idea of functionally gradient material (FGM) theory was used to design ceramic nozzle based on the erosion wear behaviors of the ceramic nozzles and the outstanding properties of FGM. The purpose is to reduce the tensile stress at the entry region of the nozzle during sand blasting processes. The design theory and methods of gradient ceramic nozzle were proposed. The physical, micromechanical, and composition distribution models of gradient ceramic nozzle were established. The optimum composition distribution of the gradient ceramic nozzle material was determined from the solution of the multi-objective optimization calculation by constructing the models of the composition distribution versus the structural integrity of the compact in fabricating process. Results showed that compressive residual stresses appeared at the entry area of the gradient ceramic nozzle. The optimized component distribution exponent p is 0.5. An SiC/(W,Ti)C gradient ceramic nozzle material was synthesized by hot-pressing according to the design result. Results showed that the surface Vickers hardness of the FGM-1 gradient ceramic nozzle materials was greatly improved in comparison with that of the other layers.

  8. Comparison of CFD Simulations with Experimental Measurements of Nozzle Clogging in Continuous Casting of Steels

    Science.gov (United States)

    Mohammadi-Ghaleni, Mahdi; Asle Zaeem, Mohsen; Smith, Jeffrey D.; O'Malley, Ronald

    2016-12-01

    Measurements of clog deposit thickness on the interior surfaces of a commercial continuous casting nozzle are compared with computational fluid dynamics (CFD) predictions of melt flow patterns and particle-wall interactions to identify the mechanisms of nozzle clogging. A submerged entry nozzle received from industry was encased in epoxy and carefully sectioned to allow measurement of the deposit thickness on the internal surfaces of the nozzle. CFD simulations of melt flow patterns and particle behavior inside the nozzle were performed by combining the Eulerian-Lagrangian approach and detached eddy simulation turbulent model, matching the geometry and operating conditions of the industrial test. The CFD results indicated that convergent areas of the interior cross section of the nozzle increased the velocity and turbulence of the flowing steel inside the nozzle and decreased the clog deposit thickness locally in these areas. CFD simulations also predicted a higher rate of attachment of particles in the divergent area between two convergent sections of the nozzle, which matched the observations made in the industrial nozzle measurements.

  9. Numerical Investigation of Jet Noise Prediction in Exhaust Nozzle by Passive Control Techniques

    Directory of Open Access Journals (Sweden)

    Alagu sundaram.A

    2015-05-01

    Full Text Available The project mainly focuses on the reduction of jet noise emission in the exhaust nozzle of TURBOFAN ENGINES. Reduction of noise in the exhaust system is done by attaching chevrons with particular parameters in the nozzle exit. Numerical investigations have been carried out on chevron nozzles to assess the importance of chevron parameters such as the number of chevrons like (chevron count, chevron penetration and the mixing characteristics of co flow jet. Chevron count is the pertinent parameter for noise reduction at low nozzle pressure ratios, whereas at high nozzle pressure ratios, chevron penetration is crucial. The results illustrate that by careful selection of chevron parameters substantial noise reduction can be achieved. The sound pressure level (SPL can be calculated from that we determined the noise level at nozzle exit section. After assessing the chevron parameters we are going to modify the chevron shapes in order to get maximum noise reduction along with very negligible thrust loss. Modification of chevron is based on aspect of increasing the mixing of cold jet and the hot jet in order to decrease the noise emission. ANSYS-Fluent is a commercial CFD code which will be used for performing the simulation and the simulation configuration contains three different velocities (100,150,200 with two different nozzle model(plain & chevron nozzle. The simulation results are evaluated to find out nozzle noise level in the engine exhaust system.

  10. Numerical analysis of Chevron nozzle effects on performance of the supersonic ejector-diffuser system

    Science.gov (United States)

    Kong, Fanshi; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

    2013-10-01

    The supersonic nozzle is the most important device of an ejector-diffuser system. The best operation condition and optimal structure of supersonic nozzle are hardly known due to the complicated turbulent mixing, compressibility effects and even flow unsteadiness which are generated around the nozzle extent. In the present study, the primary stream nozzle was redesigned using convergent nozzle to activate the shear actions between the primary and secondary streams, by means of longitudinal vortices generated between the Chevron lobes. Exactly same geometrical model of ejector-diffuser system was created to validate the results of experimental data. The operation characteristics of the ejector system were compared between Chevron nozzle and conventional convergent nozzle for the primary stream. A CFD method has been applied to simulate the supersonic flows and shock waves inside the ejector. It is observed that the flow structure and shock system were changed and primary numerical analysis results show that the Chevron nozzle achieve a positive effect on the supersonic ejector-diffuser system performance. The ejector with Chevron nozzle can entrain more secondary stream with less primary stream mass flow rate.

  11. Transonic Investigation of Two-Dimensional Nozzles Designed for Supersonic Cruise

    Science.gov (United States)

    Capone, Francis J.; Deere, Karen A.

    2015-01-01

    An experimental and computational investigation has been conducted to determine the off-design uninstalled drag characteristics of a two-dimensional convergent-divergent nozzle designed for a supersonic cruise civil transport. The overall objectives were to: (1) determine the effects of nozzle external flap curvature and sidewall boattail variations on boattail drag; (2) develop an experimental data base for 2D nozzles with long divergent flaps and small boattail angles and (3) provide data for correlating computational fluid dynamic predictions of nozzle boattail drag. The experimental investigation was conducted in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.80 to 1.20 at nozzle pressure ratios up to 9. Three-dimensional simulations of nozzle performance were obtained with the computational fluid dynamics code PAB3D using turbulence closure and nonlinear Reynolds stress modeling. The results of this investigation indicate that excellent correlation between experimental and predicted results was obtained for the nozzle with a moderate amount of boattail curvature. The nozzle with an external flap having a sharp shoulder (no curvature) had the lowest nozzle pressure drag. At a Mach number of 1.2, sidewall pressure drag doubled as sidewall boattail angle was increased from 4deg to 8deg. Reducing the height of the sidewall caused large decreases in both the sidewall and flap pressure drags. Summary

  12. Static internal performance of a two-dimensional convergent-divergent nozzle with thrust vectoring

    Science.gov (United States)

    Bare, E. Ann; Reubush, David E.

    1987-01-01

    A parametric investigation of the static internal performance of multifunction two-dimensional convergent-divergent nozzles has been made in the static test facility of the Langley 16-Foot Transonic Tunnel. All nozzles had a constant throat area and aspect ratio. The effects of upper and lower flap angles, divergent flap length, throat approach angle, sidewall containment, and throat geometry were determined. All nozzles were tested at a thrust vector angle that varied from 5.60 tp 23.00 deg. The nozzle pressure ratio was varied up to 10 for all configurations.

  13. Computational Study of an Axisymmetric Dual Throat Fluidic Thrust Vectoring Nozzle for a Supersonic Aircraft Application

    Science.gov (United States)

    Deere, Karen A.; Flamm, Jeffrey D.; Berrier, Bobby L.; Johnson, Stuart K.

    2007-01-01

    A computational investigation of an axisymmetric Dual Throat Nozzle concept has been conducted. This fluidic thrust-vectoring nozzle was designed with a recessed cavity to enhance the throat shifting technique for improved thrust vectoring. The structured-grid, unsteady Reynolds- Averaged Navier-Stokes flow solver PAB3D was used to guide the nozzle design and analyze performance. Nozzle design variables included extent of circumferential injection, cavity divergence angle, cavity length, and cavity convergence angle. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 1.89 to 10, with the fluidic injection flow rate equal to zero and up to 4 percent of the primary flow rate. The effect of a variable expansion ratio on nozzle performance over a range of freestream Mach numbers up to 2 was investigated. Results indicated that a 60 circumferential injection was a good compromise between large thrust vector angles and efficient internal nozzle performance. A cavity divergence angle greater than 10 was detrimental to thrust vector angle. Shortening the cavity length improved internal nozzle performance with a small penalty to thrust vector angle. Contrary to expectations, a variable expansion ratio did not improve thrust efficiency at the flight conditions investigated.

  14. Static performance of nonaxisymmetric nozzles with yaw thrust-vectoring vanes

    Science.gov (United States)

    Mason, Mary L.; Berrier, Bobby L.

    1988-01-01

    A static test was conducted in the static test facility of the Langley 16 ft Transonic Tunnel to evaluate the effects of post exit vane vectoring on nonaxisymmetric nozzles. Three baseline nozzles were tested: an unvectored two dimensional convergent nozzle, an unvectored two dimensional convergent-divergent nozzle, and a pitch vectored two dimensional convergent-divergent nozzle. Each nozzle geometry was tested with 3 exit aspect ratios (exit width divided by exit height) of 1.5, 2.5 and 4.0. Two post exit yaw vanes were externally mounted on the nozzle sidewalls at the nozzle exit to generate yaw thrust vectoring. Vane deflection angle (0, -20 and -30 deg), vane planform and vane curvature were varied during the test. Results indicate that the post exit vane concept produced resultant yaw vector angles which were always smaller than the geometric yaw vector angle. Losses in resultant thrust ratio increased with the magnitude of resultant yaw vector angle. The widest post exit vane produced the largest degree of flow turning, but vane curvature had little effect on thrust vectoring. Pitch vectoring was independent of yaw vectoring, indicating that multiaxis thrust vectoring is feasible for the nozzle concepts tested.

