1. Ramjets By
Robert Espey

2. What is a Ramjet?
A ramjet is a jet engine that relies on forward momentum to create pressure instead of a moving piston or fan
Requires forward motion to produce thrust
Uses continuous combustion

3. How Does it Work? Incoming air is slowed to subsonic by cone
Slowed air creates pressure needed for combustion
Fuel injected into pressurized air
Flame ignites mixture
Air expands and flows through nozzle
Exhaust generates forward thrust
Must be at least Mach1 before operating

4. How Does it Work? (Cont.)
The thrust produced is based on pressure differentials at different sides of the plane
Limited by excessive temperatures and pressures at higher speeds and low pressure differentials at low speeds

5. Schematic of a Scramjet (air remains supersonic)
Advantages
No moving parts
Higher efficiencies
Speeds limited only by temperatures and pressures engine can handle
Schematic of a Ramjet
VS.
Schematic of a Scramjet (air remains supersonic)

6. Disadvantages Low Fuel Efficiency Only operates at speeds above Mach1
Caused by low compression ratios
High speed creates drag
Only operates at speeds above Mach1

7. Uses
Ramjets and Scramjets have been used in missiles, helicopters, and the SR71 Blackbird with varying degrees of success.

8. Applications
The United States funded a nuclear scramjet project for missiles called ‘Project Pluto”
Realized that ICBM’s did the job better and that low flying radioactive reactors weren’t the best idea

9. Works Cited
“Ramjet Engines.” 3 Dec < “The Ramjet/Scramjet Engine.” 2 Dec < “Here Comes the Flying Stovepipe.” Time Magazine. 3 Dec < “Ramjet.” Wikipedia. 2 Dec <