A Numerical Investigation into the Effects of Fluctuating Wind on the Performance of a Small Scale Vertical Axis Wind Turbine

CFD simulations of VAWT operation in unsteady wind conditions have been conducted. Validation of the numerical model was carried out by comparison to experimental data of a wind tunnel scale rotor. The performance of the VAWT under fluctuating winds was investigated and results show a dependency to wind speed. Increasing wind speeds cause blade lift to increase more rapidly than drag resulting to higher torque values. Deviation of instantaneous rotor CP from steady wind performance curve was seen. Rotor cycle CP matches steady wind values at the corresponding mean tip speed ratio.