  15. Static performance of an axisymmetric nozzle with post-exit vanes for multiaxis thrust vectoring

    Science.gov (United States)

    Berrier, Bobby L.; Mason, Mary L.

    1988-01-01

    An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to determine the flow-turning capability and the nozzle internal performance of an axisymmetric convergent-divergent nozzle with post-exit vanes installed for multiaxis thrust vectoring. The effects of vane curvature, vane location relative to the nozzle exit, number of vanes, and vane deflection angle were determined. A comparison of the post-exit-vane thrust-vectoring concept with other thrust-vectoring concepts is provided. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 1.6 to 6.0.

  16. Comparison of CFD Simulations with Experimental Measurements of Nozzle Clogging in Continuous Casting of Steels

    Science.gov (United States)

    Mohammadi-Ghaleni, Mahdi; Asle Zaeem, Mohsen; Smith, Jeffrey D.; O'Malley, Ronald

    2016-08-01

    Measurements of clog deposit thickness on the interior surfaces of a commercial continuous casting nozzle are compared with computational fluid dynamics (CFD) predictions of melt flow patterns and particle-wall interactions to identify the mechanisms of nozzle clogging. A submerged entry nozzle received from industry was encased in epoxy and carefully sectioned to allow measurement of the deposit thickness on the internal surfaces of the nozzle. CFD simulations of melt flow patterns and particle behavior inside the nozzle were performed by combining the Eulerian-Lagrangian approach and detached eddy simulation turbulent model, matching the geometry and operating conditions of the industrial test. The CFD results indicated that convergent areas of the interior cross section of the nozzle increased the velocity and turbulence of the flowing steel inside the nozzle and decreased the clog deposit thickness locally in these areas. CFD simulations also predicted a higher rate of attachment of particles in the divergent area between two convergent sections of the nozzle, which matched the observations made in the industrial nozzle measurements.

  17. Evaluation of Nozzle Arrangement Focused on RPV Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Wook; Lee, Gyu Mahn; Jeoung, Kyeong Hoon; Kim, Tae Wan; Park, Keun Bae; Kim, Keung Koo

    2008-10-15

    The purpose of this study is to investigate the fabrication capacity of the reactor pressure vessel. For that reason, this study focuses on survey of the domestic equipment capacity and the feasible size for reactor pressure vessel. Also, the forecasting issues of adoption of new material for reactor pressure vessel are reviewed through typically examples. Additionally, an evaluation procedure for the design of nozzle is developed to meet ASME code requirements. The developed design procedure could provide typical references for the development of advanced reactor design in the future.

  18. Magnetic Nozzles for Plasma Thrusters: Acceleration, Thrust, and Detachment Mechanisms

    Science.gov (United States)

    2011-10-01

    was supported by Gobierno de España, ESP-2007-62694. Publisher Identifier S XXXX-XXXXXXX-X Simulation of plasma flows in divergent magnetic nozzles...Manuscript received ----- M. Merino and E. Ahedo are with the Universidad Politécnica de Madrid, Spain. Work was supported by Gobierno de España, ESP...tion thereon. Additional support came from the Gobierno de España (Project AYA-2010-16699). The authors thank Pro- fessor Martı́nez-Sánchez for his

  19. Fluidically Augmented Nozzles for Pulse Detonation Engine Applications

    Science.gov (United States)

    2011-12-01

    Nozzles 15. NUMBER OF PAGES 147 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE...COOH tpis91 *C2 g 6/01 C2H g 1/91 C2H2, acetylene g 5/01 C2H2,vinylidene g 4/02 CH2CO,ketene g 3/02... acetylene C2H2,vinylidene CH2CO,ketene O(CH)2O HO(CO)2OH C2H3,vinyl CH3CN CH3CO,acetyl C2H4 C2H4O,ethylen

  20. Two-phase nozzle flow and the subcharacteristic condition

    DEFF Research Database (Denmark)

    Linga, Gaute; Aursand, Peder; Flåtten, Tore

    2015-01-01

    We consider nozzle flow models for two-phase flow with phase transfer. Such models are based on energy considerations applied to the frozen and equilibrium limits of the underlying relaxation models. In this paper, we provide an explicit link between the mass flow rate predicted by these models a...... leakage of CO2 is presented, indicating that the frozen and equilibrium models provide significantly different predictions. This difference is comparable in magnitude to the modeling error introduced by applying simple ideal-gas/incompressible-liquid equations-of-state for CO2....

  1. Temperature-programmed desorption for membrane inlet mass spectrometry

    DEFF Research Database (Denmark)

    Ketola, R.A.; Grøn, C.; Lauritsen, F.R.

    1998-01-01

    We present a novel technique for analyzing volatile organic compounds in air samples using a solid adsorbent together with temperature-programmed desorption and subsequent detection by membrane inlet mass spectrometry (TPD-MIMS). The new system has the advantage of a fast separation of compounds...... prior to the detection by MIMS. The gaseous sample is simply adsorbed on the adsorbent, which is then rapidly heated from 30 degrees C to 250 degrees C at a rate of 50 degrees C/min, Trapped organic compounds are released from the adsorbent into a helium stream at different temperatures depending...

  2. An Investigation of Transonic Resonance in a Mach 2.2 Round Convergent-Divergent Nozzle

    Science.gov (United States)

    Dippold, Vance F., III; Zaman, Khairul B. M. Q.

    2015-01-01

    Hot-wire and acoustic measurements were taken for a round convergent nozzle and a round convergent-divergent (C-D) nozzle at a jet Mach number of 0.61. The C-D nozzle had a design Mach number of 2.2. Compared to the convergent nozzle jet flow, the Mach 2.2 nozzle jet flow produced excess broadband noise (EBBN). It also produced a transonic resonance tone at 1200 Herz. Computational simulations were performed for both nozzle flows. A steady Reynolds-Averaged Navier-Stokes simulation was performed for the convergent nozzle jet flow. For the Mach 2.2 nozzle flow, a steady RANS simulation, an unsteady RANS (URANS) simulation, and an unsteady Detached Eddy Simulation (DES) were performed. The RANS simulation of the convergent nozzle showed good agreement with the hot-wire velocity and turbulence measurements, though the decay of the potential core was over-predicted. The RANS simulation of the Mach 2.2 nozzle showed poor agreement with the experimental data, and more closely resembled an ideally-expanded jet. The URANS simulation also showed qualitative agreement with the hot-wire data, but predicted a transonic resonance at 1145 Herz. The DES showed good agreement with the hot-wire velocity and turbulence data. The DES also produced a transonic tone at 1135 Herz. The DES solution showed that the destabilization of the shock-induced separation region inside the nozzle produced increased levels of turbulence intensity. This is likely the source of the EBBN.

  3. Spray Characteristics of High-Pressure Mist Nozzle of Lubrication Device for Space Mechanisms%空间润滑装置高压雾化喷嘴的喷雾特性

    Institute of Scientific and Technical Information of China (English)

    盛明伟; 陈维山; 刘军考

    2011-01-01

    To solve the lubricating failure of spacecrafts in orbit for lack of lubrication, a high-pressure mist nozzle was applied to the spatial lubrication field. A gas-liquid two-phase flow model for direct mist nozzles was established, and the mist flow generating process was simulated using the software of computational fluid dynamic technology CFD-ACE +2009. On this basis, both the lubricant flow velocity and pressure distribution near the nozzle were investigated. By comparison of two high-viscosity fluids, NYE 2001 and Krytox 143AB, with diesel oil in numerical experiments, the effects of fluid physical parameters on pressure propagation and flow velocity variation were analyzed. The simulation results show that the high viscosity of aerospace lubricant NYE 2001 would inhibit the pressure transfer in the mist nozzle severely; for instance, the pressure decreased from 1.5 Mpa at the inlet to 0.42 Mpa at the end of the 1 mm long nozzle, with a declining rate of 97.2%. Therefore, overhigh viscosity of liquid and overlong nozzle are unfavorable to droplets spray.%为解决航天器在空间轨道运行时润滑失效的问题,将高压直射式雾化喷嘴应用到空间润滑领域,利用流体动力学软件CFD-ACE +2009,建立了直射式雾化喷嘴气液两相流模型,在此基础上,对润滑油喷雾流的生成过程进行数值模拟,并考察了喷嘴处液体流动速度及压力的分布情况.通过2种高粘度液体NYE 2001、Krytox 143AB与柴油的对比,分析了液体物理参数对液体内部压力传递及流速变化的影响.数值模拟结果表明:航空润滑油NYE 2001的高粘度严重阻碍入口压力的传递,当入口压力为15 MPa时,1 mm长的喷嘴末端压力下降到0.42 MPa,降幅达到97.2%;过高的液体粘度和过长的喷嘴,对液体喷雾流的形成产生不利影响.

