基于MPS方法,将船舱和海水简化为物理模型,并用tecpolt软件建立了船舱破损进水过程的数值模型,运用控制变量法,通过修改参数实现对舱内水高度、破口位置和大小的改变。
摘要:本文研究的是基于MPS法的舷侧破损进水的数值模拟,这个过程主要包括前期对影响舷侧破损进水过程的因素的文献收集、分析相关资料提出假设、将船舶和海水简化为理想模型、运用tecpolt软件进行几何建模、修改模型的各项参数并运行、总结分析运行结果、最终验证假设等内容。根据设计任务书对主尺度的要求,以及考虑到舱内外水面高度差、破口的位置和大小、运用控制变量法来进行方案的设计。
通过对影响舷侧破损进水过程的因素的研究,得出以下结论:舷侧破损进水由于惯性作用是一个循环往复的过程,只有当初始重力势能被水和舱壁之间的摩擦阻力做功平衡时水才会停止交换,此时舱内外水高度相同;当开口较大时,初始进流速度很大,因此需要较长的时间才能达到稳定状态;当开口较小时,初始进流速度较小,很快就可以达到稳定状态;其他因素不变时,内外水面高度差越大、破口位置越低、破口越大,初始进流速度越大。
本论文从进流速度入手,通过对多项设计方案的分析研究,找出影响破损进水的主要原因,从而对船舶能否残存、何时沉没、应采取何种应急措施和是否弃船逃生能有简单的预计和决策,对保护国家财产和人民生命安全有着重要的意义。
关键词:MPS;破损进水;进流速度;稳定状态
Abstract:This article study the flooding process of the side of the ship using MPS numerical simulation,which includes the literature on the factors influencing the process of surface damage,analyzing the relevant information to make assumptions,simplifying ship and seawater as an ideal model,using tecpolt for geometric modeling,modifying the parameters of the model and running,summarizing the results of the analysis and verifying the hypothesis finally and so on.Thinking about the difference of the height between the water inside and outside the cabin,the location and size of the break into account,according to the main scale requirements in the design assignment book and using control variable method to design the project.
It comes to a conclusion through the study of the factors influencing the flooding process of the side of the ship:the water flooding of the side of the damaged is the result of circulating due to gravity.The water can not stop exchanging until the initial gravity is compensated by the frictional resistance between the water and the bulkhead, the amount of water inside and outside the cabin is the same at this time;When the opening is large,the initial inflow rate is very large,so it takes a long time to reach a steady state;When the opening is small,the initial flow rate is small,and it is fast to achieve stability;With other factors remaining unchanged,the bigger the difference between the height of the inside and outside the water surface is,the lower the break position is,the larger the break is,he greater the initial flow rate is.
This thesis starts from the rate of inflow,finding out the main reasons of the impact of inflow through the analysis of a number of design studies,so as to have a simple idea about whether the ship can be left,when sinking,what emergency measures should be taken and whether to abandon ship to escape,it is important for protecting national property and people's lives.
Keywords: MPS;damaged inflow;rate of inflow;steady state
目录
第一章 绪论 1
1.1 研究的背景及意义 1
1.2 课题的发展与现状 2
1.2.1 关于破损进水的研究 2
1.2.2 网格法的发展现状 4
1.2.3 基于无网格法的研究 6
1.3 本文的主要工作及方法 7
第二章 移动粒子半隐式(MPS)法 8
2.1 MPS法的基本思想 8
2.2 MPS法的原理方程与模型 9
2.2.1 控制方程 9
2.2.3 梯度模型 10
2.2.3 拉普拉斯模型 10