Download or read book Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector Nasa cr 2003 212191 National Aeronautics and Space Administr written by United States. National Aeronautics and Space Administration and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present NASA GRC-funded three-year research project is focused on studying PDE driven ejectors applicable to a hybrid Pulse Detonation/Turbofan Engine. The objective of the study is to characterize the PDE-ejector thrust augmentation. A PDE-ejector system has been designed to provide critical experimental data for assessing the performance enhancements possible with this technology. Completed tasks include demonstration of a thrust stand for measuring average thrust for detonation tube multi-cycle operation, and design of a 72-in.-long, 2.25-in.-diameter (ID) detonation tube and modular ejector assembly. This assembly will allow testing of both straight and contoured ejector geometries. Initial ejectors that have been fabricated are 72-in.-long-constant-diameter tubes (4-, 5-, and 6-in.-diameter) instrumented with high-frequency pressure transducers. The assembly has been designed such that the detonation tube exit can be positioned at various locations within the ejector tube. PDE-ejector system experiments with gaseous ethylene/ nitrogen/oxygen propellants will commence in the very near future. The program benefits from collaborations with Prof. Merkle of University of Tennessee whose PDE-ejector analysis helps guide the experiments. The present research effort will increase the TRL of PDE-ejectors from its current level of 2 to a level of 3. Santoro, Robert J. and Pal, Sibtosh Glenn Research Center NASA/CR-2003-212191, NAS 1.26:212191, E-13794

Download or read book Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector written by and published by . This book was released on 2003 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Model of Pulsed Ejector Thrust Augmentation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-29 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple model of thrust augmentation from a pulsed source is described. In the model it is assumed that the flow into the ejector is quasi-steady, and can be calculated using potential flow techniques. The velocity of the flow is related to the speed of the starting vortex ring formed by the jet. The vortex ring properties are obtained from the slug model, knowing the jet diameter, speed and slug length. The model, when combined with experimental results, predicts an optimum ejector radius for thrust augmentation. Data on pulsed ejector performance for comparison with the model was obtained using a shrouded Hartmann-Sprenger tube as the pulsed jet source. A statistical experiment, in which ejector length, diameter, and nose radius were independent parameters, was performed at four different frequencies. These frequencies corresponded to four different slug length to diameter ratios, two below cut-off, and two above. Comparison of the model with the experimental data showed reasonable agreement. Maximum pulsed thrust augmentation is shown to occur for a pulsed source with slug length to diameter ratio equal to the cut-off value.Wilson, Jack and Deloof, Richard L. (Technical Monitor)Glenn Research CenterTHRUST AUGMENTATION; MATHEMATICAL MODELS; FLOW VELOCITY; HARTMANN-SPRENGER TUBES; VORTEX RINGS; PULSED JET ENGINES; EJECTORS

Download or read book Parametric Investigation of Thrust Augmentation by Ejectors on a Pulsed Detonation Tube written by Jack Wilson and published by BiblioGov. This book was released on 2013-08 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A parametric investigation has been made of thrust augmentation of a 1 in. diameter pulsed detonation tube by ejectors. A set of ejectors was used which permitted variation of the ejector length, diameter, and nose radius, according to a statistical design of experiment scheme. The maximum augmentation ratios for each ejector were fitted using a polynomial response surface, from which the optimum ratios of ejector diameter to detonation tube diameter, and ejector length and nose radius to ejector diameter, were found. Thrust augmentation ratios above a factor of 2 were measured. In these tests, the pulsed detonation device was run on approximately stoichiometric air-hydrogen mixtures, at a frequency of 20 Hz. Later measurements at a frequency of 40 Hz gave lower values of thrust augmentation. Measurements of thrust augmentation as a function of ejector entrance to detonation tube exit distance showed two maxima, one with the ejector entrance upstream, and one downstream, of the detonation tube exit. A thrust augmentation of 2.5 was observed using a tapered ejector.

Download or read book An Experimental Study of a Three Dimensional Thrust Augmenting Ejector Using Laser Doppler Velocimetry written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-17 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow field measurements were obtained in a three-dimensional thrust augmenting ejector using laser Doppler velocimetry and hot wire anemometry. The primary nozzle, segmented into twelve slots of aspect ratio 3.0, was tested at a pressure ratio of 1.15. Results are presented on the mean velocity, turbulence intensity, and Reynolds stress progressions in the mixing chamber of the constant area ejector. The segmented nozzle was found to produce streamwise vortices that may increase the mixing efficiency of the ejector flow field. Compared to free jet results, the jet development is reduced by the presence of the ejector walls. The resulting thrust augmentation ratio of this ejector was also calculated to be 1.34. Storms, Bruce Lowell Unspecified Center EJECTORS; FLOW MEASUREMENT; LASER DOPPLER VELOCIMETERS; REYNOLDS STRESS; THREE DIMENSIONAL FLOW; THRUST AUGMENTATION; TURBULENCE EFFECTS; VORTICES; ASPECT RATIO; EXHAUST VELOCITY; HOT-WIRE ANEMOMETERS; NOZZLE DESIGN; PRESSURE RATIO; V/STOL AIRCRAFT...

