楔形体入波浪水面数值模拟

数值模拟分析楔形体入波浪水面流体力学现象和运动姿态变化历程，为水上飞机在波浪水面起降提供技术和理论支持。基于有限体积法求解非定常雷诺平均Navier-Stokes（URANS）方程和SST k-ω湍流模型，结合整体动网格法的速度入口造波方法、阻尼消波法和流体体积（VOF）液面捕捉技术构造数值波浪水池，耦合三/六自由度模型，实现楔形体入线性规则波和不规则波的数值模拟。在楔形体入静水面算例验证的基础上，详细研究二维楔形体在线性规则波波峰、波谷、平衡位置-上行速度和下行速度处入水过程的受力特性和运动姿态变化。结果表明：速度入口造波方法的波浪数值解与理论解析解较吻合，偏差为1%；在二维楔形体入规则波过程中，楔形体所受垂向力和垂向速度变化趋势相同，对横向位移影响较小，其数值变化少于0.01；在平衡位置入水过程中，模型的滚转角和横向速度变化明显，其数值变化约为波峰、波谷位置处的8倍和10倍。分析原因：平衡位置处波浪内流速度变化较快，模型所受波浪力冲量较大，且楔形体两侧斜边与波浪的相互作用力也参与到模型的运动中。数值模拟二维楔形体在线性不规则波5个随机时间点入水及三维楔形体在波峰、平衡位置-上行速度处入水过程，其变化规律及形成原因与入规则波相似。

Numerical simulation of wedge impacting on wavy water

The characteristics of force and change histories of motion during wedge impacting on wavy water are examined and simulated numerically in order to provide technical and theoretical support for seaplane ditching on wave. Solutions are generated with the finite-volume method based on Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations and the SST k-ω turbulence model. A velocity-inlet boundary wave maker and a momentum absorbing zone combination with Volume of Fluid (VOF) model are employed to generate waves. The global moving mesh method and the methods above coupled with three/six degree of freedom model adapts to simulate the free falling wedge on linear regular and irregular waves. The characteristics of force and the changes of motion during two-dimensional (2D) wedge entering on wave at crest, trough, balance positions (up-speed and down-speed) are studied particularly based on the validation of numerical examples. The results show that the numerical wave simulation results show good agreement with analytical wave with a deviation of 1%. In the case of 2D wedge impacting on regular wave, the vertical velocity and force have the same trend at different positions of regular wave. There is a little effect on displacement in the x-direction and its value changes less than 0.01. The roll angle and lateral velocity of the wedge change significantly at the balance positions of the linear regular wave, the values are eight and ten times at the crest and trough respectively. This is due to the faster change of velocity and hydrodynamic at balance positions of wave than crest and trough. Another interesting reason is the different relative force of the oblique sides of wedge and wave, which participated in the process of wedge impacting on wave and effected its change. Furthermore, several numerical cases of 2D wedge impacting on irregular wave at five random time points and three-dimensional(3D) wedge entering on regular wave at crest and balance position(up-speed) are presented and investigated, the changes and causes of them are similar to 2D wedge impacting on regular wave at different positions.