Session: 09-01-07 Wind Turbine Aerodynamics - 2

Paper Number: 79515

79515 - "A Study of Offshore Wind Turbine Wake Effects in Yaw Conditions Using an Improved Actuator Line Method" 

The study of wind turbine wakes is very important for the layout of offshore wind farms. In large offshore wind farms, the wake from upstream wind turbines leads to lower velocity and stronger turbulence intensity of downstream wind turbines, which reduces the power and lifespan of downstream wind turbines. In recent years, the method of reducing the influence on the downstream by changing the wake by setting the yaw angle of the wind turbine has received constant attention. In this paper, a numerical method based on OpenFOAM solver combined with an improved actuator line method (ALM) is applied to study the wake interactions between yaw wind turbine and downstream wind turbine. The ALM is mainly improved in two aspects to improve the calculation accuracy. Gaussian anisotropic body force projection was introduced to make the force closer to the real condition of the blade. For freestream velocity sampling, the integral velocity sampling method is introduced to reduce the influence of bound vortex. Numerical accuracy is validated with a benchmark wind turbine model (NREL 5MW wind turbine). And then the wake effects from upstream turbine in yaw conditions are assessed in detail, which has good agreements with the published results in the literatures using full rotor model (FRM) and SOWFA. The results of this paper prove that the proper yaw angle can improve the total power of wind farm, and also prove that the improved ALM can get more accurate results with lower computational cost.

Keywords: Wind turbine wakes, yaw, OpenFOAM, actuator line method, NREL 5MW

Presenting Author: Ning Fan Harbin Engineering University

Authors:

Ning Fan Harbin Engineering University
Kangping Liao Harbin Engineering University
Qian Wang Harbin Engineering University