STUDY OF COANDA EFFECT APPLIED TO VERTICAL WIND TURBINE BLADES

摘要

This article presents study of Coanda effect on a patented vertical wind turbine design performance. The study involves both theoretical study and numerical simulation. The numerical modelling and the flow analysis were done using Computational Fluid Dynamics (CFD) simulation techniques in a virtual wind tunnel. The goal is to find the wind pressure distribution profile behind the blades that is further used to optimize the shape of the blade and the angle of the auxiliary blade that introduces the Coanda effect. The Coanda effect is introduced by providing an auxiliary short blade attached to the tip of the turbine blade that redirects the wind flow behind the blade. Because the protuberant shape of the surface behind the blade, incomplete expansion of flow takes place. This creates a low pressure behind the blade, and results with a pull force, dragging the blade in the rotation direction. In other words, the shape of the blade creates a low pressure using the Coanda effect that results in enhancing lifting force effect producing more electricity at the same wind speed. The experimental results are used to verify the simulation results.