Defence Minister Rajnath Singh recently inaugurated the advanced Hypersonic Wind Tunnel (HWT) test during his visit to Defence Research and Development Organisation’s (DRDO’s) Dr APJ Abdul Kalam Missile Complex in Hyderabad. India has become the third country after Russia and US to have such a facility.

About Mega Hypersonic Wind Tunnel Facility?

It is the state-of-the-art Hypersonic Wind Tunnel Test facility which is a pressure vacuum-driven enclosed free jet facility having a nozzle exit diameter of 1 meter. 

It can simulate Mach No 5 to 12

India is the third country after the USA and Russia to have such a large facility in terms of size and operating capability.

It is an indigenous development built in partnership with Indian industries.

As per the press release by Defence Services, the facility is provided with the capability to "simulate hypersonic flow over a wide spectrum and will play a major role in the realization of highly complex futuristic aerospace and defence systems.”

Significance

This indigenously-developed facility has the capability to simulate hypersonic airflow and will prove crucial in India's quest to develop futuristic aerospace and defence technologies. 

It is a great effort on part of DRDO thus giving a boost to Make in India.

How Does A Wind Tunnel Work?

Wind Tunnels are large tubes with air passing at high speed through them. 

These tunnels direct air around an object which makes it reach the flying stage. 

What Is Hypersonic Wind Flow?

The Hypersonic flow is when the speeds are much higher than the speed of the sound that is 330 m/s. 

It can be achieved at Mach 5 or greater. 

The Hypersonic test facility includes shock layer, viscous interaction layer, entropy layer and stagnation temperature of the flow.

Differences On The Basis of Mach Number

Mach number is less than 0.8- subsonic

Mach number is between 0.8 and 1.2- Transonic

Mach number is 1- Speed of the sound

Mach number of between 1.2 and 5.0-Supersonic sounds

Mach number is between 5 and 10- Hypersonic sounds

Mach number is greater than 8.8- Hypervelocity

It may not be a weapon, but the successful test of Hypersonic Wind Flow Tunnel is a significant milestone in the nation's quest to develop hypersonic and long-range cruise missiles. It is a response to China’s DF-17 which is a developing hypersonic cruise missile. Hypersonic is the future in defence and India is leading the race now.