Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector ... Nasa/cr--2003-212191 ... National Aeronautics and Space Administr

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector ... Nasa/cr--2003-212191 ... National Aeronautics and Space Administr PDF Author: United States. National Aeronautics and Space Administration
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Languages : en
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Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector ... Nasa/cr--2003-212191 ... National Aeronautics and Space Administr

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector ... Nasa/cr--2003-212191 ... National Aeronautics and Space Administr PDF Author: United States. National Aeronautics and Space Administration
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Languages : en
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Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721571031
Category :
Languages : en
Pages : 34

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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

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector

Thrust Augmentation Measurements Using a Pulse Detonation Engine Ejector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 24

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A Simple Model of Pulsed Ejector Thrust Augmentation

A Simple Model of Pulsed Ejector Thrust Augmentation PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720364979
Category :
Languages : en
Pages : 30

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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

Parametric Investigation of Thrust Augmentation by Ejectors on a Pulsed Detonation Tube

Parametric Investigation of Thrust Augmentation by Ejectors on a Pulsed Detonation Tube PDF Author: Jack Wilson
Publisher: BiblioGov
ISBN: 9781289277475
Category :
Languages : en
Pages : 24

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Book Description
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.

An Experimental Study of a Three-Dimensional Thrust Augmenting Ejector Using Laser Doppler Velocimetry

An Experimental Study of a Three-Dimensional Thrust Augmenting Ejector Using Laser Doppler Velocimetry PDF Author: National Aeronautics and Space Adm Nasa
Publisher:
ISBN: 9781731249487
Category :
Languages : en
Pages : 132

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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...

Multiple-cycle Simulation of a Pulse Detonation Engine Ejector ... Nasa/tm--2002-211888 ... National Aeronautics and Space Administration ... O

Multiple-cycle Simulation of a Pulse Detonation Engine Ejector ... Nasa/tm--2002-211888 ... National Aeronautics and Space Administration ... O PDF Author:
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Category :
Languages : en
Pages :

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Multiple-Cycle Simulation of a Pulse Detonation Engine Ejector

Multiple-Cycle Simulation of a Pulse Detonation Engine Ejector PDF Author: S. Yungster
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

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A Simple Model of Pulsed Ejector Thrust Augmentation

A Simple Model of Pulsed Ejector Thrust Augmentation PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 32

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Study of Ejector Geometry on Thrust Augmentation for Pulse Detonation Engine Ejector Systems

Study of Ejector Geometry on Thrust Augmentation for Pulse Detonation Engine Ejector Systems PDF Author: Ra'fat Shehadeh
Publisher:
ISBN: 9780549046615
Category :
Languages : en
Pages : 250

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Book Description
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.