1. PRESENTED BY
KVK

2. PRINCIPLE OF RAMJET ENGINE
THE FUNCTION OF A SUPERSONIC AND
SUBSONIC DIFFUSER IS TO CONVERT THE
KINETIC ENERGY OF THE ENTERING AIR INTO A
PRESSURE RISE CALLED RAM PRESSURE.

3. RAMJET BASIC OPERATION
Ramjet has no moving parts
Achieves compression of intake air by forward speed of vehicle
Fuel
injectors

4. RAMJET BASIC OPERATION
Air entering the intake of a supersonic aircraft is slowed by
aerodynamic diffusion created by the inlet and diffuser to low velocities.
Expansion of hot gases after fuel injection and combustion accelerates
exhaust air to a velocity higher than that at inlet and creates positive
thrust

5. HyFly RAMJET CONCEPT
Hypersonic Flight Demonstration Program
Cruise Flight Mach Number ~ 6
Range 600 nm (1111 km)

6. HyFly RAMJET CONCEPT
HyFly program was initiated in 2002 by DARPA (Defense
Advanced Research Projects Agency) and U.S. Navy's ONR
(Office of Naval Research)
 to develop and test a demonstrator for a hypersonic Mach 6+
ramjet-powered cruise missile
Prime contractor for HyFly missile is Boeing, Aero jet builds
sustainer engine
Air-launched from F-15E and accelerated to ramjet ignition speed
by solid-propellant rocket booster

7. •Engine runs on conventional liquid hydrocarbon fuel (JP-10)
•Much easier to handle than cryogenic fuels (LH2) used on other hypersonic
scramjet vehicles
• Sustainer engine of HyFly is a dual-combustion ramjet (DCR) (very complex)
•Two different air inlet systems
•Operate as a "conventional" ramjet with subsonic combustion
•Operate at hypersonic speeds as a scramjet
•First scramjet engine (hybrid or otherwise) to demonstrate operability
with LH2 fuel

8. Hercules MK 70 rocket booster

11. SUMMARY
 Ramjet develops no static thrust
 Relies on ‘ram’ compression of air
 Requires high speed flight
 Performance depends on increase in stagnation temperature across burner
(combustor)
 Efficiencies (thermal, propulsive, and overall) increase with increasing flight
Mach number
 Next step: We desire an engine that develops static thrust
 Put in a device to mechanically compress air (compressor)
 Put in a device to power compressor (turbine)
 Solution: Turbojet engine

12. ADVANTAGES
LOW FRONTAL AREA.
CO-EFFICIENT DRAG IS LOW.
HIGH PRESSURE AND TEMPERATURE CAN BE
EMPLOYED.
LOAD CAPACITY IS VERY HIGH.

13. DISADVANTAGES
THERE WE HAVING ALTITUDE LIMITATION.
LOW THERMAL EFFICIENCY.
HIGH TSFC.
EROSION OCCURS AT THE NOZZLE DUE HIGH
TEMPERATURE OF GAS COMING OUT FROM THE
NOZZLE.