Evaluation of Catalytic and Thermal Cracking in a JP-8 Fueled Pulsed Detonation Engine

2007 ◽  
Author(s):  
Timothy Helfrich ◽  
Frederick Schauer ◽  
Royce Bradley ◽  
John Hoke
Keyword(s):  
Thermal Cracking ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Detonation Engine

scholarly journals Adjoint-based optimisation of detonation initiation by a focusing shock wave

Shock Waves ◽  
2021 ◽  
Author(s):  
S. Bengoechea ◽  
J. Reiss ◽  
M. Lemke ◽  
J. Sesterhenn
Keyword(s):  
Shock Wave ◽  
Incident Shock ◽  
Incident Shock Wave ◽  
Detonation Initiation ◽  
Axisymmetric Nozzle ◽  
Exponential Factor ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Detonation Engine ◽  
Adjoint Approach

AbstractAn optimisation study of a shock-wave-focusing geometry is presented in this work. The configuration serves as a reliable and deterministic detonation initiator in a pulsed detonation engine. The combustion chamber consists of a circular pipe with one convergent–divergent axisymmetric nozzle, acting as a focusing device for an incoming shock wave. Geometrical changes are proposed to reduce the minimum shock wave strength necessary for a successful detonation initiation. For that purpose, the adjoint approach is applied. The sensitivity of the initiation to flow variations delivered by this method is used to reshape the obstacle’s form. The thermodynamics is described by a higher-order temperature-dependent polynomial, avoiding the large errors of the constant adiabatic exponent assumption. The chemical reaction of stoichiometric premixed hydrogen-air is modelled by means of a one-step kinetics with a variable pre-exponential factor. This factor is adapted to reproduce the induction time of a complex kinetics model. The optimisation results in a 5% decrease of the incident shock wave threshold for the successful detonation initiation.

Integrated Vehicle Comparison of Turbo-Ramjet Engine and Pulsed Detonation Engine

2002 ◽  
Vol 125 (1) ◽  
pp. 257-262 ◽  
Author(s):  
T. Kaemming
Keyword(s):  
Life Cycle Cost ◽  
High Speed ◽  
Fuel Efficiency ◽  
Pressure Rise ◽  
Propulsion System ◽  
Cross Sectional ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Large Matrix ◽  
Detonation Engine

The pulsed detonation engine (PDE) is a unique propulsion system that uses the pressure rise associated with detonations to efficiently provide thrust. A study was conducted under the direction of the NASA Langley Research Center to identify the flight applications that provide the greatest potential benefits when incorporating a PDE propulsion system. The study was conducted in three phases. The first two phases progressively screened a large matrix of possible applications down to three applications for a more in-depth, advanced design analysis. The three applications best suited to the PDE were (1) a supersonic tactical aircraft, (2) a supersonic strike missile, and (3) a hypersonic single-stage-to-orbit (SSTO) vehicle. The supersonic tactical aircraft is the focus of this paper. The supersonic, tactical aircraft is envisioned as a Mach 3.5 high-altitude reconnaissance aircraft with possible strike capability. The high speed was selected based on the perceived high-speed fuel efficiency benefits of the PDE. Relative to a turbo-ramjet powered vehicle, the study identified an 11% to 21% takeoff gross weight (TOGW) benefit to the PDE on the baseline 700 n.mi. radius mission depending on the assumptions used for PDE performance and mission requirements. The TOGW benefits predicted were a result of the PDE lower cruise specific fuel consumption (SFC) and lower vehicle supersonic drag. The lower vehicle drag resulted from better aft vehicle shaping, which was a result of better distribution of the PDE cross-sectional area. The reduction in TOGW and fuel usage produced an estimated 4% reduction in life cycle cost for the PDE vehicle. The study also showed that the simplicity of the PDE enables concurrent engineering development of the vehicle and engine.

scholarly journals Intake Flow Analysis of a Pulsed Detonation Engine

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Joshua A. Strafaccia ◽  
Semih M. Ölçmen ◽  
John L. Hoke ◽  
Daniel E. Paxson
Keyword(s):  
Fluid Dynamic ◽  
Flow Analysis ◽  
Engine Performance ◽  
Fuel Injector ◽  
Pulse Detonation ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Fill Fraction ◽  
Detonation Engine ◽  
Intake Flow

Unsteady flow within the intake system of a hydrogen–air pulse detonation engine (PDE) has been analyzed using a quasi-one-dimensional (Q1D) computational fluid dynamic (CFD) code. The analysis provides insight into the unsteady nature of localized equivalence ratios and their effects on PDE performance. For this purpose, a code originally configured to model the PDE tube proper was modified to include a 6.1 m long intake with a single fuel injector located approximately 3.05 m upstream of the primary intake valve. The results show that constant fuel mass flow rate injection from the injector creates large local variations in equivalence ratio throughout the PDE within a cycle. The effect of fill fraction on the engine performance is better described with the presence of the inlet model. However, the effect of ignition delay is shown to be better predicted with a model without the inlet.

Detonability of simple and representative components of pyrolysis products of kerosene: pulsed detonation engine application

Shock Waves ◽  
2005 ◽  
Vol 14 (4) ◽  
pp. 283-291 ◽  
Author(s):  
X. Rocourt ◽  
P. Gillard ◽  
F. Faubert ◽  
I. Sochet ◽  
P. Dagaut
Keyword(s):  
Pyrolysis Products ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Detonation Engine

Pulsed detonation engine - Possible application to low cost tactical missile and to space launcher

2001 ◽  
Author(s):  
Francois Falempin ◽  
Dominique Bouchaud ◽  
Bernard Forrat ◽  
Daniel Desbordes ◽  
Emeric Daniau
Keyword(s):  
Low Cost ◽  
Pulsed Detonation Engine ◽  
Pulsed Detonation ◽  
Detonation Engine ◽  
Space Launcher
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