  4. Configuration optimization of pulsed anti-riots water cannon gas nozzle based on CFD technology%基于CFD技术的脉冲防暴水炮高压气嘴的结构设计

    Institute of Scientific and Technical Information of China (English)

    战仁军; 汪送; 余代锐

    2011-01-01

    Water jet nozzle velocity is such a sensitive factor that may influence the technical performance of pulsed anti-riots water cannon. In order to study the influence of different gas-nozzle structure to water jet nozzle velocity,2-D fiow field with three different gas-nozzles with different inlet area is studied by adopting CFD technical value, in which large Eddy Simulation and VOF model were used to describe the turbulent flow distribution and track the gas-liquid interface both inside and outside of the pipe. The results show that bigger or smaller the gas-nozzle entrance acreage is,the launch process may become slower,while the gas-nozzle with different structure may not influence the gas-liquid distribution at first,but may cause different influence on first and second water jet atomization since gas-liquid mix process inside the pipe is changed.%射流出口速度值是影响脉冲防暴水炮技术性能的敏感因素,为研究不同结构气嘴对射流出口速度的影响,采用CFD技术数值研究了三种不同入口面积气嘴的二维流场,其中大涡模拟方法和二维非稳态的VOF模型被用于描述气嘴流场的湍流分布和追踪管内外的气液界面,研究发现过大或过小的气嘴入口面积都会减慢水炮的发射过程,不同的气嘴结构对于初始时刻的射流形状是没有影响的,但因改变了管内的气液参混过程,从而导致对射流的一次和二次雾化产生不同影响.

  5. Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 1: Test nozzles and acoustic data

    Science.gov (United States)

    Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

    1984-02-01

    Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Acoustic behavior as a function of nozzle flow passage geometry was measured. The acoustic data consist primarily of 1/3 octave band sound pressure levels and overall sound pressure levels. Detailed schematics and geometric characteristics of the six scale model nozzle configurations and acoustic test point definitions are presented. Tabulation of aerodynamic test conditions and a computer listing of the measured acoustic data are displayed.

  6. Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 1: Test nozzles and acoustic data

    Science.gov (United States)

    Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

    1984-01-01

    Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Acoustic behavior as a function of nozzle flow passage geometry was measured. The acoustic data consist primarily of 1/3 octave band sound pressure levels and overall sound pressure levels. Detailed schematics and geometric characteristics of the six scale model nozzle configurations and acoustic test point definitions are presented. Tabulation of aerodynamic test conditions and a computer listing of the measured acoustic data are displayed.

  7. Experimental observations of a complex, supersonic nozzle concept

    Science.gov (United States)

    Magstadt, Andrew; Berry, Matthew; Glauser, Mark; Ruscher, Christopher; Gogineni, Sivaram; Kiel, Barry; Skytop Turbulence Labs, Syracuse University Team; Spectral Energies, LLC. Team; Air Force Research Laboratory Team

    2015-11-01

    A complex nozzle concept, which fuses multiple canonical flows together, has been experimentally investigated via pressure, schlieren and PIV in the anechoic chamber at Syracuse University. Motivated by future engine designs of high-performance aircraft, the rectangular, supersonic jet under investigation has a single plane of symmetry, an additional shear layer (referred to as a wall jet) and an aft deck representative of airframe integration. Operating near a Reynolds number of 3 ×106 , the nozzle architecture creates an intricate flow field comprised of high turbulence levels, shocks, shear & boundary layers, and powerful corner vortices. Current data suggest that the wall jet, which is an order of magnitude less energetic than the core, has significant control authority over the acoustic power through some non-linear process. As sound is a direct product of turbulence, experimental and analytical efforts further explore this interesting phenomenon associated with the turbulent flow. The authors acknowledge the funding source, a SBIR Phase II project with Spectral Energies, LLC. and AFRL turbine engine branch under the direction of Dr. Barry Kiel.

  8. Plasma-based Control of Supersonic Nozzle Flow

    CERN Document Server

    Gaitonde, Datta V

    2009-01-01

    The flow structure obtained when Localized Arc Filament Plasma Actuators (LAFPA) are employed to control the flow issuing from a perfectly expanded Mach 1.3 nozzle is elucidated by visualizing coherent structures obtained from Implicit Large-Eddy Simulations. The computations reproduce recent experimental observations at the Ohio State University to influence the acoustic and mixing properties of the jet. Eight actuators were placed on a collar around the periphery of the nozzle exit and selectively excited to generate various modes, including first and second mixed (m = +/- 1 and m = +/- 2) and axisymmetric (m = 0). In this fluid dynamics video http://ecommons.library.cornell.edu/bitstream/1813/13723/2/Alljoinedtotalwithmodetextlong2-Datta%20MPEG-1.m1v, http://ecommons.library.cornell.edu/bitstream/1813/13723/3/Alljoinedtotalwithmodetextlong2-Datta%20MPEG-2.m2v}, unsteady and phase-averaged quantities are displayed to aid understanding of the vortex dynamics associated with the m = +/- 1 and m = 0 modes exci...

  9. Noise reduction in supersonic jets by nozzle fluidic inserts

    Science.gov (United States)

    Morris, Philip J.; McLaughlin, Dennis K.; Kuo, Ching-Wen

    2013-08-01

    Professor Philip Doak spent a very productive time as a consultant to the Lockheed-Georgia Company in the early 1970s. The focus of the overall research project was the prediction and reduction of noise from supersonic jets. Now, 40 years on, the present paper describes an innovative methodology and device for the reduction of supersonic jet noise. The goal is the development of a practical active noise reduction technique for low bypass ratio turbofan engines. This method introduces fluidic inserts installed in the divergent wall of a CD nozzle to replace hard-wall corrugation seals, which have been demonstrated to be effective by Seiner (2005) [1]. By altering the configuration and operating conditions of the fluidic inserts, active noise reduction for both mixing and shock noise has been obtained. Substantial noise reductions have been achieved for mixing noise in the maximum noise emission direction and in the forward arc for broadband shock-associated noise. To achieve these reductions (on the order of greater than 4 and 2 dB for the two main components respectively), practically achievable levels of injection mass flow rates have been used. The total injected mass flow rates are less than 4% of the core mass flow rate and the effective operating injection pressure ratio has been maintained at or below the same level as the nozzle pressure ratio of the core flow.

  10. Sludge mobilization with submerged nozzles in horizontal cylindrical tanks

    Energy Technology Data Exchange (ETDEWEB)

    Hylton, T.D.; Cummins, R.L.; Youngblood, E.L.; Perona, J.J.

    1995-10-01

    The Melton Valley Storage Tanks (MVSTs) and the evaporator service tanks at the Oak Ridge National Laboratory (ORNL) are used for the collection and storage of liquid low-level waste (LLLW). Wastes collected in these tanks are typically acidic when generated and are neutralized with sodium hydroxide to protect the tanks from corrosion; however, the high pH of the solution causes the formation of insoluble compounds that precipitate. These precipitates formed a sludge layer approximately 0.6 to 1.2 m (2 to 4 ft) deep in the bottom of the tanks. The sludge in the MVSTs and the evaporator service tanks will eventually need to be removed from the tanks and treated for final disposal or transferred to another storage facility. The primary options for removing the sludge include single-point sluicing, use of a floating pump, robotic sluicing, and submerged-nozzle sluicing. The objectives of this study were to (1) evaluate the feasibility of submerged-nozzle sluicing in horizontal cylindrical tanks and (2) obtain experimental data to validate the TEMPEST (time-dependent, energy, momentun, pressure, equation solution in three dimensions) computer code.

  11. Flow and acoustic features of a supersonic tapered nozzle

    Science.gov (United States)

    Gutmark, E.; Bowman, H. L.; Schadow, K. C.

    1992-05-01

    The acoustic and flow characteristics of a supersonic tapered jet were measured for free and shrouded flow configurations. Measurements were performed for a full range of pressure ratios including over- and underexpanded and design conditions. The supersonic tapered jet is issued from a converging-diverging nozzle with a 3∶1 rectangular slotted throat and a conical diverging section leading to a circular exit. The jet was compared to circular and rectangular supersonic jets operating at identical conditions. The distinct feature of the jet is the absence of screech tones in the entire range of operation. Its near-field pressure fluctuations have a wide band spectrum in the entire range of measurements, for Mach numbers of 1 to 2.5, for over- and underexpanded conditions. The free jet's spreading rate is nearly constant and similar to the rectangular jet, and in a shroud, the pressure drop it is inducing is linearly proportional to the primary jet Mach number. This behavior persisted in high adverse pressure gradients at overexpanded conditions, and with nozzle divergence angles of up to 35°, no inside flow separation was observed.

  12. An Investigation of Flow in Nozzle Hole of Dimethyl Ether

    Science.gov (United States)

    Kato, M.; Yokota, T.; Weber, J.; Gill, D.

    2015-12-01

    For over twenty years, DME has shown itself to be a most promising fuel for diesel combustion. DME is produced by simple synthesis of such common sources as coal, natural gas, biomass, and waste feedstock. DME is a flammable, thermally-stable liquid similar to liquefied petroleum gas (LPG) and can be handled like LPG. However, the physical properties of DME such as its low viscosity, lubricity and bulk modulus have negative effects for the fuel injection system, which have both limited the achievable injection pressures to about 500 bar and DME's introduction into the market. To overcome some of these effects, a common rail fuel injection system was adapted to operate with DME and produce injection pressures of up to 1000 bar. To understand the effect of the high injection pressure, tests were carried out using 2D optically accessed nozzles. This allowed the impact of the high vapour pressure of DME on the onset of cavitation in the nozzle hole to be assessed and improve the flow characteristics.

