The Effect of Wind Direction and Distance Between Axes on Two Rotating Straight Wing Vertical Axis Wind Turbines

Abstract

Numerical simulation has been carried out for two-dimensional flow around two straight wing vertical axis wind turbines (SW-VAWT) with two blades. We divide the flow region into two parts so that two wind turbines can rotate independently in the simulation. Each part consists of two sub-regions; one sub-region rotates together with the wind turbine and the other is fixed in the external space. Every region has slender “overlapped area” and we use the overset grid system there. The Reynolds number is fixed to 2000 and a turbulence model is not used. In this study, the ratio of radius of the turbine to the distance is 1 to 2.8 and 1 to 3.2, and the flow is assumed to come parallel and perpendicular to two turbines. By changing the wind direction and the distance between turbines to analyze the interaction, we can estimate changes of torque coefficient and those of flow field quantitatively.