垂直轴5叶片阻力型风力机的数值分析

摘要

文章采用滑移网格技术对垂直轴5叶片阻力型风力机的瞬态流场进行了数值模拟计算，首先通过对计算区域出口边界上风速的数值分析，得到了恰当的计算区域大小；分析了风车输出功率随风车所处位置的变化规律，确定了风车在计算区域中的合理位置，以及此时风车的风能利用率；并进一步通过改变叶片宽度，得到了优化的叶片宽度及相应的风能利用率。结果显示，对于风轮半径为2 m、叶片宽度为0．76 m的5叶片风力机风车，在风速为6 m/s时，当风力机转速为12 r/min其功率达到最大，且风能利用率为19．3％；对于相同风轮半径的风车，优化的叶片宽度为0．8 m，并且在风速为8 m/s时，其风能利用率在转速为17 r/min状态下达到最大值24．3％。%The numerical simulation on the transient flow field of 5-blade vertical axis resistance type wind turbine (VAWT)was performed by using sliding meshes.The suitable numerical model for computing the wind-power utilization coefficient was obtained by comparing the mesh size effect firstly;the proper region size for the computation was determined by comparing the outlet wind speed with respect to the infinitely distant one;and the appropriate position for the turbine was determined by comparing the position effect on the wind-power utilization coefficient rationally.Furthermore,the optimized width of blades was attained to improve the wind power utilization coefficient.The results show that the maximum power utilization coefficient is 19.3%at wind speed 6 m/s and the rotation rate 12 r/min for the turbine′s radius 2 m and the width of blades 0.76 m;the wind power utilization coefficient can reach to 24.3% at the wind speed 8 m/s and the rotation rate 17 r/min for the optimized width of blades 0.8 m.