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Pertubational study on the flow field around a planing plate with splay phenomena

具有张开现象的滑行板周围流场的摄动研究

基本信息

批准号：
06651077
负责人：
MATSUMURA Kiyoshige
金额：
$ 1.47万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06651077/
关键词：
planing ship wetted surface unknown boundary problem eigenvalue problem spray phenomena aspect ratio unstablity perturbation method 不安定浸水長浸水面積

项目摘要

It is intended to solve a problem to determine the unknown wetted surface of planing plates in sustained and free-running conditions.Three cases of the pertubational approximation are studied as followings :1) High aspect ratio approximation of 3D planing plateA non-linear integral equation to determine the wetted length distribution is derived. The solution gains as insight into static stability in performance and the limit height to sustain the plate in exposure above the still water surface. The obtained configuration of wetted surface draws well the behavior of the spray root line crossing the hard chine, however it is unfortunately rather wide to coincide with the experimental one. Too wide planing plate can not freely run.2) High Froude number approximation of 2D planing plate in gravitationNon-dimensional formulation by using the wetted length as a length scale reduce the unknown boundary problem to an eigenvalue problem with respect to Froude number Fn. Two wetted lengths of the solution of the eigenvalue equation exist to the same rise in exposure above the still water surface, however, the shorter one may be unrealizable because of losing static stability.3) Low aspect ratio approximation of 3D planing plateIt is intended to find a global solution matching with the local solution in the bow near field where the water surface deformed as a parabolic cylinder with unknown curvature. Bollay's integral equation expressing the whole field characteristics but the matching condition is solved for taking account of the displacement effect generating by the aft part of planing surface. Some problems to be solved are left.

为了解决滑行板在持续和自由滑行条件下的未知湿表面的确定问题，本文研究了三种情况下的摄动近似：1）三维滑行板的大展弦比近似导出了确定湿长度分布的非线性积分方程。该解决方案的收益作为洞察静态稳定性的性能和极限高度，以维持板暴露在静水表面以上。所得的湿表面形状较好地描述了喷雾根部线穿过硬脊的特性，但遗憾的是，它与实验结果吻合得太宽。太宽的滑行板不能自由滑行。2）二维滑行板在重力作用下的高弗劳德数近似以浸润长度为尺度的无因次列式将未知边界问题转化为关于弗劳德数Fn的特征值问题。在静止水面以上，存在两个相同的浸润长度，其中较短的一个可能因失去静稳定性而无法实现。3）三维滑行板的低展弦比近似在船首近场，水面变形为曲率未知的抛物柱面，寻求与局部解相匹配的全局解。为考虑滑行面后部产生的位移效应，求解了反映整个场特性的Bollay积分方程，但需满足匹配条件。留下了一些有待解决的问题。