水下平板与波浪相互作用完全非线性数值模拟(英文)

利用完全非线性数值波浪水槽技术研究水下平板与波浪的相互作用。假定水下平板厚度极薄、刚性,位于有限水深并且非常接近自由水面。应用四阶龙格库塔方法追踪每一时刻的波面形状,采用阻尼层来吸收反射波以保证算法的稳定性,同时引入平滑和重组的方法抑制自由表面控制点的较高梯度。通过对波浪与浮动圆柱相互作用的数值模拟证实了数值波浪水槽方法的有效性,计算结果与线性理论吻合良好。在波浪数值水槽方法中引入造波板模拟波浪产生并与水下平板发生相互作用,应用傅立叶解析方法对波面变形、波浪力作了分析。结果表明在板非常接近自由水面的情况下会表现出现很强的非线性,揭示了线性理论的局限性。

Fully nonlinear hydrodynamic simulation of submerged horizontal plate

A fully nonlinear numerical wave tank technique is utilized to simulate a submerged horizontal plate. The plate is supposed to be thin, rigid and very close to free surface of water at finite depth. At each time step the wave profile is traced by fourth order Runge-Kutta method and damping zone is used to absorb outgoing wave and let simulation perform long time. Smoothing and regridding method is adopted to remove high gradients of control nodes on free surface. Numerical validities of wave tank technique are compared with linear theory of wave elevation and hydrodynamic wave interaction with a half floating cylinder, and the results show excellent agreements. Time domain wave plate simulation is carried out under the wave generated by wave maker. The free surface deformation, wave exciting force and Fourier analysis of wave plate interaction are carried out in time domain. It is found that for plate very close to free surface, strong nonlinearity occurs, which reveals the limitation of linear theory.