Performance Improvement by Control of Wingtip Vortices for Vertical Axis Type Wind Turbine

Abstract

The present paper describes control of wingtip vortices generated by vertical type wind turbine. The wind turbine consists of three circular cylinders. Each cylinder rotates on its own vertical axis and moves in orbit. It is known that wingtip vortices give rise to decrease of power generation performance as well as aerodynamic noise. Therefore, the goal of the study is to control wingtip vortices and to improve power generation performance. Numerical study was conducted for 14 models to find out control factors to suppress wingtip vortices. Numerical simulation visualized wingtips by streamlines as well as pressure distribution on the circular cylinder for evaluating Magnus effect. As a result, the following findings were obtained: 1) Installation of fully covered protection plates at both ends of the circular cylinder blades is greatly effective to suppress the wingtip vortices. 2) Curved wings attached to each cylinder are more effective to enhance power generation efficiency than flat ones, due to great increase in Magnus effect caused by large pressure difference on both sides of the curved wing. The power efficiency of the optimized model was improved up to 2.8%, which means 11 times that of the original model.