Syllabus section: science and technology

 

Why in news?

Defence Research and Development Organisation's (DRDO) state-of-the-art Hypersonic Wind Tunnel (HWT) test facility placing India in a select group of nations with the technology.According to reports, only the United States and Russia have similar facilities.

Wind tunel:

• Wind tunnels are large tubes with air blowing through them.

• The tunnels are used to replicate the actions of an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft will fly.

• NASA uses wind tunnels to test scale models of aircraft and spacecraft. Some wind tunnels are large enough to contain full-size versions of vehicles.

• The wind tunnel moves air around an object, making it seem as if the object is really flying.

What is Hypersonic Wind Tunnel Test Facility?

• The Hypersonic flow is a flow where the speeds are much higher than the local speed of sound. The hypersonic flow is generally defined as the flow at Mach 5 or greater.

• The Hypersonic test facility should simulate the flow features of this regime, that is, of flow rate Mach 5 or greater.

• It includes shock layer, viscous interaction layer, entropy layer and stagnation temperature of the flow.

• The recently inaugurated Hypersonic Wind Tunnel Test Facility will simulate hypersonic flow over a wide spectrum.

• It will play a major role in realizing highly complex futuristic aerospace and defence system.

• It is a high-pressure vacuum driven enclosed jet facility that has a Nozzle Exit Diameter of one metre.

• It will simulate Mach 5 to Mach 12. Mach is the multiplication factor to the speed of sound. It is called Mach Number.

• Mach number of the ratio between flow velocity past a boundary to the local speed of the sound. Mach 5 says that the speed is 5 times the speed of sound.

 

Source: The Hindu