二维矩形舱晃荡现象的实验与数值对比研究

发布时间：2018-03-13 16:14

本文选题：二维矩形舱　切入点：横摇　出处：《大连理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：液体载运设备或内部有液舱结构的载运设备逐步走向大型化,尤其是随着天然气等气体能源的广泛应用,大型低温液体载运设备的需求量增大。在船舶与海洋工程领域内,液化天然气船(LNG, Liquid Natural Gas)和浮式液化天然气船(FLNG, Floating Liquid Natural Gas)是两大代表性的用于装载低温液体的载运设备。船体所在特殊环境决定了其会受到外界风、浪、流的作用产生六个自由度的响应,进而引起船体内部低温液舱内的低温液体的晃荡。晃荡荷载会影响液舱结构安全、船体运动姿态以及船体稳性,是决定LNG和FLNG安全性的关键因素。因此分析液舱晃荡现象,评估晃荡荷载并在LNG和FLNG的设计过程中降低晃荡荷载是当今船舶与海洋工程领域内一个比较重要的问题。为了能够对复杂液舱在复杂激励或真实激励下的晃荡荷载研究提供依据并提高研究结果的可信度,本文利用模型试验和数值模拟两种晃荡荷载常用研究方法在相同的条件下对简化模型——二维矩形液舱在船体常见响应类型——横摇的简谐激励下的晃荡荷载进行对比研究。从机理上分析对比两种方法得到的晃荡荷载的一些基本特性。通过分析对比两种方法的结果的一致性来验证两种方法的可信度,总结两种方法的结果之间的差别以及产生出入的原因,提出提高两种研究晃荡荷载的方法的改进措施。结合两种方法的结果总结得到二维矩形舱内液体在横摇激励下的晃荡荷载的空间分布、受横摇激励频率和幅值的影响以及受载液水平的影响规律。为今后的复杂液舱晃荡荷载的研究打下基础。并将结果应用在液舱设计乃至LNG和FLNG的整体设计上。
[Abstract]:Liquid carrying equipment or carrying equipment with internal tank structure is gradually moving towards large scale, especially with the wide application of gas energy such as natural gas, the demand of large cryogenic liquid carrying equipment is increasing. In the field of ship and ocean engineering, LNG (Liquid Natural Gas) and floating LNG (Floating Liquid Natural Gas) are two typical carrier equipment for loading cryogenic liquids. The special conditions of the ship's hull make it subject to external wind and waves. The effect of the flow produces a response of six degrees of freedom, and then causes the sloshing of the cryogenic liquid in the cryogenic tank inside the hull. The sloshing load will affect the structural safety of the tank, the motion attitude of the hull and the stability of the hull. Is the key factor to determine the safety of LNG and FLNG. Evaluating the sloshing load and reducing the sloshing load in the design process of LNG and FLNG is an important problem in the field of ship and ocean engineering nowadays. To provide the basis for and increase the credibility of the results of the study, In this paper, two common research methods of sloshing load, model test and numerical simulation, are used to study the sloshing load of simplified model-two-dimensional rectangular tank under the simple harmonic excitation of the common response type of ship hull under the same conditions. Comparative study. Some basic characteristics of the sloshing load obtained by the two methods are analyzed and compared in mechanism. The reliability of the two methods is verified by analyzing the consistency of the results of the two methods. Summarizing the differences between the results of the two methods and the reasons for the discrepancies, Two improved methods to study sloshing load are put forward, and the spatial distribution of sloshing load of liquid in two-dimensional rectangular tank under rolling excitation is summarized by combining the results of the two methods. Under the influence of rolling excitation frequency and amplitude, as well as the influence law of loaded liquid level, this paper lays a foundation for the future study of complex tank sloshing load, and applies the results to the tank design and even to the overall design of LNG and FLNG.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U661.7;U674.133.3

【参考文献】