Intake Flow Analysis of a Pulsed Detonation Engine

Intake Flow Analysis of a Pulsed Detonation Engine PDF Author: Joshua Amadeus Strafaccia
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 78

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Book Description
A CFD program is converted and modified to explore unsteady flow within the intake system of a pulse detonation engine (PDE). Using a quasi-one-dimensional approach the program provides insight into the unsteady nature of localized equivalence ratios to include their effects on PDE performance. The original FORTRAN program is converted into the MATLAB architecture, taking full advantage of user availability and post processing convenience. The converted program was validated against the original program and modified to include a primitive intake manifold system with a single fuel injector located approximately 10 feet upstream of the primary intake valve. Constant fuel mass flow rate at the injector end creates local variations in equivalence ratio throughout the PDE that may have significant impact on overall engine performance. The results of the current thesis research suggest that performance effects of up to 21% can be attributed to non-uniform fuel distribution throughout the detonation process and are most prevalent at lower frequencies and fill ratios.

Intake Flow Analysis of a Pulsed Detonation Engine

Intake Flow Analysis of a Pulsed Detonation Engine PDF Author: Joshua Amadeus Strafaccia
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 78

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Book Description
A CFD program is converted and modified to explore unsteady flow within the intake system of a pulse detonation engine (PDE). Using a quasi-one-dimensional approach the program provides insight into the unsteady nature of localized equivalence ratios to include their effects on PDE performance. The original FORTRAN program is converted into the MATLAB architecture, taking full advantage of user availability and post processing convenience. The converted program was validated against the original program and modified to include a primitive intake manifold system with a single fuel injector located approximately 10 feet upstream of the primary intake valve. Constant fuel mass flow rate at the injector end creates local variations in equivalence ratio throughout the PDE that may have significant impact on overall engine performance. The results of the current thesis research suggest that performance effects of up to 21% can be attributed to non-uniform fuel distribution throughout the detonation process and are most prevalent at lower frequencies and fill ratios.

Detonation Control for Propulsion

Detonation Control for Propulsion PDF Author: Jiun-Ming Li
Publisher: Springer
ISBN: 3319689061
Category : Technology & Engineering
Languages : en
Pages : 246

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Book Description
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.

Investigation of Pulse Detonation Engines ; Theory, Design, and Analysis

Investigation of Pulse Detonation Engines ; Theory, Design, and Analysis PDF Author: Jeff Vizcaino
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 510

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Book Description
"Detonation and constant volume combustion has been known to the scientific community for some time but only recently has active research been done into its applications. Detonation based engines have received much attention in the last two decades because of its simple design and potential benefits to the aerospace industry. It is the goal of this study to provide a background into detonation theory and application and establish the basis for future detonation based research at Embry-Riddle Aeronautical University. In this paper we will discuss the experimental aspects of building, testing, and analysis of a pulsed detonation tube including the development of a pulsed detonation testbed and analysis via computational fluid dynamics."--Leaf iv.

A Study of Deflagration to Detonation Transition in a Pulsed Detonation Engine

A Study of Deflagration to Detonation Transition in a Pulsed Detonation Engine PDF Author: David Michael Chapin
Publisher:
ISBN:
Category : Propulsion systems
Languages : en
Pages :

