剪切流对潮流能水平轴水轮机水动力性能的影响

Influence of the Shear Flow on the Hydrodynamic Performance of the Horizontal Axis Tidal Current Turbine

为研究剪切流下潮流能水平轴水轮机水动力载荷的特性,基于计算流体力学(CFD)方法建立剪切流模型,计算水平轴水轮机在剪切流下的水动力载荷,并分析得出剪切流对水动力载荷的影响规律。结果表明:在剪切流情况下,水动力载荷系数时历曲线发生明显波动,除了弯矩系数的波动频率与叶轮旋转频率一致外,其他系数的波动频率均为叶轮旋转频率的2倍,且剪切流越大,水动力载荷系数的波动幅值就越大;随着速比的增大,弯矩系数的波动幅值逐渐增大,而侧向力系数波动幅值先增大再减小,在最优速比左右达到最大。研究成果可为潮流能水平轴水轮机的结构设计和性能优化提供参考。

Based on the CFD method,the hydrodynamic performance of the horizontal axis tidal current turbine under the shear flow is studied.The numerical model under the shear flow is set up,and hydrodynamic loads under shear flow are obtained,and the influence of shear rate on the hydrodynamic load is analyzed.The result shows that the time-varying curve of the hydrodynamic load coefficient under the shear flow fluctuate obviously,and the fluctuation frequency of the bending moment coefficient is the same with the rotation frequency of the turbine,but the fluctuation frequency of other coefficients is the double of that of the turbine.The fluctuation amplitude of the hydrodynamic coefficient is increasing with the shear rate,while the fluctuation amplitude of the bending moment coefficient is increasing with the speed ratio,and the fluctuation amplitude of lateral force coefficient is increasing firstly and then decrease with the speed ratio,which reach to the maximum value at the optimal speed ratio.The research result can provide reference for the structure design and performance optimization of the horizontal axis tidal current turbine.