全非线性自由面边界条件求解船舶兴波问题

A solution to wave making problem using fully nonlinear free-surface boundary condition

采用Wyatt公式迭代满足非线性自由面边界条件求解船舶非线性兴波问题,自由面物理量导数采用坐标平面变换方法计算,远前方无波条件通过Raven优化得到的4点向前差分格式结合配置点前移来满足,且将面元上置以消除自由面诱导速度计算的奇异性,提高迭代的收敛性和稳定性.通过对Wigley船型和Series60船型兴波阻力及波形计算,计算结果与线性Dawson方法及试验结果比较,验证了本方法的稳定性和精度,且对非线性兴波阻力计算过程中的程序编制、网格配置、阻力计算等诸多环节进行了探讨和分析.

Wyatt＇s expressions were used to solve the fully nonlinear wave making problem. The derivatives of the velocity potential were calculated with the coordinate transformation method. Both Raven＇s optimized four-point upward difference scheme and collocation-point shift method were used to satisfy the radiation condition. Desingularization is achieved by raising the panel a distance above the collocation-poipt, The computations were carried out for two different ship models： Wigley hull and Series 60 hull. The wave profile and wave making resistance were calculated and compared with both of the linear Dawson method result and the experimental data, which valid present method. The coding method, mesh setting, and resistance calculation method were discussed.