Wind Tunnels were not in fashion until recently. Suddenly they are not only in fashion for engineering colleges offering Aerospace degrees, there are competitors trying to manufacture wind tunnels with competitive costs.
Sunshine Measurements have been manufacturing wind tunnels for the past 45 years. Premier research institutions such as NAL, IISc, along with young educational colleges such as IITs Bombay, Gauhati, Kharagpur, Madras etc. have commissioned and continue to use tunnels made by Sunshine. We have made wind and water tunnel, as well as subsonic and supersonic tunnels for our customers.
While, competitive cost structures are always causing us to evolve our own manufacturing process to find efficiencies and reduce costs, one basic element dominates the creation of wind tunnels of any size – the motor and fan drive along with its controller.
The motor and fan assembly specification is driven by the wind speed requirement of the tunnel. By way of example, a subsonic wind tunnel with 600mm x 600 mm test cross section with a speed of 50 m/s demands a power rating of 25KW. Such motors are manufactured by leading makers for a cost of approximatley Rs 5 Lakhs.
Another tunnel specification we have built is a cross section of 1.5m x 1.5 m running at wind speeds of 90m/s. This tunnel required a motor of rating 700 – 800 KW. Such a drive including motor, fan and controller is sold by leading motor makers for Rs. 60 – 80 Lakhs.
The cost for this key element in a wind tunnel typically constitues from 1/3 to 1/2 of the total cost of sale and installation of the wind tunnel.
Competitive pricing lower than such numbers are indicative of the use of ineffective motors where the design wind speed cannot be physically achieved.
In our experience, we have been engaged to repair or replace such tunnels at several institutions as the previous vendor provided a non working tunnel.
We urge our potential customers to understand this key fact and choose their tunnel specifications and acceptance testing criteria appropriately.
