1. Project Pulse-Jet Group 4
Jeffrey Dennen
Justin Marriott
Brian Melo
Matthew Skillin

2. What is Project Pulse–Jet?
is an analytical study of how a pulse-jet engine works.
Our Goals
To design, build and test a pulse-jet engine.
Plan of Action
Research and design a prototype of a pulse-jet engine.
Build the prototype based on our design.
Test the prototype against the theoretical analysis.

3. History of the pulsejet
The pulsejet engine was first invented in the early 1900 by a Swedish inventor Martin Wiberg
Paul Schmidt, who engineered the first production pulsejet during the Second World War with his flying bomb, the Argus V1.
Nicknamed the “buzz” bomb because of the low hum it admitted during flight.
Used by the Germans to bomb London from
Over 9,000 V-1 were fired on England during WW2
The pulsejet took a backseat in the engineering world when the turbofan jet engine was invented
Has returned to the engineering scene as
of late because of the interest in
Pulse Detonation Engines (PDE).

4. How does it work?
A pulsejet engine is a very simple jet engine consisting of very little to no moving parts. The combustion cycle comprises five or six phases: Induction, Compression, (in some engines) Fuel Injection, Ignition, Combustion, and Exhaust.
The rapidly expanding gasses exit out of the engine and as this happens a vacuum is created in the combustion chamber which pulls in a fresh new air charge fro m the atmosphere, and then the whole cycle repeats itself.

5. Combustion Cycle

7. Types of Pulse Jets There are two basic types of pulsejets.
valve or traditional pulsejet
valve-less pulsejet.
The Argus V1 Schmidt was a valve pulsejet
Most of the development work for the valve-less engines are done by two American engineers Lockwood and Hiller.
Types of Valves
Petal
High Efficiency Petal
Valve Grid

8. Design Research
The Lenoir cycle is an idealized thermodynamic cycle often used to model a pulse-jet engine.
Comprises of 3 cycles:
Heat added at constant volume.
Adiabatic Expansion.
Exhaust of the hot gasses at a constant pressure.
Thrust can be directly calibrated on the basis that
the cycle is completed over two working strokes.

9. Design Research C.E. Tharratt
Discovered a surprising result that the ratio of duct volume to effective length had a linear relationship to the maximum static thrust or:
V/L = F
This relationship has been compared to all known pulse-jets from the large V-1 “flying bomb” of over 500 lb. thrust to the miniature Dyna-jets of 4-5 lbs. thrust.
Thrust = 2.2 x Cross-Sectional area or F = 2.2A

10. Sample Calculations .

11. Pulse-Jet Body Design

12. Pulse-Jet Body Exploded
Taper
Combustion Chamber
Exhaust Pipe

13. Valveless

14. Petal Valve

15. Valve Grid

16. Design Matrix for valves
Ranked on a 1 to 10 scale (1 being the worst and 10 being the best)
COST
EFFICIENCY
MACHINABILITY
FUNCTIONALITY
WEIGHT
AESTETICS
TOTALS
Valve-less 10 5 4 39
Petal Valve 6 8 9 40
High Efficiency Petal Valve 42
Valve grid 2 7 31

17. Valve Design Sample Calculation.
Valve area = (0.23 x mean cross-sectional area) / 0.6 assuming the valves are going to be 60% efficient. 
Valve Area = (0.23 x 7.72)/0.6 = 2.96 in

18. Valve Design

19. Valve Component Explode
Valve Body
Diffuser
Reed Valve

20. Final Design

21. Final Design Exploded
Valve Assembly
Body Assembly

22. Building and Testing Materials Pulse-Jets Main body. Valve Body
Rolled and seem welded using 0.063” Stainless Steel Sheet Metal.
Stainless Selected because of its higher resistance to heat then mild steel.
Valve Body
CNC machined (Mill and Lathe) from Aluminum.
Aluminum used for its light weight and its machinability.
Reed Valve
0.006” Spring Steel.
 low alloy, medium carbon steel or high carbon steel with a very high yield strength. This allows objects made of spring steel to return to their original shape despite significant bending or twisting.

23. Combustion Chamber Drawing

24. Benchman Verification

31. Fuel and Fuel Delivery Fuel Fuel Delivery System Propane Propane Tank
Easily obtained.
Boiling Point below room temperature.
Being a gas allows for easier starting.
Fuel Delivery System
Propane Tank
Propane lines
Gas Fitting Nozzle
Needle Valve

32. Testing Prototype will be tested to verify thrust output.
Test Stand will be constructed to secure Pulse- Jet safely.
Digital scale will be attached to frame to calculate thrust

33. Budget Stainless steel sheet metal, with labor: $150
Valve Body: $0 on hand
Reed Valves with machining labor: $25
Propane Tank: $0, on hand
Fuel Delivery System: $0 on hand
Instrumentation: $0 on hand
Test stand material: $0 on hand
Fuel: $50
Total: $175

34. Project’s Future
Continue testing on prototype to gain further knowledge of its operating cycle.
Construct larger Jet using the knowledge gained from this smaller prototype.
Use larger engine to power to propel a manned vehicle.

35. Thank You Group 4 would like to thank Professor Roberts
Professor Rourke
Mechanology Inc. (Attleboro, MA)
Wayne’s Sheet Metal
Paul’s Custom Exhaust
Project’s Lab Staff
Machine Shop Staff

36. Bibliography
Simpson Bruce “The Enthusiasts' Guide to Pulsejet Engines”
ok/
Roy, Gabriel “Combustion processes in propulsion control, noise, and pulse detonation”

37. Questions?