基于重叠网格法的结构物入水砰击研究

Numerical Simulation of Water Entry of Structures Based on Overlapping Grid Method

采用重叠网格法,对楔形体的入水砰击问题进行模拟。将数值计算结果与试验数据比较,验证了该数值方法的有效性;在此基础之上,探究斜升角、初始速度和下落高度对楔形体入水砰击的影响。初始速度和高度对楔形体入水过程中初次砰击压力峰值的影响很大。随着入水深度的增加,气体逸出,出现二次峰值;当斜升角大于等于30°时,最大砰击压力出现在楔形体底端附近。此外,速度对二次砰击峰值的影响要比斜升角的影响大。

Slamming phenomenon of water entry of structures exists widely in the field of naval architecture and ocean engineering.In this paper overlapping grid method is applied to simulate water entry,with the time variation of slamming pressure as well as motion characteristics of a wedge-shaped structure focused on.A numerical example was selected to verify the effectiveness of the present method by comparing with experimental results.Effects of the dead rise angle,initial falling speed and falling height on the water entry were studied.It is shown that initial falling speed and initial height have great influence on the first peak of the impact pressure,and when the structure submerges deeply,the gas escapes and then the secondary peak appears.when the deadrise angle is over 30 degrees,the maximum stress point is near the bottom of the body.In addition,compared to the deadrise angle,the initial falling speed has a more apparent influence on the pressure peak of the second slamming.