Effect of yaw angle on the global performances of Horizontal Axis Wind Turbine - QBlade simulation

Abstract

The yaw angle has a great importance in the wind turbine working. Even though most of the large turbines have yaw mechanisms, they do not have an instant response. The aerodynamic forces and torque on the blades fluctuate, depending on the yaw angle. The design and the numerical simulation of the wind turbine were performed with the Blade Element Momentum method in open source QBlade software. The power coefficient, torque, thrust and power output generated by wind turbine in non-yawed flow were analysed. The simulations have been performed for non-yawed flow, in rotational speed range between 2100 and 3300 rpm and wind velocity of 15 m/s. Simulations for yaw angle range have been performed between ± 60°, with 5° step at rated rotational speed of 2700 rpm. The results are presented through charts for global parameters in both non-yawed flow, and yawed flow. The effect of yaw angle on global performances of the wind turbines is more important after the value of 25° when the power output decrease with about 15% from power output in non-yawed flow. The average value of the exponent from conventional relation of power coefficient in yawed flow is 1.77 in good concordance with experimental tests.