Blade Optimization of a Small Vertical-Axis Wind Turbine Using the Response Surface Method: Fid-Bau Portal

Blade Optimization of a Small Vertical-Axis Wind Turbine Using the Response Surface Method

Kim, Chul-Kyu / Ali, Sajid / Lee, Sang-Moon / Jang, Choon-Man

Abstract The hybrid renewable energy system considered in the present study mainly consists of wind turbines, solar panels, a small hydro turbine, and an energy storage system (ESS). The integration of various renewable energy sources complements the discontinuities between the energy sources, thus producing a stable energy supply. Recently, small wind turbines having vertical axes are attracting attention because of low cut-in speeds, low noise output, low cost, and high flexibility. In the present study, the blade optimization of a 1.5 kW vertical-axis wind turbine has been performed in order to improve the turbine performance used in a hybrid renewable energy system. Two design variables, which are used to define the shape of the turbine blade, are introduced in order to increase the turbine power performance. The power coefficient is selected as an objective function for the present optimal design of the turbine blades. The Response Surface Method (RSM) combined with three-dimensional Navier-Stokes equations is introduced to find out the optimum shape of the turbine blades. To analyze the three-dimensional flow field of the wind turbine, the general analysis code, SC/Tetra, is employed. An SST turbulence model is applied to estimate the eddy viscosity. Throughout the shape optimization of the turbine blade, the power coefficient of the turbine is increased by decreasing the local losses around the blade. It is found that the optimum point of the design variables corresponds to the maximum thickness location of 24% and the chord length of 210 mm on the response surface. Consequently, the performance of the wind turbine using the optimized blade improved the power coefficient of 12.7% compared to that of the reference model.