Transcript Pulse Jet Engine

Pulse Jet Engine
Jeff Dennen
Justin Marriott
Brian Melo
Matt Skillin
Project
 Our project is to design and build a pulse jet engine
 We plan to make the engine as efficient as possible with the
budget that we have set.

BM
Plan
 We are first going to create different designs and then do a
design matrix to determine the best design
 We are then going to do hand calculations to determine
the best way to design the jet engine to provide maximum
thrust.
 We then are going to create a Solidworks model
 Finally we will build and test against our hand calculations.

JD
What is a pulse jet engine?
 A Pulse Jet is an engine that works on combustion in phases
called pulses
 These engines are usually mad using no moving parts
 Pulse jets were used by the German’s in WWII, they were
used as a bomb called the “buzz bomb” because of the sound
of the bomb made.

JM
How does it work?
 The primary effect behind the function of a pulsejet is the
fact that gases are compressible and tend to act like a
spring.
 This “springiness” is crucial to the way a pulsejet draws in
a fresh mixture of air and fuel then expels the hot
burning gasses that are generated when that fuel is
ignited.
 Copyright 2004, 2005 Bruce Simpson.
http://www.pulsejetbook.com

MS
Kinds of Pulse Jets
 Valve:
 Pedal or spring valve construction
 Harder to build
 More Expansive
 Valve-less:
 No moving parts
 Easier to build
 Cheaper

JM
Calculations
Thrust
ENGLISH (pounds / inches)
Metric (Kg / cm)
100
45
Exhaust Pipe Diameter B
5.64332648
14.26219894
Tailpipe Length C
62.37815104
157.8325874
Combustion Chamber Length D
12.47563021
31.56651749
Exhaust Cone Length E
12.47563021
31.56651749
Exhaust Pipe Length F
37.42689063
94.69955246
Combustion Chamber Dia (G) For Following Valve Type
Petal Valve System
11.28665296
28.52439787
High Efficiency Petal Valve
8.922882628
22.55051654
Valve Grid
8.226491308
20.79054898
Valve Head Length (Tuned)
9.356722657
23.67488812
Estimated Frequency
81.27845913
Low
81.59151547
Low
87.53064829
High
87.86778589
High
Bibliography
 Simpson Bruce “The Enthusiasts' Guide to Pulsejet
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Engines”
http://www.aardvark.co.nz/pjet/
http://www.zachmiers.com/pulsejetbook/
http://www.pulse-jets.com/
Roy, Gabriel “Combustion processes in propulsion
control, noise, and pulse detonation”
o MS
Questions?