Note4Students

From UPSC perspective, the following things are important :

Prelims level: Trisonic Wind Tunnel

Mains level: Not Much

The new trisonic wind tunnel at the Vikram Sarabhai Space Centre (VSSC) was inaugurated by conducting the first blow-down test successfully.

What is a Wind Tunnel?

Wind tunnels are large tubes with air moving inside.
The tunnels are used to copy the actions of an object in flight.
Researchers use wind tunnels to learn more about how an aircraft will fly.
Space agencies uses wind tunnels to test scale models of aircraft and spacecraft. Some wind tunnels are big enough to hold full-size versions of vehicles.
The wind tunnel moves air around an object, making it seem like the object is really flying.

How do Wind Tunnels work?

Most of the time, powerful fans move air through the tube.
The object to be tested is fastened in the tunnel so that it will not move.
The object can be a small model of a vehicle. It can be just a piece of a vehicle.
It can be a full-size aircraft or spacecraft. It can even be a common object like a tennis ball.
Smoke or dye can be placed in the air and can be seen as it moves. Threads can be attached to the object to show how the air is moving.
Special instruments are often used to measure the force of the air on the object.

‘Trisonic’ refers to the tunnel’s capability to test in three speed regimes—below the speed of sound (subsonic), at the speed of sound (transonic), and above the speed of sound (supersonic).
Its parts include air storage vessels, a settling chamber where the airflow is ‘smoothened’ out, and nozzles for releasing the air into the test section.
It is about 160 metres long and measures 5.4 metres at its widest part.
In a ‘blow down test’, stored gases are released and blown through the tunnel’s test section, simulating flight conditions.
The tunnel can simulate flight conditions from 0.2 times the speed of sound (68 metres per second) to four times the speed of sound (1,360 metres per second), according to the space agency.
Commissioned in 2017, this tunnel can simulate flow speeds up to Mach 12.