Scramjet Engine

In News

  • Recently, The Indian Space Research Organisation (ISRO) has successfully conducted the Hot Test of Scramjet Engine.

What is a Scramjet Engine?

  • A scramjet (supersonic-combustion ramjet) is a ramjet engine in which the airflow through the engine remains supersonic, or greater than the speed of sound. 
  • A scramjet has no shock cone and slows the airflow using shockwaves produced by its ignition source in place of a shock cone. 
    • This allows the scramjet to operate efficiently at extremely high speeds.
  • Scramjet powered vehicles are envisioned to operate at speeds up to at least Mach 15. 

Difference Between Ramjet and Scramjet

  • A scramjet is a ramjet with supersonic combustion. In ordinary ramjets, the air is decelerated to subsonic velocities before combustion, but this is not the case in a scramjet.
  • Ramjets have a velocity range of 1 to 6 Mach in theory, but Scramjets have a range of 12 to 24 Mach in theory.
  • Ramjets and scramjets can’t produce thrust at zero velocity, they need a lot of airflow to start.
  • Scramjets have a higher specific impulse than Ramjet.
  • Owing to subsonic combustion, Ramjet has greater efficiency and operability than Scramjet, which has a lesser efficiency due to supersonic combustion.

Source: TH