竖轴潮流能水轮机横荡和艏摇耦合水动力分析

Hydrodynamic analysis of vertical-axis tidal turbines under the coupled motion of sway and yaw

为了分析竖轴潮流能水轮机在无界均匀流下横荡与艏摇耦合运动时的水动力特性,本文采用滑移网格和动网格技术研究了轮机恒定转速下横荡和艏摇同频耦合运动及不同频耦合运动对水轮机水动力载荷的影响规律。研究结果表明:当水轮机发生横荡和艏摇同频耦合运动时,水动力载荷瞬时值明显产生比横荡(或艏摇)运动更大的波动,载荷时变频率与耦合运动频率相同,其幅值随耦合运动频率的增加而增加;当横荡频率比艏摇频率大较多时,水动力载荷的变化规律和横荡运动时的基本一致,但随着艏摇频率的逐渐增加,艏摇运动的影响就会体现出来。研究结果可为漂浮式载体的运动响应研究、水轮机更多自由度运动水动力分析及电能控制等提供相关数据。

This study aims to explore the effect of coupled sway and yaw frequency on the hydrodynamic characteristics of vertical-axis tidal turbines that work at a constant rotation speed.Sliding and moving mesh technologies are adopted to analyze hydrodynamic load in unbounded uniform flow regions under similar and different frequency coupling motions,respectively.Results show that the instantaneous value of hydrodynamic load produces greater fluctuations compared with the sway(or yaw)motion when the hydraulic turbine sway and yaw are coupled at the same frequency.When the load time-varying frequency is the same as the coupled motion frequency,the fluctuation amplitude increases with the increase in the coupled motion frequency.When the sway frequency is much larger than the yawing frequency,the variation rule of hydrodynamic load is basically consistent with the yawing motion.However,as the yawing frequency gradually increases,the influence of yawing motion is reflected.The results of this study can provide relevant data for the following:research on the motion response of floating carriers,hydrodynamic analysis of the turbine with more degrees of freedom,and electric energy control.