Ramjet

PRESENTED BY

KVK

PRINCIPLE OF RAMJET ENGINETHE FUNCTION OF A SUPERSONIC AND

SUBSONIC DIFFUSER IS TO CONVERT THE KINETIC ENERGY OF THE ENTERING AIR INTO A PRESSURE RISE CALLED RAM PRESSURE.

RAMJET BASIC OPERATION

Ramjet has no moving partsAchieves compression of intake air by forward speed of

vehicle

Fuelinjectors

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

HyFly RAMJET CONCEPT

Hypersonic Flight Demonstration Program Cruise Flight Mach Number ~ 6Range 600 nm (1111 km)

HyFly RAMJET CONCEPTHyFly 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

•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

Hercules MK 70 rocket booster

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

ADVANTAGESLOW FRONTAL AREA.CO-EFFICIENT DRAG IS LOW.HIGH PRESSURE AND TEMPERATURE CAN

BE EMPLOYED.LOAD CAPACITY IS VERY HIGH.

DISADVANTAGESTHERE WE HAVING ALTITUDE

LIMITATION.LOW THERMAL EFFICIENCY.HIGH TSFC.EROSION OCCURS AT THE NOZZLE DUE

HIGH TEMPERATURE OF GAS COMING OUT FROM THE NOZZLE.