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.

其目的是解决在持续和自由运行条件下确定滑行板未知润湿表面的问题。研究了以下三种摄动近似的情况：1）3D滑行板的高纵横比近似非线性积分方程以确定湿长度分布。该解决方案深入了解了性能的静态稳定性以及维持板暴露在静止水面上方的极限高度。所获得的润湿表面的构型很好地描绘了喷雾根线穿过硬脊的行为，但不幸的是它相当宽，与实验的一致。太宽的滑行板不能自由运行。2)引力中二维滑行板的高弗劳德数逼近以润湿长度作为长度尺度的无量纲公式将未知边界问题简化为关于弗劳德数Fn的特征值问题。特征值方程的解的两个润湿长度存在于静水面以上相同的暴露高度，然而，较短的一个可能由于失去静态稳定性而无法实现。 3) 3D 刨板的低纵横比近似找到与弓近场局部解相匹配的全局解，其中水面变形为曲率未知的抛物柱面。 Bollay积分方程表达了整个场特性，但考虑到滑行面后部产生的位移效应，求解了匹配条件。留下了一些有待解决的问题。