Download or read book MULTIPLE CYCLE SIMULATION OF A PULSE DETONATION ENGINE EJECTOR NASA TM 2002 211888 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION O written by and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiple Cycle Simulation of a Pulse Detonation Engine Ejector written by S. Yungster and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Model of Pulsed Ejector Thrust Augmentation written by and published by . This book was released on 2003 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Ejector Geometry on Thrust Augmentation for Pulse Detonation Engine Ejector Systems written by Ra'fat Shehadeh and published by . This book was released on 2007 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: The major potential advantages of the PDE-ejector include reduced costs due to the reduced engine weight, along with improved specific fuel consumption and specific power inherent in the incorporation of a PDE component.

Download or read book Multiple cycle Simulation of a Pulse Detonation Engine Ejector written by Shaye Yungster and published by . This book was released on 2002 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thrust Augmentation Study of High Performance Ejectors written by John E. Minardi and published by . This book was released on 1983 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: A technique is developed for determining a representative value of the maximum efficiency that can be achieved with high performance ejectors when operating on the supersonic solution branch of an ejector. These efficiencies are used to calculate thrust augmentation for an ejector over a wide range of parameters including operation with a hypothetical engine. Reasonable values of thrust augmentation can be achieved at low subsonic flight mach numbers. However, at flight Mach numbers near one, little or not thrust augmentation was found. At supersonic flight Mach numbers, thrust augmentation was achieved. Basic studies indicated that the effects of temperature was opposite at subsonic and supersonic flight Mach numbers. Thrust augmentation decreased with increasing temperature at subsonic Mach number sand increased with increasing temperature at supersonic Mach numbers.

Download or read book A Control Volume Method for Analysis of Unsteady Thrust Augmenting Ejector Flows written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for predicting transient thrust augmenting ejector characteristics is presented. The analysis blends classic self-similar turbulent jet descriptions with a control volume mixing region discretization to solicit transient effects in a new way. Division of the ejector into an inlet, diffuser, and mixing region corresponds with the assumption of viscous-dominated phenomenon in the latter. Inlet and diffuser analyses are simplified by a quasi-steady analysis, justified by the assumptions that pressure is the forcing function in those regions. Details of the theoretical foundation, the solution algorithm, and sample calculations are given. Drummond, Colin K. Unspecified Center COMPUTATIONAL FLUID DYNAMICS; COMPUTERIZED SIMULATION; EJECTORS; FINITE VOLUME METHOD; MATHEMATICAL MODELS; THRUST AUGMENTATION; TURBULENT JETS; UNSTEADY FLOW; ALGORITHMS; INLET FLOW; PREDICTION ANALYSIS TECHNIQUES; REAL TIME OPERATION...

Download or read book Detonation Control for Propulsion written by Jiun-Ming Li and published by Springer. This book was released on 2017-12-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the latest developments in detonation engines for aerospace propulsion, with a focus on the rotating detonation engine (RDE). State-of-the-art research contributions are collected from international leading researchers devoted to the pursuit of controllable detonations for practical detonation propulsion. A system-level design of novel detonation engines, performance analysis, and advanced experimental and numerical methods are covered. In addition, the world’s first successful sled demonstration of a rocket rotating detonation engine system and innovations in the development of a kilohertz pulse detonation engine (PDE) system are reported. Readers will obtain, in a straightforward manner, an understanding of the RDE & PDE design, operation and testing approaches, and further specific integration schemes for diverse applications such as rockets for space propulsion and turbojet/ramjet engines for air-breathing propulsion. Detonation Control for Propulsion: Pulse Detonation and Rotating Detonation Engines provides, with its comprehensive coverage from fundamental detonation science to practical research engineering techniques, a wealth of information for scientists in the field of combustion and propulsion. The volume can also serve as a reference text for faculty and graduate students and interested in shock waves, combustion and propulsion.

Download or read book Effects of Fuel Distribution on Detonation Tube Performance written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-30 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pulse detonation engine (PDE) uses a series of high frequency intermittent detonation tubes to generate thrust. The process of filling the detonation tube with fuel and air for each cycle may yield non-uniform mixtures. Lack of mixture uniformity is commonly ignored when calculating detonation tube thrust performance. In this study, detonation cycles featuring idealized non-uniform H2/air mixtures were analyzed using the SPARK two-dimensional Navier-Stokes CFD code with 7-step H2/air reaction mechanism. Mixture non-uniformities examined included axial equivalence ratio gradients, transverse equivalence ratio gradients, and partially fueled tubes. Three different average test section equivalence ratios (phi), stoichiometric (phi = 1.00), fuel lean (phi = 0.90), and fuel rich (phi = 1.10), were studied. All mixtures were detonable throughout the detonation tube. It was found that various mixtures representing the same test section equivalence ratio had specific impulses within 1 percent of each other, indicating that good fuel/air mixing is not a prerequisite for optimal detonation tube performance.Perkins, Hugh DouglasGlenn Research CenterNAVIER-STOKES EQUATION; PULSE DETONATION ENGINES; FUEL COMBUSTION; FUEL-AIR RATIO; DETONATION; DETONABLE GAS MIXTURES; DETONATION WAVES; TEST CHAMBERS; SPECIFIC IMPULSE; THRUST; NONUNIFORMITY; COMPUTATIONAL FLUID DYNAMICS

Download or read book MULTIPLE CYCLE SIMULATION OF A PULSE DETONATION ENGINE EJECTOR NASA written by and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impact of Dissociation and Sensible Heat Release on Pulse Detonation and Gas Turbine Engine Performance written by and published by . This book was released on 2001 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: