Thread by @ParveenKaswan

Today #India successfully flight tested Hypersonic Technology Demonstrator Vehicle (HSTDV).

India will soon be the fourth country to have hypersonic missiles. After US, Russia & China only.

Congratulations to all scientists. 1/n

Hypersonic missiles fly with more than 5 Mach speed. Which means five times speed of sound. Supersonic is more than Mach 1.

They use SCRAMJET engines. Higher version of RAMJET engines, in short Supersonic Combustion RAMJET (SC+RAMJET) engines. 2/n

Ramjet engine works on principle of Ram effect. Which in simple terms utilising vehicular speed for compression.

But for combustion speed need to be slowed down. Combustion at Sub sonic speed. Which means during expansion there is a check on velocity of vehicle. 3/n

But SCRAMJET uses technology which can do combustion in supersonic speed also. Hence after expansion, vehicular velocity will be higher. Which is Hypersonic in nature.

This is a great deal. All explained in simple terms. Benifits of being aerospace engineer.

To further simplify the terms used. An air breathing engine (e.g. jet engine) works in four stages.

Intake- when air gets in

compression- when air is compressed. In RAMJET air is compressed by its vehicular speed

combustion- burning fuel

expansion- thrust production stage

Hypersonic vehicles*. As tested today. There could be hyper sonic missiles without scramject also. With some other technology. I am just talking about Missiles with SCRAMJET.