  13. Flow distribution in the inlet plenum of steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Khadamakar, H.P. [Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Patwardhan, A.W., E-mail: aw.patwardhan@ictmumbai.edu.in [Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Padmakumar, G.; Vaidyanathan, G. [Experimental Thermal Hydraulics Section, Separation Technology and Hydraulics Division, Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2011-10-15

    Highlights: > Various flow distribution devices have been studied to make the flow distribution uniform in axial as well as tangential direction. > Experiments were performed using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV). > CFD modeling has been carried out to give more insights. > Various flow distribution devices have been compared. - Abstract: The flow distribution in a 1/5th and 1/8th scale models of inlet plenum of steam generator (SG) has been studied by a combination of experiments and Computational Fluid Dynamics (CFD) simulations. The distribution of liquid sodium in the inlet plenum of the SG strongly affects the thermal as well as mechanical performance of the steam generator. Various flow distribution devices have been used to make the flow distribution uniform in axial as well as tangential direction in the window region. Experiments have been conducted to measure the radial velocity distribution using Ultrasonic Velocity Profiler (UVP) and Particle Image Velocimetry (PIV) under a variety of conditions. CFD modeling has been carried out for various configurations to give more insight into the flow distribution phenomena. The various flow distribution devices have been compared on the basis of a non-uniformity index parameter.

  14. Liquefied Bleed for Stability and Efficiency of High Speed Inlets

    Science.gov (United States)

    Saunders, J. David; Davis, David; Barsi, Stephen J.; Deans, Matthew C.; Weir, Lois J.; Sanders, Bobby W.

    2014-01-01

    A mission analysis code was developed to perform a trade study on the effectiveness of liquefying bleed for the inlet of the first stage of a TSTO vehicle. By liquefying bleed, the vehicle weight (TOGW) could be reduced by 7 to 23%. Numerous simplifying assumptions were made and lessons were learned. Increased accuracy in future analyses can be achieved by: Including a higher fidelity model to capture the effect of rescaling (variable vehicle TOGW). Refining specific thrust and impulse models ( T m a and Isp) to preserve fuel-to-air ratio. Implementing LH2 for T m a and Isp. Correlating baseline design to other mission analyses and correcting vehicle design elements. Implementing angle-of-attack effects on inlet characteristics. Refining aerodynamic performance (to improve L/D ratio at higher Mach numbers). Examining the benefit with partial cooling or densification of the bleed air stream. Incorporating higher fidelity weight estimates for the liquefied bleed system (heat exchange and liquid storage versus bleed duct weights) could be added when more fully developed. Adding trim drag or 6-degree-of-freedom trajectory analysis for higher fidelity. Investigating vehicle optimization for each of the bleed configurations.

  15. Technology Review of Modern Gas Turbine Inlet Filtration Systems

    Directory of Open Access Journals (Sweden)

    Melissa Wilcox

    2012-01-01

    Full Text Available An inlet air filtration system is essential for the successful operation of a gas turbine. The filtration system protects the gas turbine from harmful debris in the ambient air, which can lead to issues such as FOD, erosion, fouling, and corrosion. These issues if not addressed will result in a shorter operational life and reduced performance of the gas turbine. Modern day filtration systems are comprised of multiple filtration stages. Each stage is selected based on the local operating environment and the performance goals for the gas turbine. Selection of these systems can be a challenging task. This paper provides a review of the considerations for selecting an inlet filtration system by covering (1 the characteristics of filters and filter systems, (2 a review of the many types of filters, (3 a detailed look at the different environments where the gas turbine can operate, (4 a process for evaluating the site where the gas turbine will be or is installed, and (5 a method to compare various filter system options with life cycle cost analysis.

  16. An Evaluation on the Effect of Residual Stress and Phase Transformation Improvement by Welding in Half Nozzle Repair Method of BMI Nozzle

    Energy Technology Data Exchange (ETDEWEB)

    Park, Giyeol; Lee, Sangho; Kim, Taeryong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2015-10-15

    In this study, it is evaluated that the effect of Pad welding for the Half Nozzle Repair method in the BMI the main instrument of NPP using SYSWELD which is the weld analysis code. BMI (Bottom Mounted Instrumentation) Nozzle is less sensitive to PWSCC generation of Alloy 600 material because the operation temperature is in the relatively low temperature region. But, it is very important to ensure the maintenance of the technical preparation for the damage because Nozzle is installed at reactor bottom head which is not possible to replace. A damage of Reactor Vessel BMI Nozzle under operation was confirmed as No.1 and No.46 Nozzle was observed to find acid precipitate while inspecting the reactor vessel bottom head of STP unit 1 in April 2003. Thus maintenance technology was developed such as Half Nozzle Repair in order to prevent damage of J-Groove welding including BMI Nozzle. In case of J-Groove welding, after cutting J-Groove satisfied the condition required by welding geometry design, new Nozzle of Alloy 690 material is inserted. And then welding applied for welding process parameters is performed when welding procedure applied for Alloy 52 weld filler metal is satisfied. The result of evaluation can be obtained as the following. 1) In order to prevent PWSCC of the BMI nozzle, the Half Nozzle Repair method was performed. As the result, the material Alloy 690 which has the strong corrosion resistance, one of the main factors of PWSCC, was replaced to prevent PWSCC. However, the higher tensile stress, another factor of PWSCC, than yield strength (350MPa) was occurred for Alloy 690 in the inner diameter of the nozzle contacting with the primary water in terms of the Hoop Stress. But compared to the yield strength, it cannot be seen much difference, so the prevention of PWSCC can be estimated. However, additional mechanical surface enhancing procedure such as pinning after welding is required so as to reduce the high tensile stress of the entire welding portion. 2

  17. A refractory steerable nozzle for air and fuel injection in thermal plant boiler combustors

    Energy Technology Data Exchange (ETDEWEB)

    Peschard, J.

    1993-10-01

    The horizontal walls of the tiltable (downwards or upwards) nozzles are corrugated in such a way that they may undergo thermal expansion without cracking. The vertical walls are double-face designed with air flowing inside for cooling. The nozzle is made of refractory steel. Application to air injection with or without pulverized coal or gas, in thermal plants.

  18. Measurement and classification methods using the ASAE S572-1 reference nozzles

    Science.gov (United States)

    An increasing number of spray nozzle and agrochemical manufacturers are incorporating droplet size measurements into both research and development with each laboratory invariably having their own sampling setup and procedures, particularly with regard to both measurement distance from the nozzle and...

  19. Prediction of rarefied micro-nozzle flows using the SPARTA library

    Science.gov (United States)

    Deschenes, Timothy R.; Grot, Jonathan

    2016-11-01

    The accurate numerical prediction of gas flows within micro-nozzles can help evaluate the performance and enable the design of optimal configurations for micro-propulsion systems. Viscous effects within the large boundary layers can have a strong impact on the nozzle performance. Furthermore, the variation in collision length scales from continuum to rarefied preclude the use of continuum-based computational fluid dynamics. In this paper, we describe the application of a massively parallel direct simulation Monte Carlo (DSMC) library to predict the steady-state and transient flow through a micro-nozzle. The nozzle's geometric configuration is described in a highly flexible manner to allow for the modification of the geometry in a systematic fashion. The transient simulation highlights a strong shock structure that forms within the converging portion of the nozzle when the expanded gas interacts with the nozzle walls. This structure has a strong impact on the buildup of the gas in the nozzle and affects the boundary layer thickness beyond the throat in the diverging section of the nozzle. Future work will look to examine the transient thrust and integrate this simulation capability into a web-based rarefied gas dynamics prediction software, which is currently under development.

  20. Borehole Miner - Extendible Nozzle Development for Radioactive Waste Dislodging and Retrieval from Underground Storage Tanks

    Energy Technology Data Exchange (ETDEWEB)

    CW Enderlin; DG Alberts; JA Bamberger; M White

    1998-09-25

    This report summarizes development of borehole-miner extendible-nozzle water-jetting technology for dislodging and retrieving salt cake, sludge} and supernate to remediate underground storage tanks full of radioactive waste. The extendible-nozzle development was based on commercial borehole-miner technology.

  1. A Computational Study of a New Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    Science.gov (United States)

    Deere, Karen A.; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2005-01-01

    A computational investigation of a two-dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. Several design cycles with the structured-grid, computational fluid dynamics code PAB3D and with experiments in the NASA Langley Research Center Jet Exit Test Facility have been completed to guide the nozzle design and analyze performance. This paper presents computational results on potential design improvements for best experimental configuration tested to date. Nozzle design variables included cavity divergence angle, cavity convergence angle and upstream throat height. Pulsed fluidic injection was also investigated for its ability to decrease mass flow requirements. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 2 to 7, with the fluidic injection flow rate equal to 3 percent of the primary flow rate. Computational results indicate that increasing cavity divergence angle beyond 10 is detrimental to thrust vectoring efficiency, while increasing cavity convergence angle from 20 to 30 improves thrust vectoring efficiency at nozzle pressure ratios greater than 2, albeit at the expense of discharge coefficient. Pulsed injection was no more efficient than steady injection for the Dual Throat Nozzle concept.

