Nonlinear-Free Surface Effects: Experiments and Theory
Nonlinear-Free Surface Effects: Experiments and Theory
复制标题
DOI：
--
复制
发表时间：
1983-09
期刊：
影响因子：
--
通讯作者：
M. Greenhow;Woei-Min Lin
中科院分区：
文献类型：
--
作者：
M. Greenhow;Woei-Min Lin
摘要：本报告的目的是介绍一些简单的二维实验的结果，在这些实验中，水面从其未受干扰的位置移动了很多，线性理论很可能会出错。特别注意的是支付的自由表面和一个移动的身体，汇合的边界条件的交点可能会导致奇异的自由表面位移和速度，如线性理论预测。这些奇异性似乎是避免在真实的流体形成的射流，在实验的规模，迅速打破成喷雾的作用下的表面张力。然而，众所周知，势理论足以描述射流的形成，因此，正在寻求在交叉点周围有效并基于势理论的一些局部模型，以便稍后匹配到适当的远场条件。这样的远场或外解可以用现有的程序计算，并且希望当由内解补充时，它们将提供许多极端波或极端运动问题的合理完整的描述，例如，翻船和撞击。在大多数情况下，实验是在高速下进行的：这意味着在局部区域忽略重力是近似正确的，这对理论产生了相当大的简化。
Abstract : The object of this report is to present the results of some simple two-dimensional experiments in which the surface of the water is displaced a good deal from its undisturbed position, and for which linear theory is likely to be in error. Particular attention is paid to the point of intersection of the free surface and a moving body, where the confluence of boundary conditions can cause singularities in the free surface displacements and velocities, as predicted by linear theory. These singularities appear to be avoided in the real fluid by the formation of jets, which at the scale of the experiments, quickly break up into spray under the action of surface tension. Nevertheless it is known that potential theory is adequate to describe the formation of jets and therefore some local model, valid around the intersection point and based on potential theory, is being sought for later matching to appropriate far field conditions. Such far field or outer solutions may be calculated with existing programs, and it is hoped that when complemented by an inner solution, they will provide a reasonably complete description of many extreme wave or extreme motion problems e.g., ship capsize and slamming. For the most part the experiments have been performed at high speed: this means that it is approximately correct to ignore gravity in the local region and this effects a considerable simplification to the theory.