基于波浪能转换装置的水动力评估研究

Geometric Evaluation of Hydrodynamic Performance of Wave Energy Converter with Viscosity Correction System

流体粘度对于波浪能转换装置(Wave Energy Converter,WEC)的功率有着极大影响。通过计算流体力学(Computational Fluid Dynamics,CFD)方法,对多种点吸收式WEC模型的水动力性能进行综合研究。通过雷诺平均(Reynolds-Averaged Navier-Stokes,RANS)方程,采用非定常粘性数值方法计算粘性附加质量和阻尼,并将其引入势流理论频域模型,实现对WEC的粘性修正,同时在粘性修正的基础上改变WEC参数和取力器(Power Take Off,PTO)阻尼,分析其垂荡运动时的水动力性能。结果发现:随着高径比的增加,粘性效应对WEC的影响越来越小,且锥角系数越小,粘性对垂荡抑制效果越明显;适当增加淹没深度可以提高约29.4%的俘能幅值;加入对应波浪频率下PTO阻尼,能够提高约5.2%的俘能效率幅值,且会降低在较大频率下波浪俘获宽度的下降速率。

Fluid viscosity has a significant impact on the power of Wave Energy Converter(WEC).In this paper,the hydrodynamic performance of various point absorption WEC models is comprehensively studied by Computational Fluid Dynamics(CFD)method.By using the Reynolds-Averaged Navier-Stokes(RANS)equation and using the unsteady viscous numerical method to calculate the viscous added mass and damping,the viscous correction of WEC is achieved in the frequency domain model of potential flow theory.Based on the viscous correction,the WEC parameters and Power Take Off(PTO)damping are changed to analyze its hydrodynamic performance during heave motion.It was found that as the aspect ratio increases,the influence of viscosity on WEC decreases,and the cone angle coefficient decreases,indicating a more significant effect of viscosity on heave suppression.Increasing the submergence depth appropriately can increase the capture energy amplitude by about 29.4%.Adding PTO damping at the corresponding wave frequency can increase the amplitude of energy capture efficiency by approximately 5.2%,and reduce the rate of decrease in wave capture width at higher frequencies.