不同直径颗粒在S809翼型流场中的运动特性及对其气动性能的影响

MOTION CHARACTERISTICS OF DIFFERENT DIAMETER PARTICLES IN FLOW FIELD OF S809 AIRFOIL AND EFFECT ON ITS AERODYNAMIC PERFORMANCE

以风力机专用翼型S809为研究对象，采用SSTk-ω湍流模型和离散相模型（DPM）进行数值计算，研究不同直径颗粒在流场中的运动特性及其对翼型气动性能的影响。结果表明，颗粒入射轨道较少（颗粒浓度低）时，不能采取等效，应保证轨道数精确。而轨道数足够多时，可用较小的轨道数等效；随着颗粒直径增大，颗粒的跟随性变差，绕过前缘后远离吸力面的情况加剧。进入边界层和分离涡的颗粒及其所能达到的最大速度均减小，且最大速度点沿流向移动；当直径增大到50μm时，出现颗粒碰撞壁面的现象，且直径越大碰撞现象越剧烈；各直径颗粒对8．2°和12．2°攻角的升力系数影响很小，而对于18．1°攻角，0．5μm的颗粒会明显增大其升力系数。

Taking the wind turbine-specific airfoil $809 as the research object, the SST k-ω turbulence model and the discrete phase model （DPM） are used for numerical calculation to study the motion characteristics of different diameter particles in the flow field and the influence of particle diameter on the aerodynamic performance of the airfoil. The results show that when the particle incidence trajectory is small （low particle concentration）, the equivalent cannot be taken, the number of trajectory should be accurate ; when the number of trajectory is sufficient, the smaller number of trajectory can be adopted. With the increase of particle diameter, the follow ability of the particles deteriorates, and the situation away from the suction side intensifies after the particles bypass the leading edge. Both the particles entering the boundary layer and separating vortex and the maximum speed reached by particles are reduced, and the maximum speed point moves along the flow direction ; When the diameter is increased to 50 μm, the phenomenon that particles collide with the wall occurs, and the larger the diameter, the more severe the collision phenomenon; Each diameter particle has little effect on the lift coefficient of the 8.2° and 12.2° angle of attack, while for the 18.1° angle of attack, the 0.5μm particle will significantly increase its lift coefficient.