基于自适应网格的Froude-Krylov力实用计算方法  

A practical method for calculating Froude-Krylov forces based on adaptive meshes

作　　者：张腾 任俊生[1] 张秀凤[1] 白伟伟[1] ZHANG Teng;REN Junsheng;ZHANG Xiufeng;BAI Weiwei(Navigation College,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]大连海事大学航海学院

出　　处：《哈尔滨工程大学学报》2019年第10期1696-1702,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51779029)

摘　　要：为了准确地计算船舶航行中所受的Froude-Krylov力,基于四叉树划分的自适应网格对船舶瞬时湿表面进行生成,本文对低于波面且位于平均自由液面下的面元,采用解析表达式计算Froude-Krylov力,在保证计算精度的同时,其所需要的面元数量减少为计算Froude-Krylov力采用“细网格”面元数量的1/8~1/4;对与波面相交或者位于平均自由液面上的面元,采用四叉树划分对Froude-Krylov力进行精细的数值计算。利用线性理论,扰动力采用三维时域格林法在船体平均湿表面上进行计算。结果表明:将WigleyⅠ型船的计算结果与试验值及其他方法结果进行充分对比,证明本文方法预报船舶在波浪中运动的有效性。To accurately calculate the Froude-Krylov(F-K)forces acting on ships at sea,adaptive meshes,based on quad-tree subdivision,were adopted to generate the exact instantaneous wetted surface of the ship.For the panels that were both under the instantaneous wave profile and the mean free surface,F-K forces were evaluated by exact analytical pressure integration expressions.These can ensure accuracy while reducing the number of panels to 1/8~1/4 of fine-mesh;for panels interacting with an instantaneous incident wave profile or above the mean free surface,the numerical method,using quad-tree subdivision,was used to precisely compute the F-K forces.Using the linear theory,the disturbing force was calculated on the mean wetted hull surface by the three-dimensional time-domain Green function method.Results showed that the calculated results for the WigleyIhull,compared with experimental data and other published results,proved valid and of great importance for the prediction of ship motions at sea.

关 键 词：Froude-Krylov力 适应网格 瞬时湿表面 面元 四叉树划分 线性理论 解析表达式 三维时域格林函数 

分 类 号：U661.32[交通运输工程—船舶及航道工程]