基于二维变形体入水的滑行艇水动力研究

摘要

In order to find an accurate and convenient method to evaluate the hydrodynamic forces of planing craft,the body lifts of the planing craft in the steady sailing situation was researched based on the VOF model including air and water built up with the CFD method under the simplified model of the 2.5D theory.To validate the accuracy,the 2D wedge bodies entering water were calculated first and the lifts parameters were compared with the approximate theory.The three dimension hull sailing in the calm water was transformed into a deforming section entering water.The deforming section entering water was simulated with dynamic mesh technique.By integrating the lifts in different time of the section along the ship longitude,the dynamic lift of the hull was obtained.Meanwhile,the numerical simulation of three dimension planing craft sailing in calm water was calculated and the results of lifts at different speeds were compared with the two dimension results and experiment data.The results show that the 2D and 3D results both match the experiment data.It is feasible to use the numerical method with CFD technique to calculate the hydrodynamic of planing craft in high speed based on two dimension deforming body entering water.%为寻找准确便捷估算滑行艇水动力的方法,在二维半理论的简化模型下,通过CFD方法建立气液二相流VOF模型,数值模拟二维变形体入水砰击过程,对滑行艇稳定直航状态下的动升力进行研究.为验证数值模型精度,首先对二维楔形体入水进行数值模拟,并将得到的砰击参数与理论近似解结果进行比较,进而根据船模实验中的航行姿态,将三维船体稳定直航简化为二维变形横剖面入水过程并通过动网格技术进行数值模拟.将变形横剖面入水不同时刻的动升力沿船长方向对应的横剖面位置进行积分得到全艇的动升力.同时,对三维船体进行绕流计算,将得到的动升力与二维积分结果以及实验值进行对比.计算结果表明,二维和三维计算结果均与实验数据基本吻合,通过CFD方法计算基于二维变形体入水的高速滑行艇水动力问题具有可行性.