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Book Description
A Pulse Detonation Engine (PDE) is a propulsion device that takes advantage of the pressure rise inherent to the efficient burning of fuel-air mixtures via detonations. Detonation initiation is a critical process that occurs in the cycle of a PDE. A practical method of detonation initiation is Deflagration-to-Detonation Transition (DDT), which describes the transition of a subsonic deflagration, created using low initiation energies, to a supersonic detonation. This thesis presents the effects of obstacle spacing, blockage ratio, DDT section length, and airflow on DDT behavior in hydrogen-air and ethylene-air mixtures for a repeating PDE. These experiments were performed on a 2 diameter, 40 long, continuous-flow PDE located at the General Electric Global Research Center in Niskayuna, New York. A fundamental study of experiments performed on a modular orifice plate DDT geometry revealed that all three factors tested (obstacle blockage ratio, length of DDT section, and spacing between obstacles) have a statistically significant effect on flame acceleration. All of the interactions between the factors, except for the interaction of the blockage ratio with the spacing between obstacles, were also significant. To better capture the non-linearity of the DDT process, further studies were performed using a clear detonation chamber and a high-speed digital camera to track the flame chemiluminescence as it progressed through the PDE. Results show that the presence of excess obstacles, past what is minimally required to transition the flame to detonation, hinders the length and time to transition to detonation. Other key findings show that increasing the mass flow-rate of air through the PDE significantly reduces the run-up time of DDT, while having minimal effect on run-up distance. These experimental results provided validation runs for computational studies. In some cases as little as 20% difference was seen. The minimum DDT length for 0.15 lb/s hydrogen-air studies was 8 L/D from the spark location, while for ethylene it was 16 L/D. It was also observed that increasing the airflow rate through the tube from 0.1 to 0.3 lbs/sec decreased the time required for DDT by 26%, from 3.9 ms to 2.9 ms.

Numerical Study of Chemically Reacting Viscous Flow Relevant to Pulsed Detonation Engines

Numerical Study of Chemically Reacting Viscous Flow Relevant to Pulsed Detonation Engines PDF Author: Tae-Hyeong Yi
Publisher:
ISBN: 9780542449628
Category : Aerospace engineering
Languages : en
Pages :

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Book Description
A computational fluid dynamics code for two-dimensional, multi-species, laminar Navier-Stokes equations is developed to simulate a recently proposed engine concept for a pulsed detonation based propulsion system and to investigate the feasibility of the engine of the concept. The governing equations that include transport phenomena such as viscosity, thermal conduction and diffusion are coupled with chemical reactions. The gas is assumed to be thermally perfect and in chemically non-equilibrium. The stiffness due to coupling the fluid dynamics and the chemical kinetics is properly taken care of by using a time-operator splitting method and a variable coefficient ordinary differential equation solver. A second-order Roe scheme with a minmod limiter is explicitly used for space descretization, while a second-order, two-step Runge-Kutta method is used for time descretization. In space integration, a finite volume method and a cell-centered scheme are employed. The first-order derivatives in the equations of transport properties are discretized by a central differencing with Green's theorem. Detailed chemistry is involved in this study. Two chemical reaction mechanisms are extracted from GRI-Mech, which are forty elementary reactions with thirteen species for a hydrogen-air mixture and twenty-seven reactions with eight species for a hydrogen-oxygen mixture. The code is ported to a high-performance parallel machine with Message-Passing Interface. Code validation is performed with chemical kinetic modeling for a stoichiometric hydrogen-air mixture, an one-dimensional detonation tube, a two-dimensional, inviscid flow over a wedge and a viscous flow over a flat plate. Detonation is initiated using a numerically simulated arc-ignition or shock-induced ignition system. Various freestream conditions are utilized to study the propagation of the detonation in the proposed concept of the engine. Investigation of the detonation propagation is performed for a pulsed detonation rocket and a supersonic combustion chamber. For a pulsed detonation rocket case, the detonation tube is embedded in a mixing chamber where an initiator is added to the main detonation chamber. Propagating detonation waves in a supersonic combustion chamber is investigated for one- and two-dimensional cases. The detonation initiated by an arc and a shock wave is studied in the inviscid and viscous flow, respectively. Various features including a detonation-shock interaction, a detonation diffraction, a base flow and a vortex are observed.

Multiphase Flow Modeling and Analysis of Phased Filling Process for Pulsed Detonation Engine

Multiphase Flow Modeling and Analysis of Phased Filling Process for Pulsed Detonation Engine PDF Author: Nirmal Kumar Umapathy
Publisher:
ISBN:
Category :
Languages : en
Pages : 92

