双水翼耦合振荡捕获潮流能系统2维数值模拟

中文摘要: 提出了一种双水翼耦合振荡捕获潮流能的系统，该系统在河床及浅海具有良好的适应性。建立了相应系统的数学模型及网格模型，将域动网格策略用在滑移交界面内部流体域，利用Fluent求解绕2维双振荡翼流动的数值模型。研究了折算频率、俯仰振幅及雷诺数对NACA0015型双水翼水动力特性及捕获潮流能性能的影响，以及在不同运动参数下水翼的升阻力、俯仰力矩、功率系数的变化规律。结果表明，振荡水翼的折算频率、俯仰振幅和雷诺数会影响水翼边界层的分离及周围漩涡的产生和脱落，继而影响振荡翼的升阻力特性和俯仰力矩特性。折算频率与俯仰振幅对振荡水翼系统的捕能效果有较大影响。当水翼的振荡频率为0.28、俯仰振幅为75°、雷诺数为5×10 5时双水翼耦合振荡捕获潮流能系统的水动力和捕能性能较好，捕能效率可达40%。
Abstract:A new concept of hydrokinetic turbine using dual oscillating hydrofoils to extract energy from water currents(tidal or gravitational) was presented,which is particularly well suited for riverbeds and shallow waters near the coasts due to its rectangular extraction plane.The corresponding mathematical model and mesh model were established.A domain dynamic mesh strategy was used on fluid domain within sliding interface to make it move with the airfoil.The software Fluent was used to solve the turbulent flow around the airfoil.The influence of the reduced frequency,pitching amplitude and Reynolds number on the NACA0015 oscillating airfoil in aerodynamic characteristics and energy extraction performance was studied in the paper.Results showed that the reduced frequency,pitching amplitude and Reynolds number could influence boundary layer separation and vortex structure around the hydrofoils,affecting lift characteristics,drag characteristics,pitching characteristics and energy extraction performance.Reduced frequency and pitching amplitude had a greater influence on the time averaged power coefficient and energy extraction performance.With the reduced frequency of 0.14,pitching amplitude of 75° and Reynolds number of 5×10 5, the hydrodynamic and energy extraction performance could be better.The efficiency of energy extraction could reach 40%.