大粗糙度弦向分布对风力机气动性能影响

INFLUENCE OF CHORDAL DISTRIBUTION OF LARGE ROUGHNESS ON AERODYNAMIC PERFORMANCE OF WIND TURBINE

针对5 mm大尺度蚊虫尸体在叶片上的附积问题,采用带转捩的k-ωSST湍流模型,以NERL Phase VI风力机为研究对象,从不同弦向覆盖位置入手,对大粗糙度下风力机气动性能进行数值模拟。研究结果表明,粗糙度对风力机整体做功具有较大影响,粗糙度越大效率降低越显著;粗糙度使在叶片靠近叶尖位置的吸力面促成小型低压涡,转捩提前;该效应在大尺度粗糙条件下表现明显,附着涡强度也更大;在叶片压力面添加75%c粗糙度会使翼型产生的气动损失最大。

The accumulation of 5 mm large-scale mosquito corpses on the wind blade affects the overall aerodynamic performance of wind turbine.In order to investigate this problem,the aerodynamic performance of wind blade covered with different scales roughness in chord-wise was simulated by using SST k-ωturbulence model.The numerical research was carried out on the NERL Phase VI wind turbine.The results show that the roughness greatly impacts on the performance of the wind turbine,i.e.increasing roughness results in the significant efficiency decrease.In addition,the roughness attribute to a small low pressure vortex in the negative pressure surface of region near the blade tip,and also advance the transition.This effect is more obvious under the condition of the larger scale roughness,and the intensity of the wake vortex will be greater.Adding roughness at 75%c on the pressure surface of the blade will generate the greatest pneumatic loss to the airfoil.