风力机叶片的气固两相边界层特性数值模拟研究

STUDY ON CHARACTERISTICS OF GAS-SOLID TWO-PHASE BOUNDARY LAYER OF WIND TURBINE BLADES

鉴于西北地区沙尘天气频繁,大部分风电机组不可避免会在风沙环境下运行,该文以直径0.5 m的小型两叶片风力机为研究对象,利用数值计算,对该风力机叶片三维边界层特性进行气固两相模拟探究,分析其在气固两相环境下的边界层厚度分布规律以及边界层内流体切向速度的分布规律。取沙粒直径为100μm,沙粒浓度为8.3×106μg/m3,与洁净空气下的叶片边界层特性进行对比,发现风力机叶片尾缘及叶根部分吸力面边界层受到气固两相环境的影响较明显,加入固相沙粒会阻碍边界层内流体的速度剪切特性,使流体倒流和正向恢复的能力有所减弱。这对于翼型边界层的分离控制及提高风沙环境下风力机的气动特性有一定指导意义。

As sandstorm weather occurs frequently in northwest China,most wind turbines are inevitable often to run in the sand and dust environment. A small two blades wind turbine with diameter of 0.5 m is researched by numrical simulation in this paper to explore the influence of gas-solid two-phase conditions on the characteristics of boundary layer of wind turbine blades. The thickness distribution and fluid tangential velocity distribution law in the boundary layer under gas-solid two-phase environmental condition is analyzed. The sand particle diameter is 100 μm,and the sand concentration is 8.3 × 106μg/m3. By comparing with the results under clean air condition,it is found that the influence of the gas solid two phase environment on wind turbine blade suction surface boundary layer is mainly on the root and trailing edge of blade. Adding solid sand hinders the velocity shear characteristics of fluid in the boundary layer,the ability of fluid flowing reverse and recovering forward is weakened. This condusion may has some guiding significance for controlling the flow separation of airfoil boundary layer and improving the aerodynamic characteristics of wind turbine in the wind and sand environment.