  2. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    Science.gov (United States)

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  3. Effects of nozzle-strut integrated design concepton on the subsonic turbine stage flowfield

    Science.gov (United States)

    Liu, Jun; Du, Qiang; Liu, Guang; Wang, Pei; Zhu, Junqiang

    2014-10-01

    In order to shorten aero-engine axial length, substituting the traditional long chord thick strut design accompanied with the traditional low pressure(LP) stage nozzle, LP turbine is integrated with intermediate turbine duct (ITD). In the current paper, five vanes of the first stage LP turbine nozzle is replaced with loaded struts for supporting the engine shaft, and providing oil pipes circumferentially which fulfilled the areo-engine structure requirement. However, their bulky geometric size represents a more effective obstacle to flow from high pressure (HP) turbine rotor. These five struts give obvious influence for not only the LP turbine nozzle but also the flowfield within the ITD, and hence cause higher loss. Numerical investigation has been undertaken to observe the influence of the Nozzle-Strut integrated design concept on the flowfield within the ITD and the nearby nozzle blades. According to the computational results, three main conclusions are finally obtained. Firstly, a noticeable low speed area is formed near the strut's leading edge, which is no doubt caused by the potential flow effects. Secondly, more severe radial migration of boundary layer flow adjacent to the strut's pressure side have been found near the nozzle's trailing edge. Such boundary layer migration is obvious, especially close to the shroud domain. Meanwhile, radial pressure gradient aggravates this phenomenon. Thirdly, velocity distribution along the strut's pressure side on nozzle's suction surface differs, which means loading variation of the nozzle. And it will no doubt cause nonuniform flowfield faced by the downstream rotor blade.

  4. Hybrid two fuel system nozzle with a bypass connecting the two fuel systems

    Science.gov (United States)

    Varatharajan, Balachandar [Cincinnati, OH; Ziminsky, Willy Steve [Simpsonville, SC; Yilmaz, Ertan [Albany, NY; Lacy, Benjamin [Greer, SC; Zuo, Baifang [Simpsonville, SC; York, William David [Greer, SC

    2012-05-29

    A hybrid fuel combustion nozzle for use with natural gas, syngas, or other types of fuels. The hybrid fuel combustion nozzle may include a natural gas system with a number of swozzle vanes and a syngas system with a number of co-annular fuel tubes.

  5. Slag Prediction in Submerged Rocket Nozzle Through Two-Phase CFD Simulations

    Directory of Open Access Journals (Sweden)

    Amit Kumar Chaturvedi

    2015-04-01

    Full Text Available A computational procedure has been established to predict the slag in a practical solid rocket motor with submerged nozzle. Both single-phase and two-phase flow analyses have been performed in the rocket motor port. Three-dimensional Navier-Stokes equations along with SST turbulence model have been solved for gas-phase calculations. The effect of ejected alumina particles from the propellant geometry on the flow field has been simulated through Lagrangian tracking method. The computational methodology is firstly validated by comparing against other numerical results of rocket motors available in the literature before applying the same to predict the slag accumulation of a submerged rocket motor for strategic applications. Burn-back geometries at different instants have been simulated and parametric studies were performed to find out the effect of Al2O3 particle size. It was observed that the slag capture rate increases uniformly with A12O3 particle size. The predicted slag accumulation data match closely with the ground test data for the range of conditions simulated in the present work.Defence Science Journal, Vol. 65, No. 2, March 2015, pp.99-106, DOI:http://dx.doi.org/10.14429/dsj.65.7147 Normal 0 false false false EN-US X-NONE X-NONE

  6. Oregon inlet: Hydrodynamics, volumetric flux and implications for larval fish transport

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, C.R. [National Oceanic and Atmospheric Administration, Silver Springs, MD (United States); Pietrafesa, L.J. [North Carolina State Univ., Raleigh, NC (United States). Department of Marine, Earth and Atmospheric Sciences

    1997-05-01

    The temporal response of Oregon Inlet currents to atmospheric forcing and sea level fluctuations is analyzed using time and frequency domain analysis. Temporally persistent and spatially extensive ebb and flood events are identified using data sets from both within and outside of Oregon Inlet. Prism estimates are made to generate a time series of volumetric flux of water transported through the inlet. Water masses flooding into the Pamlico Sound via Oregon Inlet are identified in temperature (T) and salinity (S) space to determine their source of origin. Correlations are examined between the atmospheric wind field, the main axial slope of the inlet`s water level, inlet flow and T, S properties. Synoptic scale atmospheric wind events are found to dramatically and directly affect the transport of water towards (away from) the inlet on the ocean side, in concert with the contemporaneous transport away from (towards) the inlet on the estuary side, and a subsequent flooding into (out of) the estuary via Oregon Inlet. Thus, while astronomical tidal flooding and ebbing events are shown to be one-sided as coastal waters either set-up or set-down, synoptic scale wind events are shown to be manifested as a two-sided in-phase response set-up and set-down inside and outside the inlet, and thus are extremely effective in driving currents through the inlet. These subinertial frequency flood events are believed to be essential for both the recruitment and subsequent retention of estuarine dependent larval fish from the coastal ocean into Pamlico Sound. Year class strength of these finish may be determined annually by the relative strength and timing of these climatological wind events.

  7. Is there an association between Helicobacter pylori in the inlet patch and globus sensation?

    Institute of Scientific and Technical Information of China (English)

    Hakan; Alagozlu; Zahide; Simsek; Selahattin; Unal; Mehmet; Cindoruk; Sukru; Dumlu; Ayse; Dursun

    2010-01-01

    AIM:To determine the association between Helicobacter pylori(H.pylori)and globus sensation(GS)in the patients with cervical inlet patch. METHODS:Sixty-eight patients with esophageal inlet patches were identified from 6760 consecutive patients undergoing upper gastrointestinal endoscopy prospectively.In these 68 patients with cervical inlet patches, symptoms of globus sensation(lump in the throat), hoarseness,sore throat,frequent clearing of the throat,cough,dysphagia,odynophagia of at least 3 mo duration wa...

  8. Oregon inlet: Hydrodynamics, volumetric flux and implications for larval fish transport

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, C.R. [National Oceanic and Atmospheric Administration, Silver Springs, MD (United States); Pietrafesa, L.J. [North Carolina State Univ., Raleigh, NC (United States). Department of Marine, Earth and Atmospheric Sciences

    1997-05-01

    The temporal response of Oregon Inlet currents to atmospheric forcing and sea level fluctuations is analyzed using time and frequency domain analysis. Temporally persistent and spatially extensive ebb and flood events are identified using data sets from both within and outside of Oregon Inlet. Prism estimates are made to generate a time series of volumetric flux of water transported through the inlet. Water masses flooding into the Pamlico Sound via Oregon Inlet are identified in temperature (T) and salinity (S) space to determine their source of origin. Correlations are examined between the atmospheric wind field, the main axial slope of the inlet`s water level, inlet flow and T, S properties. Synoptic scale atmospheric wind events are found to dramatically and directly affect the transport of water towards (away from) the inlet on the ocean side, in concert with the contemporaneous transport away from (towards) the inlet on the estuary side, and a subsequent flooding into (out of) the estuary via Oregon Inlet. Thus, while astronomical tidal flooding and ebbing events are shown to be one-sided as coastal waters either set-up or set-down, synoptic scale wind events are shown to be manifested as a two-sided in-phase response set-up and set-down inside and outside the inlet, and thus are extremely effective in driving currents through the inlet. These subinertial frequency flood events are believed to be essential for both the recruitment and subsequent retention of estuarine dependent larval fish from the coastal ocean into Pamlico Sound. Year class strength of these finish may be determined annually by the relative strength and timing of these climatological wind events.

  9. Direct Numerical Simulation of Acoustic Noise Generation from the Nozzle Wall of a Hypersonic Wind Tunnel

    Science.gov (United States)

    Huang, Junji; Duan, Lian; Choudhari, Meelan M.

    2017-01-01

    The acoustic radiation from the turbulent boundary layer on the nozzle wall of a Mach 6 Ludwieg Tube is simulated using Direct Numerical Simulations (DNS), with the flow conditions falling within the operational range of the Mach 6 Hypersonic Ludwieg Tube, Braunschweig (HLB). The mean and turbulence statistics of the nozzle-wall boundary layer show good agreement with those predicted by Pate's correlation and Reynolds Averaged Navier-Stokes (RANS) computations. The rms pressure fluctuation P'(rms)/T(w) plateaus in the freestream core of the nozzle. The intensity of the freestream noise within the nozzle is approximately 20% higher than that radiated from a single at pate with a similar freestream Mach number, potentially because of the contributions to the acoustic radiation from multiple azimuthal segments of the nozzle wall.

  10. Controllable deposition distance of aligned pattern via dual-nozzle near-field electrospinning

    Science.gov (United States)

    Wang, Zhifeng; Chen, Xindu; Zeng, Jun; Liang, Feng; Wu, Peixuan; Wang, Han

    2017-03-01

    For large area micro/nano pattern printing, multi-nozzle electrohydrodynamic (EHD) printing setup is an efficient method to boost productivity in near-field electrospinning (NFES) process. And controlling EHD multi-jet accurate deposition under the interaction of nozzles and other parameters are crucial concerns during the process. The influence and sensitivity of various parameters such as the needle length, needle spacing, electrode-to-collector distance, voltage etc. on the direct-write patterning performance was investigated by orthogonal experiments with dual-nozzle NFES setup, and then the deposition distance estimated based on a novel model was compared with measurement results and proven. More controllable deposition distance and much denser of aligned naofiber can be achieved by rotating the dual-nozzle setup. This study can be greatly contributed to estimate the deposition distance and helpful to guide the multi-nozzle NFES process to accurate direct-write pattern in manufacturing process in future.

