Numerical Investigation of Power Output and Flow Visualization of Straight blade Vertical Axis Wind Turbine Integrated with Wind Accelerator

Abstract

The main goal of wind turbine development is to increase the power output of the turbine. One of the methods for promising of wind power output is to increase the effective wind velocity by using an augmentation device around the rotor. This paper is an attempt to observe the effect of flat plate acceleration device on the performance of the wind turbine. A numerical simulation was conducted to investigate the performance of straight bladed vertical axis wind turbine applying simple flat plate wind acceleration device. In this study, straight bladed vertical axis wind turbines (SVAWT) of NACA0016 with wind cord length 113 mm was used to investigate its performance by adding two flat plates on both sides of the rotor at different separation gaps. The power output of the turbine at various wind speed of 2.6-7.5 m/s at different separation gaps and different clearance between turbine and accelerator were investigated. Wind turbine power output has significantly increased by presenting two flat plates around the rotor. Maximum peak power has attained at certain separation gap from the view of the upwind side and it was 1.5 times of the bare turbine output. The flow phenomenon behind the blade was also investigated. The flat plate guides the mainstream to be a narrow passage between the two flat plates, creating a vortex behind the flat plate which phenomenon cannot occur in the bare turbine case. Narrow passage mainstream between flat plates gives more accelerated effect of the blade, resulting speed increasing of upstream side blade to make lift. There are sensitive changes of power output when the positions of both plates are changed to different separation gaps and different clearances from their reference places. All the results demonstrate that the flat plate technique can give high increased power to the straight bladed vertical axis wind turbine.