Performance Evaluation of Small-Scale Vertical Axis Wind Turbine by Optimized Best Position Blade Pitching at Different Tip Speed Ratios

Abstract

This paper analyzes and evaluates the effect of various design and operating parameters in the view of their influence on the starting turbine by itself, power coefficient and overall performance of the vertical axis wind turbine. Best pitch position of each blade in the rotation of turbine at different azimuth angles has been calculated at different tip speed ratios (TSRs) by using the aerodynamic analysis. Best pitch position of the blade is fixed at specific azimuth angle to produce the maximum tangential force in order to start turbine by itself and improve the power coefficient of the turbine. The double-multiple streamtube model is used for the present analysis. The results indicate that the best pitch position blade method improves the self-starting capacity and power coefficient. The best position blade pitching curve-1 with 45° pitch angle gives maximum power coefficient for TSRs of 1.0, and the best position blade pitching curve-5 with 15° pitch angle gives maximum coefficient of power about 0.53 for TSRs at 2.3. The results indicate that the optimized blade pitching with pitch variations from 45° to 10° improves performance of the turbine for TSRs 0 < λ < 3.