Response of a Vertical Axis Wind Turbine to Time Varying Wind Conditions Found within the Urban Environment

Experimental testing of a vertical axis wind turbine within the urban environment was used to assess the effects that unsteady wind conditions have on the aerodynamic performance of the turbine. Temporal variation of the wind with respect to the direction and velocity fluctuations was quantified and the corresponding performance of the experimental turbine was compared to the base case wind tunnel performance. Theoretical analysis indicated that the performance of the turbine should depend on wind speed fluctuations, while remaining relatively independent of direction fluctuations. Experimental testing confirmed the independence of the direction fluctuations and quantified the impact of the wind speed fluctuations on the turbine performance. The wind speed fluctuations ( I v = based on a 10 s averaging interval) exhibited minimal impact on the performance for I v < 0.15, while for greater fluctuations the performance decreased with a roughly linear relationship with increasing I v .