对转式垂直轴风力机气动性能研究

Aerodynamic Performance of Counter-Rotating Vertical Axis Wind Turbine

为了改进漂浮独立式垂直轴风力机的气动和稳定性能,提出风力机的新型结构设计理念,即同轴对转式垂直轴风力机.基于计算流体力学理论,借助雷诺时均剪切应力传输RANS SST k-ω湍流模型对风力机进行数值模拟,并结合涡流理论,比较对转式与独立式垂直轴风力机在不同叶尖速比(TSR)时的气动和稳定性能.结果表明,相同流场条件下,对转式风力机浮式平台的稳定性更强.当TSR<1.3时,长时间的失速状态使得对转式风力机的脱涡现象更严重,风能利用效率更低;当TSR>1.3时,外流场的风能更多地被对转式风力机转子吸收,风力机的远端涡流长度更短且脱涡强度更低,风能利用效率更高.同轴对转式的结构设计理念和分析方法对海上垂直轴风力机的性能优化有一定的参考价值.

In order to improve the aerodynamic performance and stability of the floating platform of an isolated vertical axis wind turbine,a novel structure design concept of the wind turbine with a coaxial counter-rotating vertical axis was proposed.Based on the computational fluid dynamics theory,a numerical simulation was conducted with the application of the Reynolds-averaged Navier-Stokes(RANS)shear stress transfer(SST)k-ωturbulence model,and combined with the eddy current theory,the aerodynamic performance and stability with different tip speed ratios(TSR)were further compared.The results show that in the same flow field,the floating platform of the counter-rotating wind turbine is more stable.When TSR<1.3,the long-time stall makes the de-vortex of the counter-rotating wind turbine more serious,and the wind energy utilization efficiency is lower.When TSR>1.3,the wind energy in outflow field is more absorbed by the rotor of the counter-rotating wind turbine.In addition,the length of remote vortex is shorter and the intensity is lower.Therefore,the wind energy utilization efficiency is higher.Coaxial counter-rotating has a certain reference value for the performance optimization of the vertical axis wind turbine.