Development of a Gas-Fed Pulse Detonation Engine

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Viv
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Development of a Gas-Fed Pulse Detonation Engine

Post by Viv » Fri Jul 04, 2008 7:10 pm

This is a NASA project to produce a research engine but the topic is general enough to pick up the basics for those who are interested

http://trs.nis.nasa.gov/archive/0000058 ... 211412.pdf

The above PDF is just over 45 megs so you may want to check up on your download cap if your one of our antipodal chums but I have included an extract of the first two page introduction below so you have some thing to read while the main document is downloading

1. INTRODUCTION
Pulsed detonation architectures have the potential to revolutionize aerospace propulsion and power
systems. This assertion is derived from the unique performance gains associated with unsteady reacting
flow effects and from the cost reductions associated with a highly simplified design configuration. Conse-
quently, there is considerable interest in obtaining an accurate assessment of representative performance
and cost benefits.
It should be noted that there are two fundamental architectural classifications for pulse detonation
engines (PDEs). That is, they can either obtain air from the surrounding atmosphere or acquire an oxidizer
from onboard storage tanks. In the former case, PDEs represent an attractive low-cost alternative to turbo-
jets based on their potential for surpassing intrinsic limits on scalability, operating range, efficiency, and
manufacturing costs. In the latter case, the device is referred to as a pulse detonation rocket engine (PDRE).
Generally speaking, PDEs operate on an intermittent cycle by filling a chamber with reactants and
inducing ignition in an energetic fashion such that a combustion detonation wave is rapidly established.
The high propagation speed of the detonation wave implies orders-of-magnitude increase in combustion
rates relative to the deflagration mode, and the chemical energy is completely released within a very nar-
row region behind the leading shock wave. As a result, the combustion process takes place at nearly con-
stant volume, which yields a higher postcombustion temperature (i.e., higher performance or specific
impulse (I
sp)) than a constant pressure process). The detonation wave has the added benefit of attaining a
higher peak pressure.
In fact, contemporary interest in PDREs arises primarily from advantages that accrue from the
significant combustion pressure rise developed by the detonation process. Because PDREs do not require
extreme precompression of the working fluid to fill the chamber, it should be possible to eliminate the need
for large and heavy turbopumps. This potential advantage must be carefully assessed, of course, in view of
the added requirement for fast-acting robust valves. Furthermore, the wide throttling range of a PDRE
should not be ignored as a favorable attribute since it can play an important role in many mission scenarios.
Although PDREs are expected to achieve greater I
sp (due to the higher peak temperature) and
greater design simplicity (due to the relaxed turbopump requirement), it is not yet clear whether they will
prove superior to conventional rocket engines from a systems point of view. Basic scientific feasibility has
been clearly established in several experimental and theoretical studies, as noted in recently published
review articles,1–3 but the unsteady operational attributes of PDEs complicate their analysis when includ-
ing nonideal effects, and it is difficult to make the needed system level assessments.

Surely, significant strides are being made with respect to the development of design strategies and
performance optimization,4–9 but it should be recognized that they are still at an early stage of develop-
ment. Furthermore, there are critical operational issues that must be addressed before the PDE concept will
ever be realized in practice, and reliable empirical data is badly needed.
A number of private companies are engaged in the design and development of various prototype
engines to address technical uncertainties and reduce risk, but the acquired data are not widely dissemi-
nated due to proprietary concerns. Therefore, a critical need exists for highly instrumented laboratory
research engines that will permit the establishment of an empirical database, which can be widely dissemi-
nated throughout industry, government, and academia. The Naval Postgraduate School and the Air Force
Research Laboratory at Wright-Patterson Air Force Base (AFB), for instance, have each built research
engines and initiated fundamental research programs in order to have an independent source of empirical
data.10,11 This Technical Publication describes the development of a low-cost gas-fed pulse detonation
research engine, which is intended to serve in a similar capacity at the NASA Marshall Space Flight Center
(MSFC)."

Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke

Viv's blog

Monsieur le commentaire

PyroJoe
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Re: Development of a Gas-Fed Pulse Detonation Engine

Post by PyroJoe » Mon Oct 11, 2010 4:04 pm

A useful Schelkin spiral illustration from the above source:



A belated thanks Viv for sharing this one.
Attachments
spiral.jpg

Viv
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Re: Development of a Gas-Fed Pulse Detonation Engine

Post by Viv » Mon Oct 11, 2010 5:07 pm

A belated "your Welcome" ;-)

Viv
"Sometimes the lies you tell are less frightening than the loneliness you might feel if you stopped telling them" Brock Clarke

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metiz
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Re: Development of a Gas-Fed Pulse Detonation Engine

Post by metiz » Fri Oct 15, 2010 10:01 pm

"pulse detonation engine theory and concepts" (ramjet, scramjet and PDE - an introduction)
"analysis of the pulse detonation engine" (decribes sensor type, placements etc in a PDE engine)
"applications of detonation to propulsion - a review" (Thesis paper on the subject)
"strategies for pulsed detonation engine performance optimization" (study on DDT)
"preliminary modeling of pulse detonation rocket engines" (perspective view on detonation engines)
"multilevel analysis of pulse detonation engines"(ditto)
"modeling of pulsed detonation engine operation" (a model for the performance of air-breathing pulse detonation engines)
"operation of a jp10/air pulse detonation engine" (hydrocarbon fuelled pulse detonation engine analysis)
"detonation initiation studies and performance results for pulsed detonation engine applications" (ditto)
"integrated pulse detonation propulsion and magnetohydrodynamic power" (scientific and technical aerospace reports)

Reference list of the original document posted here used for google searches
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ace_fedde
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Re: Development of a Gas-Fed Pulse Detonation Engine

Post by ace_fedde » Mon Oct 18, 2010 10:48 am

O.k. let's make this topic a stickey one!
Your scepticism is fuel for my brain.

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