New Delhi: The Indian Space Research Organization (ISRO) recently conducted the maiden blow-down test of their all-new wind tunnel, installed at the Vikram Sarabhai Space Centre. It said that this tunnel is a system to aid the aerodynamic design of rockets and re-entry spacecraft by characterising a scaled model by evaluating forces, moments, load distribution, unsteady pressures, acoustic levels etc.

The most reliable method to test a rocket or an aerospace vehicle is by launching or flying it. However, if one is to design an all-new aerospace vehicle and intends to validate the newly-developed prototype, the preliminary step would be to test it in a wind tunnel. A large tube with air flowing through it can be used to replicate the interaction between the air and an object flying through the air, such is the working principle of a wind tunnel.

Known as the Trisonic Wind tunnel, it facilitates testing under three conditions – subsonic (below the speed of the sound), at the speed of sound and supersonic (faster than the speed of sound). The tunnel measures 160 metres in length and has a maximum cross-section of 5.4 metres. The tunnel can simulate flight conditions from 0.2 times the speed of sound (68 m/s) to 4 times the speed of sound (1360 m/s).

The wind tunnel moves air around an object, making it seem as if the object is flying. However, the object is held in a stationary and steady manner. The object could be a sub-component, a scale model of the aerospace vehicle or a full-sized vehicle. As the tunnel is in operation, special equipment can be used to study the various forces that are acting upon the test object.

It is known that the Indian space agency is working on a manned spaceflight programme, on a test vehicle(RLV-TD) that can be launched like a rocket and land like a plane and also various heavy-lift rockets for future use. Every new concept and design being developed by the Indian space agency can now be validated at the new wind tunnel and thereby fine-tune it further.