  11. Gas Nozzle Effect on the Deposition of Polysilicon by Monosilane Siemens Reactor

    Directory of Open Access Journals (Sweden)

    Seung Oh Kang

    2012-01-01

    Full Text Available Deposition of polysilicon (poly-Si was tried to increase productivity of poly-Si by using two different types of gas nozzle in a monosilane Bell-jar Siemens (MS-Siemens reactor. In a mass production of poly-Si, deposition rate and energy consumption are very important factors because they are main performance indicators of Siemens reactor and they are directly related with the production cost of poly-Si. Type A and B nozzles were used for investigating gas nozzle effect on the deposition of poly-Si in a MS-Siemens reactor. Nozzle design was analyzed by computation cluid dynamics (CFD. Deposition rate and energy consumption of poly-Si were increased when the type B nozzle was used. The highest deposition rate was 1 mm/h, and the lowest energy consumption was 72 kWh⋅kg-1 in this study.

  12. Thrust distribution for attitude control in a variable thrust propulsion system with four ACS nozzles

    Science.gov (United States)

    Lim, Yeerang; Lee, Wonsuk; Bang, Hyochoong; Lee, Hosung

    2017-04-01

    A thrust distribution approach is proposed in this paper for a variable thrust solid propulsion system with an attitude control system (ACS) that uses a reduced number of nozzles for a three-axis attitude maneuver. Although a conventional variable thrust solid propulsion system needs six ACS nozzles, this paper proposes a thrust system with four ACS nozzles to reduce the complexity and mass of the system. The performance of the new system was analyzed with numerical simulations, and the results show that the performance of the system with four ACS nozzles was similar to the original system while the mass of the whole system was simultaneously reduced. Moreover, a feasibility analysis was performed to determine whether a thrust system with three ACS nozzles is possible.

  13. Experimental Study on Shock Wave Structures in Constant-area Passage of Cold Spray Nozzle

    Institute of Scientific and Technical Information of China (English)

    Hiroshi KATANODA; Takeshi MATSUOKA; Kazuyasu MATSUO

    2007-01-01

    Cold spray is a technique to make a coating on a wide variety of mechanical or electric parts by spraying solid particles accelerated through a high-speed gas flow in a converging-diverging nozzle. In this study, pseudo-shock waves in a modeled cold spray nozzle as well as high-speed gas jets are visualized by schlieren technique. The schlieren photographs reveals the supersonic flow with shock train in the nozzle. Static pressure along the barrel wall is also measured. The location of the head of pseudo-shock wave and its pressure distribution along the nozzle wall are analytically explained by using a formula of pseudo-shock wave. The analytical results show that the supersonic flow accompanying shock wave in the nozzle should be treated as pseudo-shock wave instead of normal shock wave.

  14. Numerical simulation of carbon dioxide removal from natural gas using supersonic nozzles

    Science.gov (United States)

    Sun, Wenjuan; Cao, Xuewen; Yang, Wen; Jin, Xuetang

    2017-03-01

    Supersonic separation is a technology potentially applicable to natural gas decarbonation process. Preliminary research on the performance of supersonic nozzle in the removal of carbon dioxide from natural gas is presented in this study. Computational Fluid Dynamics (CFD) technique is used to simulate the flow behavior inside the supersonic nozzle. The CFD model is validated successfully by comparing its results to the data borrowed from the literature. The results indicate that the liquefaction of carbon dioxide can be achieved in the properly designed nozzle. Shock wave occurs in the divergent section of the nozzle with the increase of the back pressure, destroying the liquefaction process. In the supersonic separator, the shock wave should be kept outside of the nozzle.

  15. Technical Analysis of Kort Nozzle Application for SPOB Ship 4990 DWT on River

    Directory of Open Access Journals (Sweden)

    Tony Bambang Musriyadi

    2017-06-01

    Full Text Available Propeller is a locomotor shaped vanes are used to drive ships, and also propellers which serves to move tehaga by changing the turning force of the propeller thrust menggerakakan into the vessel. In increasing the value of the thrust to be generated that is by applying the kort nozzle propeller. The method used in this study using CFD (Computional Fluid Dynamic, and the variation is from the conventional propeller models, with a kort nozzle propeller type kort nozzle type 19A and 37. Based on the findings that the kort nozzle propeller with the addition of the value of the thrust , propeller efficiency and torque generated. The driving force value is by using kort nozzle propeller type 37 amounted to 349.27 kN.

  16. Modification of Bonding Strength Test of WC HVOF Thermal Spray Coating on Rocket Nozzle

    Directory of Open Access Journals (Sweden)

    Bondan Sofyan

    2010-10-01

    Full Text Available One way to reduce structural weight of RX-100 rocket is by modifying the nozzle material and processing. Nozzle is the main target in weight reduction due to the fact that it contributes 30 % to the total weight of the structur. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel thermal spray layer. This paper presents the characterization of nozzle base material as well as the modification of bonding strength test, by designing additional jig to facilitate testing processes while maintaining level of test accuracy. The results showed that the material used for  RX-100 rocket nozzle is confirmed to be S45C steel. Modification of the bonding strength test was conducted by utilizing chains, which improve test flexibility and maintains level of accuracy of the test.

  17. Ultrasonic Phased Array Evaluation of Control Rod Drive Mechanism (CRDM) Nozzle Interference Fit and Weld Region

    Energy Technology Data Exchange (ETDEWEB)

    Cinson, Anthony D.; Crawford, Susan L.; MacFarlan, Paul J.; Mathews, Royce; Hanson, Brady D.; Diaz, Aaron A.

    2011-10-01

    In this investigation, non-destructive and destructive testing were used to evaluate potential boric acid leakage paths around an Alloy 600 CRDM penetration (Nozzle 63) from the North Anna Unit 2 reactor pressure vessel head that was removed from service in 2003. For this investigation, Nozzle 63 was examined using phased array ultrasonic testing. Prior to examining Nozzle 63, a CRDM penetration mockup with known notches and boric acid deposits was used to assess probe sensitivity, resolution and calibration. Following the non-destructive testing of Nozzle 63, the nozzle was destructively examined to visually assess the leak paths. These destructive and nondestructive results are compared and results are presented. The results of this investigation may be used by NRC to evaluate licensees’ volumetric leak path assessment methodologies and to support regulatory inspection requirements.

  18. Computational Fluid Dynamics Modeling of a Supersonic Nozzle and Integration into a Variable Cycle Engine Model

    Science.gov (United States)

    Connolly, Joseph W.; Friedlander, David; Kopasakis, George

    2015-01-01

    This paper covers the development of an integrated nonlinear dynamic simulation for a variable cycle turbofan engine and nozzle that can be integrated with an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. A previously developed variable cycle turbofan engine model is used for this study and is enhanced here to include variable guide vanes allowing for operation across the supersonic flight regime. The primary focus of this study is to improve the fidelity of the model's thrust response by replacing the simple choked flow equation convergent-divergent nozzle model with a MacCormack method based quasi-1D model. The dynamic response of the nozzle model using the MacCormack method is verified by comparing it against a model of the nozzle using the conservation element/solution element method. A methodology is also presented for the integration of the MacCormack nozzle model with the variable cycle engine.

  19. Design and testing of low-divergence elliptical-jet nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Rouly, Etienne; Warkentin, Andrew; Bauer, Robert [Dalhousie University, Halifax (China)

    2015-05-15

    A novel approach was developed to design and fabricate nozzles to produce high-pressure low-divergence fluid jets. Rapid-prototype fabrication allowed for myriad experiments investigating effects of different geometric characteristics of nozzle internal geometry on jet divergence angle and fluid distribution. Nozzle apertures were elliptical in shape with aspect ratios between 1.00 and 2.45. The resulting nozzle designs were tested and the lowest elliptical jet divergence angle was 0.4 degrees. Nozzle pressures and flowrates ranged from 0.32 to 4.45 MPa and 13.6 to 37.9 LPM, respectively. CimCool CimTech 310 machining fluid was used in all experiments at a Brix concentration of 6.6 percent.

  20. Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes

    Science.gov (United States)

    Tan, L.; Zha, L.; Cao, S. L.; Wang, Y. C.; Gui, S. B.

    2015-01-01

    The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.

  1. Inlet boundary conditions for shock wave propagation problems in air ducts

    Science.gov (United States)

    Fashbaugh, R. H.

    1992-03-01

    Shock waves propagating into air ducting systems are numerically studied using data from Kriebel (1972). Small-scale junctions mounted in shock tubes with an incident shock wave are considered. The stagnation pressure ratio through a duct inlet is evaluated for various junction types. The logarithm of this ratio varies linearly with the Mach number of the flow behind the incident shock wave. The static pressure inside the inlet is established using experimental data with given Mach numbers of the incident and inlet flows. A constant stagnation enthalpy through the inlet junction is assumed to establish inflow to the duct.

