圆柱体入水砰击载荷的模型试验和数值预报比较研究

发布时间：2018-05-27 17:14

本文选题：入水砰击 + 圆柱体　；参考：《天津大学》2014年硕士论文

【摘要】：舰船在恶劣海况下高速航行,当船首出水再次入水时候,首部结构容易遭受剧烈的水动力砰击载荷作用。根据发生砰击的船首部位不同,可以分为船底砰击和外飘砰击。严重的砰击会对局部结构安全性造成威胁,同时砰击还会引起船体梁的振动,威胁整体结构安全性。研究舰船砰击问题具有非常重要的理论意义和工程价值。本论文主要针对局部砰击问题进行研究。由于船舶首部三维形状的复杂性,合理预报其砰击载荷难度较大。论文对船舶首部砰击问题做了简化,针对典型的圆柱体结构开展入水分析,采用试验和刚性体数值模拟方法研究其载荷变化。论文研究采用粘性流体力学软件Fluent开展刚体入水砰击载荷数值工作,针对30度楔形体和圆柱体入水砰击两个问题,开展了数值模拟工作,预报结果与公开文献发表的实验数据进行了对比,吻合较好,验证了数值模拟方法的合理性和准确性。论文针对圆柱体入水砰击问题,开展了模型试验研究,焊接制作了铝制圆柱体结构,设计实施了一套入水砰击模型试验机构,测试了入水砰击的加速度、结构应力和压力响应。然后,采用基于Fluent软件的CFD数值方法,开展了入水砰击载荷数值分析工作,预报的刚体入水加速度和砰击压力载荷与模型试验结果吻合较好。本论文提出的CFD数值模拟方法,具有较好的应用前景,可以应用到更加复杂的二维和三维刚体结构入水砰击载荷问题,可以为今后研究具体船首局部结构砰击载荷问题提供技术支持。
[Abstract]:When the ship is sailing at high speed under the bad sea conditions, the head structure is vulnerable to severe hydrodynamic slamming load when the bow outlet is re-entered into the water. According to the bow of the ship slamming, it can be divided into bottom slamming and floating slamming. Severe slamming will threaten the safety of local structures, and will also cause vibration of the hull girder, threatening the safety of the whole structure. It is of great theoretical significance and engineering value to study the ship slamming problem. This paper focuses on the local slamming problem. Due to the complexity of the 3D shape of the ship's head, it is difficult to predict the slamming load reasonably. In this paper, the first slamming problem of a ship is simplified, and the load variation of typical cylindrical structure is studied by means of test and rigid body numerical simulation. In this paper, the viscous fluid dynamics software Fluent is used to carry out the numerical work of rigid body slamming load, and the numerical simulation work is carried out to solve the problem of 30 degree wedge and cylinder entering water slamming. The prediction results are in good agreement with the experimental data published in the public literature, and the rationality and accuracy of the numerical simulation method are verified. Aiming at the problem of water slamming in cylinder, the model test is carried out, the aluminum cylinder structure is made by welding, a set of water slamming model test mechanism is designed and implemented, and the acceleration, structural stress and pressure response of water slamming are tested. Then, the numerical analysis of water slamming load is carried out by using CFD numerical method based on Fluent software. The predicted acceleration and slamming pressure of rigid body are in good agreement with the model test results. The CFD numerical simulation method proposed in this paper has a good application prospect and can be applied to the more complex two-dimensional and three-dimensional rigid body structure water slamming load problem. It can provide technical support for future research on slamming load problem of specific bow local structure.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U661.4

【参考文献】