Air-Breathing Scramjet Engine

Subject: Science and Technology

The Indian Space Research Organisation’s (ISRO) successfully conducted the hot test of scramjet engine.
In an air-breathing scramjet engine, air from the atmosphere is rammed into the engine’s combustion chamber at a supersonic speed of more than Mach two.

ScramJet Engine

A scramjet is a supersonic-combustion ramjet engine in which the airflow through the engine remains supersonic (greater than the speed of sound).
Scramjet-powered vehicles can operate at speeds up to Mach 15.
Scramjet engines facilitate supersonic combustion by breathing oxygen from the atmosphere during flight.
It then allows the oxygen to mix with hydrogen already stored in the vehicle, triggering combustion, and producing the required thrust to lift the satellite to its designated orbit.
Such engines that can breathe oxygen from the atmosphere play a significant role in space technologies as they help reduce the need for propellants by about 70%.
Benefits:
- Mastering the air-breathing scramjet technology will lead to the development of hypersonic missiles, faster civilian air transportation and facilities for putting satellites into orbit at a low cost.

Ramjet Engine

A ramjet engine operates by the combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as compared to normal jet engines where the compressor section compresses the air.
The airflow through a ramjet engine is at a subsonic speed (less than the speed of sound).
Ramjet engines can operate from Mach 3 to Mach 6.
Mach number is the ratio of the speed of an aircraft (vehicle) to the speed of sound.