Investigation of Effective Parameters on Gorlov Vertical Axis Wind Turbine

Abstract

In this paper, we aim to develop a low-cost model for evaluating the aerodynamic design and performance of Gorlov vertical axis wind turbine (VAWT). To this end, a double multiple stream tube (DMST) model, which is based on the blade element momentum theory (BEM) has been developed for Gorlov VAWTs. The developed model is validated by comparing the obtained results with the available results in the literature; in addition, overall evaluation on the effects of geometrical and operational parameters, including profile of the blade airfoil, number of blades, helical angle, chord length, aspect ratio and free wind velocity have been performed for aerodynamic performance and the torque coefficient curves of Gorlov VAWT. Considering the results of parametrical evaluation on Gorlov turbine, maximum power coefficient ($${{C}_{P}}$$) is 0.479 for the tip speed ratio ($$\lambda $$) of 3.5 in NACA 0018 airfoil. In addition, it becomes evident that the number of blades and helical angle are important parameters in reducing the aerodynamic loads and improving the rotor stability. As the blade chord length or aspect ratio increases, the performance improves at low $$\lambda $$ values; however, it decrease at high $$\lambda $$ values and peak $${{C}_{P}}$$. Moreover, self-starting behavior has been improved with increasing the blade chord length or free wind velocity and deteriorated by the usage of thinner airfoils. For the studied Gorlov turbine, the performance curves become wider until free wind velocity reaches to the rated velocity, which is 12 m/s for the studied Gorlov turbine.