水沙环境对海流能机组水动性能的影响

Effect of water-sediment environment on hydrodynamic performance of a tidal current turbine

为了探究水沙环境下海流能机组的水动特性,首先采用CFD-DPM模型仿真沙粒对120 kW海流能叶片翼型升阻力系数的影响,再基于叶素动量理论(BEM,blade element momentum)计算水沙环境下120 kW海流能机组的捕获功率,最后从叶片设计的角度出发,提出了为能充分利用沙粒对海流能机组功率的促进作用以及尽量减小沙粒对海流能机组功率的削弱的方法。研究结果表明:当颗粒直径为20μm时,随着沙粒质量浓度的增加,沙粒能够促使海流能机组功率提升,当颗粒直径为2 500μm时,海流能机组功率因沙粒的存在而被削弱;随着翼型攻角增大,翼型升力系数增大,颗粒对翼型升阻力系数的影响程度增强,升阻力系数的变化量增加;小升力系数的翼型可以充分利用小直径颗粒对机组的功率提升,也可以降低大直径颗粒造成的机组功率削弱。

In order to explore the hydrodynamic characteristics of a tidal current turbine under a watersediment environment,the CFD-DPM model is employed to study the effect of sand particles on the airfoil lift and drag coefficients of 120 kW tidal current turbine blade.Based on the blade element momentum theory(BEM),the 120 kW tidal current turbine power is calculated.From the perspective of blade design,the method to make full use of or reduce the influence of sand particles on the power of the tidal current turbine is put forward.The results show that when the particle diameter is 20μm,as the concentration of sand grains increases,the sand particle can improve the tidal current turbine power.When the particle diameter is 2 500 μm,the particle will reduce the power.As the angle of attack increases,the lift coefficient increases,and the effect of the sand particle on the lift and drag coefficients is enhanced.Airfoils with a small lift coefficient would receive power improvement with small particles or power loss reduction with large particle diameters.