VAWT is tested in the subsonic wind tunnel, whose test section size is 600*600*4000 mm. Maximum speed that can be attained in the test section is 45 m/sec with a bell mouthed entry having two stainless steel mesh of sizes 8 and 16 respectively. At the bottom of the tunnel there is a circular opening through which the base of the VWAT is fixed with the help of screws and nuts using bottom support I and II, whereas airfoil shaped wind blades, rotor supporting frames were fixed into the test section by opening top and side chambers, shown in Fig. 2. (c). Once the VAWT is placed in the test section, wind tunnel is operated at different speeds. Wind speed is calculated by considering the manometers height difference using the following equation based on the Bernoulli’s principle.
V^2= (Manometer fluid density)/ (Air density)*2*g*(h2-h1)