项目名称: 表面波中结构入水的三维全非线性砰击问题研究
项目编号: No.11302057
项目类型: 青年科学基金项目
立项/批准年度: 2014
项目学科: 数理科学和化学
项目作者: 孙士丽
作者单位: 哈尔滨工程大学
项目金额: 28万元
中文摘要: 很多水面结构在波浪中航行或者作业时,结构的一部分或者整体在波浪力的作用下会产生出入水运动。当入水运动发生时,结构不可避免的与流体产生很猛烈的,甚至具有强烈破坏性的砰击,如滑行艇或气垫船底板的入水砰击,高速船船艏的入水砰击,恶劣海况下某些海洋平台与水面的砰击,水上飞机在波浪环境下降落而产生的砰击等。鉴于此,本课题着重研究轴对称体以及非轴对称体在表面波中以各种方式入水包括垂直入水、斜入水、匀速入水和变速入水时的三维砰击问题。本项目拟推导并建立入水物体和表面波相互作用的三维全非线性数学模型, 采用高阶边界元法对控制方程进行离散,采用改进的欧拉法结合自由液面变形特征对其位置及速度势进行更新,辅以网格重构技术、光顺技术、拓展坐标系、辅助函数方法等,分析物体在表面波中入水时的三维压力分布特征、三维卷曲自由液面的变形特征、合外力等物理量,进而探讨结构在表面波中入水的危险受力状态。
中文关键词: 波浪;砰击;入水;非线性;边界元法
英文摘要: When the surface structures navigate or operate in the wave, part of the body or the whole body will move into or out of water due to the wave force. When a body enters water in surface waves, it will inevitably crash the fluid and the force between them is rather huge which may be destructive,such as the impact from the planning hull or the air-cushion vessel, from the bow of the high speed ship,from the platform in violent wave or from a falling water plane. As a result, water entry of axisymmetric or non-axisymmetric bodies in surface waves is emphasizely analyzed in this program in various manners such as vertical water entry, oblique water entry, constant speed entry and oblique speed entry. The three dimensional (3D) fully nonllinear numerical model of the interaction between the body in water entry and surface waves is deduced and erected, in which the higher order boundary element method is used to discretize the governing equation, the free surface is updated by a modified Eulerian method under the consideration of the charicteristics of the free surface transformation, the remeshing and smoothing are used every few time steps and the streched coordinate system and the auxillary function are adopted. Based on the numerical procedures discribed above, the 3D distribution of the pressure on the body surfa
英文关键词: Wave;Impact;Water entry;Nonlinear;Boundary element method