  2. Design concept of three-dimensional section controllable internal waverider hypersonic inlet

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream mass. On the basis of the association between hypersonic waverider airframe and streamtraced hypersonic inlet, the waverider concept is extended to yield results for the internal flows, namely internal waverider concept. It is proven theoretically that not osculating cones but osculating axisymmetric theory is appropriate for the design of section controllable internal waverider inlet. And two design methods out of the internal waverider concept are proposed subsequently to construct two inlets with specific section shape request, triangle to ellipse and rectangle to ellipse ones. The calculation results show that the inlets are capable of keeping their shock structures and the main flow characteristics exactly as their derived flowfield. Further, the inlets successfully capture all the upstream mass despite their complicated cross-section transitions. It is believed that the concept proposed ex- plores a new way of designing three-dimensional hypersonic inlets with special demand of section shape transition. However, the detailed flow characteristic and the performance of the internal waverider inlets are still under investigation.

  3. Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model

    Science.gov (United States)

    Csank, Jeffrey T.; Stueber, Thomas J.

    2013-01-01

    A dual flow-path inlet for a turbine based combined cycle (TBCC) propulsion system is to be tested in order to evaluate methodologies for performing a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms which are designed to maintain shock position during inlet disturbances. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the development of a mode transition schedule for the HiTECC simulation that is analogous to the development of inlet performance maps. Inlet performance maps, derived through experimental means, describe the performance and operability of the inlet as the splitter closes, switching power production from the turbine engine to the Dual Mode Scram Jet. With knowledge of the operability and performance tradeoffs, a closed loop system can be designed to optimize the performance of the inlet. This paper demonstrates the design of the closed loop control system and benefit with the implementation of a Proportional-Integral controller, an H-Infinity based controller, and a disturbance observer based controller; all of which avoid inlet unstart during a mode transition with a simulated disturbance that would lead to inlet unstart without closed loop control.

  4. Design concept of three-dimensional section controllable internal waverider hypersonic inlet

    Institute of Scientific and Technical Information of China (English)

    YOU YanCheng; LIANG DeWang

    2009-01-01

    A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream mass. On the basis of the association between hypersonic waverider airframe and streamtraced hypersonic inlet, the waverider concept is extended to yield results for the internal flows,namely internal waverider concept. It is proven theoretically that not osculating cones but osculating axisymmetric theory is appropriate for the design of section controllable internal wsverider inlet. And two design methods out of the internal waverider concept are proposed subsequently to construct two inlets with specific section shape request, triangle to ellipse and rectangle to ellipse ones. The calculation results show that the inlets are capable of keeping their shock structures and the main flow characteristics exactly as their derived flowfield. Further, the inlets successfully capture all the upstream mass despite their complicated cross-section transitions. It is believed that the concept proposed explores a new way of designing three-dimensional hypersonic inlets with special demand of section shape transition. However, the detailed flow characteristic and the performance of the internal waverider inlets are still under investigation.

  5. High Pressure Atmospheric Sampling Inlet System for Venus or the Gas Giants Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized high pressure atmospheric sampling inlet system for sample acquisition in extreme planetary environments,...

  6. 'Grounded' Politics

    DEFF Research Database (Denmark)

    Schmidt, Garbi

    2012-01-01

    play within one particular neighbourhood: Nørrebro in the Danish capital, Copenhagen. The article introduces the concept of grounded politics to analyse how groups of Muslim immigrants in Nørrebro use the space, relationships and history of the neighbourhood for identity political statements....... The article further describes how national political debates over the Muslim presence in Denmark affect identity political manifestations within Nørrebro. By using Duncan Bell’s concept of mythscape (Bell, 2003), the article shows how some political actors idealize Nørrebro’s past to contest the present...

  7. Analyses of Cryogenic Propellant Tank Pressurization based upon Ground Experiments

    OpenAIRE

    Ludwig, Carina; Dreyer, Michael

    2012-01-01

    The pressurization system of cryogenic propellant rockets requires on-board pressurant gas. The objective of this study was to analyze the influence of the pressurant gas temperature on the required pressurant gas mass in terms of lowering the launcher mass. First, ground experiments were performed in order to investigate the pressurization process with regard to the influence of the pressurant gas inlet temperature. Second, a system study for the cryogenic upper stage of a sma...

  8. PIV Measurements of Chevrons on F400-Series Tactical Aircraft Nozzle Model

    Science.gov (United States)

    Bridges, James; Wernet, Mark P.; Frate, Franco C.

    2011-01-01

    Reducing noise of tactical jet aircraft has taken on fresh urgency as core engine technologies allow higher specific-thrust engines and as society become more concerned for the health of its military workforce. Noise reduction on this application has lagged the commercial field as incentives for quieting military aircraft have not been as strong as in their civilian counterparts. And noise reduction strategies employed on civilian engines may not be directly applicable due to the differences in exhaust system architecture and mission. For instance, the noise reduction technology of chevrons, examined in this study, will need to be modified to take into account the special features of tactical aircraft nozzles. In practice, these nozzles have divergent slats that are tied to throttle position, and at take off the jet flow is highly overexpanded as the nozzle is optimized for cruise altitude rather than sea level. In simple oil flow visualization experiments conducted at the onset of the current test program flow barely stays attached at end of nozzle at takeoff conditions. This adds a new twist to the design of chevrons. Upon reaching the nozzle exit the flow shrinks inward radially, meaning that for a chevron to penetrate the flow it must extend much farther away from the baseline nozzle streamline. Another wrinkle is that with a variable divergence angle on the nozzle, the effective penetration will differ with throttle position and altitude. The final note of realism introduced in these experiments was to simulate the manner in which bypass flow is bled into the nozzle wall in real engines to cool the nozzle, which might cause very fat boundary layer at exit. These factors, along with several other issues specific to the application of chevrons to convergent-divergent nozzles have been explored with particle image velocimetry measurements and are presented in this paper.

  9. Two-fluid spray atomisation and pneumatic nozzles for fluid bed coating/agglomeration purposes: A review

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, Poul; Jensen, Anker Degn

    2008-01-01

    understood. This paper provides a systematic and up-to-date review of two-fluid nozzle designs and principles together with a presentation of nozzle fundamentals introducing basic nozzle theory and thermodynamics. Correlations for the prediction of mean droplet diameters are reviewed, compared...

  10. Experiment and analysis of performance parameters for refraction nozzle in vent wash exhaust hood%运水烟罩内折射式喷头性能参数分析及试验

    Institute of Scientific and Technical Information of China (English)

    何红勤; 袁寿其; 袁建平; 张杰; 刘晓凡

    2009-01-01

    In order to reduce the effect of cooking fume pollution on environment,the influence on the cooking fume′s cleaning effect of avent wash exhaust hood by the atomizing characteristic of nozzle was discussed. The experiments of the globoidal sector and the angle including 115°,120°,135°,140°,150° of direct sector refraction nozzle were carried out. Several parameters, i.e., velocity of flow, range of the nozzle, spray area, size of grain, and water distribution for the six refraction nozzles were measured under five pressures. The atomization performance was analyzed. The relations between these parameters were determined. Through the experiments it was found that the inlet pressure is directly proportional to the velocity of flow, range of the nozzle and spray area. The inlet pressure is inversely proportional to the size of grain. The best working pressure of the vent wash exhaust hood is 0.30 MPa. The cooking fume′s clea-ning effect of direct sector is better than globoidal sector refraction nozzle. The angle of 120°was selected for straight refractive nozzle. Its uniformity coefficient, atomization and spray area are the best.%为了降低油烟对环境的污染,研究了运水烟罩内固定喷头的喷射雾化特性对运水烟罩油烟净化效果的影响.对弧面扇形折射式喷头和折射锥角分别为115°,120°,135°,140°和150°的直面扇形折射式喷头进行试验研究,测量了这6个不同型号的折射式喷头在5种不同工作压力下的流速、射程、喷洒面积、粒径大小以及水量分布等参数的变化情况,分析了雾化性能,探寻各参数之间的关系及变化规律.结果表明:流速、射程、喷洒面积均与工作压力成正比;雨滴粒径大小与工作压力成反比;喷头的最佳工作压力为0.30 MPa;直面折射式喷头比弧面折射式喷头油烟净化效果好;120°折射直面扇形喷头水量分布最均匀,雾化效果最好,喷洒面积最大.

  11. A novel design method for ground source heat pump

    Directory of Open Access Journals (Sweden)

    Dong Xing-Jie

    2014-01-01

    Full Text Available This paper proposes a novel design method for ground source heat pump. The ground source heat pump operation is controllable by using several parameters, such as the total meters of buried pipe, the space between wells, the thermal properties of soil, thermal resistance of the well, the initial temperature of soil, and annual dynamic load. By studying the effect of well number and well space, we conclude that with the increase of the well number, the inlet and outlet water temperatures decrease in summer and increase in winter, which enhance the efficiency of ground source heat pump. The well space slightly affects the water temperatures, but it affects the soil temperature to some extent. Also the ground source heat pump operations matching with cooling tower are investigated to achieve the thermal balance. This method greatly facilitates ground source heat pump design.

  12. Inlet throttling effect on the boiling two-phase flow stability in a natural circulation loop with a chimney

    Science.gov (United States)

    Furuya, M.; Inada, F.; Yasuo, A.