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Book Description
Filling of reactants into a pulsed detonation engine (PDE) should be carried out quickly because any lengthening of the fill time will lead to an increased cycle time. The fill process and, the purge process constitutes a large proportion of time in a cycle. The purpose of this research was to improve the time of fill by implementing various injection geometries in two injection schemes with five different premixed stoichiometric fuel-air mixture injected at wide range of velocity. The different configurations examined were end wall injection, side wall injection with ports angled and normal to the flow direction and staggered side wall injection. The two injection schemes were simultaneous injection and phased injection through side wall ports. The fuel choices were biogas, hydrogen, methane, propane and octane, all in the gaseous state. The oxidizer considered was air and pre-mixed with fuels. Numerical modeling was carried out using the commercial software Fluent as the mesh generation tool and flow solver, solving the Reynolds-averaged Navier-Stokes equations with a k-[epsilon] turbulence model. The normal sidewall injection yielded the shortest fill time while staggered injection resulted in good fill uniformity. Angled upstream injection resulted in the most advantage with low time of fill, good fill uniformity and moderate spillage. Future improvements were suggested.

Parametric Cycle Analysis for Pulse Detonation Engines

Parametric Cycle Analysis for Pulse Detonation Engines PDF Author: Haider Hekiri
Publisher:
ISBN: 9780542448836
Category : Aerospace engineering
Languages : en
Pages :

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Book Description
The performance of an ejector-driven pulse detonation engine (PDE) with an afterburner is analytically estimated. In the analysis, the PDE was modeled as a straight tube, closed at the front end and open at the other. A detonation wave starts to travel after it is ignited at the closed end, causing a Chapman-Jouguet detonation wave followed by a Taylor rarefaction to travel to the open end. At that point, rarefaction waves are reflected back to the closed end. The result is a high thrust due to both the primary and secondary flows of the ejector-driven PDE. A theoretical analysis is made to determine the average thrust density and the impulse density per cycle of the primary flow. The mixed flow of the PDE tube and the ejector is then subjected to afterburning. The overall engine performance was eventually derived.

Коммунист: календарь-справоčник 1978

Коммунист: календарь-справоčник 1978 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 315

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Book Description


A Computational Study of Thermo-fluid Dynamics of Pulse Detonation Engines

A Computational Study of Thermo-fluid Dynamics of Pulse Detonation Engines PDF Author: Alberto Dávila Urresti
Publisher:
ISBN:
Category : Computational fluid dynamics
Languages : en
Pages : 172

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Book Description
"The purpose of this thesis is to use a transient Computational Fluid Dynamics computer code written in FORTRAN 90 for full reaction kinetics, to perform an analysis of the physical processes and chemical phenomena occurring on a single cycle of an ideal Pulse Detonation Engine (PDE) using a stoichiometric mixture of H2 and O2."--Leaf iii.

A Multidisciplinary Study of Pulse Detonation Engine Propulsion

A Multidisciplinary Study of Pulse Detonation Engine Propulsion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The Penn State-led MURI effort on Pulse Detonation Engine (PDE) Research is detailed in this report. The multidisciplinary research effort brought together a team of leading researchers in the areas of the initiation and propagation of detonations, liquid hydrocarbon spray detonation, combustion chemistry, injector and flow field mixing, and advanced diagnostics to study the fundamental phenomena of importance under both static and dynamic conditions representative of actual pulse detonation engine operation. The team focused its effort on conducting key experiments and analysis in the areas of (a) Fundamental Detonation Studies, (b) Injection, Mixing and Initiation, (c) Inlet-Combustor-Nozzle Performance, (d) Multi-Cycle Operation, and (e) Computer Simulation and Cycle Analysis. These study areas are five of seven topic areas that have been delineated by the Office of Naval Research (ONR) in their roadmap on pulse detonation engine research necessary for developing the technologies needed for the design of an air-breathing pulse detonation engine. The results obtained in these five study areas under this effort by researchers at Penn State, Caltech and Princeton University, coupled with the results of the effort by the sister MURI team led by the University of California at San Diego in some of the aforementioned study areas and in the remaining two study areas of (a) Diagnostics and Sensors, and (b) Dynamics and Control provide the foundation needed for the development of a PDE system. The overall success of the program stems from ONR led coordination that fostered collaboration between the two MURI research efforts and government laboratories and industry research through a series of progress workshops held at six-month intervals.