    Experiments have been conducted to investigate an effect of inlet restriction on the thermal-hydraulic stability. A Test facility used in this study was designed and constructed to have non-dimensional values that are nearly equal to those of natural circulation BWR. Experimental results showed that driving force of the natural circulation at the stability boundary was described as a function of heat flux and inlet subcooling independent of inlet restriction. In order to extend experimental database regarding thermal-hydraulic stability to different inlet restriction, numerical analysis was carried out based on the homogeneous flow model. Stability maps in reference to the core inlet subcooling and heat flux were presented for various inlet restrictions using the above-mentioned function. Instability region during the inlet subcooling shifted to the higher inlet subcooling with increasing inlet restriction and became larger with increasing heat flux.

  13. Particle Loss Calculator – a new software tool for the assessment of the performance of aerosol inlet systems

    Directory of Open Access Journals (Sweden)

    S.-L. von der Weiden

    2009-09-01

    Full Text Available Most aerosol measurements require an inlet system to transport aerosols from a select sampling location to a suitable measurement device through some length of tubing. Such inlet systems must be optimized to minimize aerosol sampling artifacts and maximize sampling efficiency. In this study we introduce a new multifunctional software tool (Particle Loss Calculator, PLC that can be used to quickly determine aerosol sampling efficiency and particle transport losses due to passage through arbitrary tubing systems. The software employs relevant empirical and theoretical relationships found in established literature and accounts for the most important sampling and transport effects that might be encountered during deployment of typical, ground-based ambient aerosol measurements through a constant-diameter sampling probe. The software treats non-isoaxial and non-isokinetic aerosol sampling, aerosol diffusion and sedimentation as well as turbulent inertial deposition and inertial deposition in bends and contractions of tubing. This software was validated through comparison with experimentally determined particle losses for several tubing systems bent to create various diffusion, sedimentation and inertial deposition properties. As long as the tube geometries are not "too extreme", agreement is satisfactory. We discuss the conclusions of these experiments, the limitations of the software and present three examples of the use of the Particle Loss Calculator in the field.

  14. Particle Loss Calculator – a new software tool for the assessment of the performance of aerosol inlet systems

    Directory of Open Access Journals (Sweden)

    S.-L. von der Weiden

    2009-04-01

    Full Text Available Most aerosol measurements require an inlet system to transport aerosols from a select sampling location to a suitable measurement device through some length of tubing. Such inlet systems must be optimized to minimize aerosol sampling artifacts and maximize sampling efficiency. In this study we introduce a new multifunctional software tool (Particle Loss Calculator, PLC that can be used to quickly determine aerosol sampling efficiency and particle transport losses due to passage through arbitrary tubing systems. The software employs relevant empirical and theoretical relationships found in established literature and accounts for the most important sampling and transport effects that might be encountered during deployment of typical, ground-based ambient aerosol measurements. The software treats non-isoaxial and non-isokinetic aerosol sampling, aerosol diffusion and sedimentation as well as turbulent inertial deposition and inertial deposition in bends and contractions of tubing. This software was validated through comparison with experimentally determined particle losses for several tubing systems bent to create various diffusion, sedimentation and inertial deposition properties. As long as the tube geometries are not "too extreme", agreement is satisfactory. We discuss the conclusions of these experiments, the limitations of the software and present three examples of the use of the Particle Loss Calculator in the field.

  15. Monitoring the Topography of a Dynamic Tidal Inlet Using UAV Imagery

    Directory of Open Access Journals (Sweden)

    Nathalie Long

    2016-05-01

    Full Text Available Unmanned Aerial Vehicles (UAVs are being increasingly used to monitor topographic changes in coastal areas. Compared to Light Detection And Ranging (LiDAR data or Terrestrial Laser Scanning data, this solution is low-cost and easy to use, while allowing the production of a Digital Surface Model (DSM with a similar accuracy. Three campaigns were carried out within a three-month period at a lagoon-inlet system (Bonne-Anse Bay, La Palmyre, France, with a flying wing (eBee combined with a digital camera. Ground Control Points (GCPs, surveyed by the Global Navigation Satellite System (GNSS and post-processed by differential correction, allowed georeferencing DSMs. Using a photogrammetry process (Structure From Motion algorithm, DSMs and orthomosaics were produced. The DSM accuracy was assessed against the ellipsoidal height of a GNSS profile and Independent Control Points (ICPs and the root mean square discrepancies were about 10 and 17 cm, respectively. Compared to traditional topographic surveys, this solution allows the accurate representation of bedforms with a wavelength of the order of 1 m and a height of 0.1 m. Finally, changes identified between both main campaigns revealed erosion/accretion areas and the progradation of a sandspit. These results open new perspectives to validate detailed morphological predictions or to parameterize bottom friction in coastal numerical models.

  16. Computer Graphic Design Using Auto-CAD and Plug Nozzle Research

    Science.gov (United States)

    Rogers, Rayna C.

    2004-01-01

    The purpose of creating computer generated images varies widely. They can be use for computational fluid dynamics (CFD), or as a blueprint for designing parts. The schematic that I will be working on the summer will be used to create nozzles that are a part of a larger system. At this phase in the project, the nozzles needed for the systems have been fabricated. One part of my mission is to create both three dimensional and two dimensional models on Auto-CAD 2002 of the nozzles. The research on plug nozzles will allow me to have a better understanding of how they assist in the thrust need for a missile to take off. NASA and the United States military are working together to develop a new design concept. On most missiles a convergent-divergent nozzle is used to create thrust. However, the two are looking into different concepts for the nozzle. The standard convergent-divergent nozzle forces a mixture of combustible fluids and air through a smaller area in comparison to where the combination was mixed. Once it passes through the smaller area known as A8 it comes out the end of the nozzle which is larger the first or area A9. This creates enough thrust for the mechanism whether it is an F-18 fighter jet or a missile. The A9 section of the convergent-divergent nozzle has a mechanism that controls how large A9 can be. This is needed because the pressure of the air coming out nozzle must be equal to that of the ambient pressure other wise there will be a loss of performance in the machine. The plug nozzle however does not need to have an A9 that can vary. When the air flow comes out it can automatically sense what the ambient pressure is and will adjust accordingly. The objective of this design is to create a plug nozzle that is not as complicated mechanically as it counterpart the convergent-divergent nozzle.

  17. Comparison of Chip Inlet Geometry in Microfluidic Devices for Cell Studies

    Directory of Open Access Journals (Sweden)

    Yung-Shin Sun

    2016-06-01

    Full Text Available Micro-fabricated devices integrated with fluidic components provide an in vitro platform for cell studies best mimicking the in vivo micro-environment. These devices are capable of creating precise and controllable surroundings of pH value, temperature, salt concentration, and other physical or chemical stimuli. Various cell studies such as chemotaxis and electrotaxis can be performed by using such devices. Moreover, microfluidic chips are designed and fabricated for applications in cell separations such as circulating tumor cell (CTC chips. Usually, there are two most commonly used inlets in connecting the microfluidic chip to sample/reagent loading tubes: the vertical (top-loading inlet and the parallel (in-line inlet. Designing this macro-to-micro interface is believed to play an important role in device performance. In this study, by using the commercial COMSOL Multiphysics software, we compared the cell capture behavior in microfluidic devices with different inlet types and sample flow velocities. Three different inlets were constructed: the vertical inlet, the parallel inlet, and the vertically parallel inlet. We investigated the velocity field, the flow streamline, the cell capture rate, and the laminar shear stress in these inlets. It was concluded that the inlet should be designed depending on the experimental purpose, i.e., one wants to maximize or minimize cell capture. Also, although increasing the flow velocity could reduce cell sedimentation, too high shear stresses are thought harmful to cells. Our findings indicate that the inlet design and flow velocity are crucial and should be well considered in fabricating microfluidic devices for cell studies.

  18. Long-Term Ecological Research (LTER) Climate Data with Water Parameters from North Inlet Meteorological Station, North Inlet Estuary, Georgetown, South Carolina: 1982-1996.

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — Meteorological data with water parameters were collected on an hourly basis from June 3, 1982 through April 29, 1996 in the North Inlet Estuary, Georgetown County,...

  19. North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

  20. Phosphorus mass balance in a highly eutrophic semi-enclosed inlet near a big metropolis: a small inlet can contribute towards particulate organic matter production.

    Science.gov (United States)

    Asaoka, Satoshi; Yamamoto, Tamiji

    2011-01-01

    Terrigenous loading into enclosed water bodies has been blamed for eutrophic conditions marked by massive algal growth and subsequent hypoxia due to decomposition of dead algal cells. This study aims to describe the eutrophication and hypoxia processes in a semi-enclosed water body lying near a big metropolis. Phosphorus mass balance in a small inlet, Ohko Inlet, located at the head of Hiroshima Bay, Japan, was quantified using a numerical model. Dissolved inorganic phosphorous inflow from Kaita Bay next to the inlet was five times higher than that from terrigenous load, which may cause an enhancement of primary production. Therefore, it was concluded that not only the reduction of material load from the land and the suppression of benthic flux are needed, but also reducing the inflow of high phosphorus and oxygen depleted water from Kaita Bay will form a collective alternative measure to remediate the environmental condition of the inlet.