【作者】 杨宇；

【导师】 骆寒冰； 李怀亮；

【作者基本信息】 天津大学 ， 船舶与海洋工程， 2018， 硕士

【摘要】 船舶在斜浪中航行时,容易发生横摇与横倾运动,这会使得船艏在发生砰击现象时带偏转角度,此时的砰击载荷比船舶在顶浪中航行时的砰击载荷更加严重。如果持续发生这种砰击现象,就会导致船艏结构发生变形,甚至会引发船艏结构的破坏,危及船舶的安全性能。因此合理预报船艏在有转角下落时的砰击载荷和结构动响应,对船舶在斜浪中航行的安全具有重要意义。基于以上现状,本文提出了CFD+FEM方法对无转角和有转角楔形体舱段结构入水砰击进行研究。本文首先提出了采用开源CFD软件OpenFOAM预报二维无转角楔形体剖面砰击载荷的方法。本文基于OpenFOAM软件中两相流求解器InterDyMFOAM开发了数值模拟二维无转角楔形体剖面入水砰击的程序包,模拟了入水砰击过程的压力和加速度时域响应过程,与入水砰击模型试验进行了对比分析,吻合很好,并对程序算法进行了敏感性分析。其次将程序算法应用于二维有转角楔形体剖面入水砰击载荷研究。然后,本文在OpenFOAM的基础上将自行开发的预报二维无转角和有转角楔形体剖面入水砰击载荷的程序算法推广到三维,将数值模拟结果与试验结果进行了对比分析,吻合很好,并讨论了三维效应。接着将二维与三维数值模拟结果进行了对比分析,并讨论了砰击压力系数。本文提出的入水砰击载荷预报方法,计算效率高,具有推广应用到预报复杂三维船首结构砰击问题的潜力。最后,本文提出了采用CFD+FEM方法对三维楔形体舱段结构入水砰击动响应过程进行数值预报。本文基于自行开发的预报三维局部结构入水砰击载荷的程序包,结合ANSYS软件能够预报无转角及有转角楔形体底部加筋板结构在入水砰击过程中的应力响应时域结果,与入水砰击模型试验结果进行了对比分析,吻合良好。本文提出的预报楔形体加筋板结构入水砰击动响应方法,为后人研究斜浪中航行船舶首部砰击动响应问题提供了可靠的依据,具有重要的理论意义和工程应用价值。更多还原

【Abstract】 When a ship is sailing in a sloping wave,roll and heel motions are likely to occur.This will cause the stern to have a deflection angle when a slamming phenomenon occurs.The slamming load at this time is greater than the slamming load when the ship is sailing in the top wolves.If such a slamming phenomenon continues,it will lead to deformation of the stern structure,and even cause damage to the stern structure,jeopardizing the safety performance of the ship.Therefore,it is reasonable to predict the slamming load and structural stress response of the ship’s stern when there is a falling angle,and it is of great significance to the safety of the ship sailing in inclined waves.Based on the conditions,this paper proposes a CFD+FEM method to study the water-entry slamming of a structure with no corners and corner wedges.This paper first proposes an open source CFD software OpenFOAM to predict the slamming load of a two-dimensional non-angled wedge profile.Based on the two-phase flow solver InterDyMFOAM in OpenFOAM software,this paper develops a package for numerical simulation of two-dimensional non-angled wedge profile water entry slamming,and it simulates the pressure and acceleration time-domain response process of water entry slamming process.A comparative analysis was performed and the agreement was very good.The sensitivity of the program algorithm was analyzed.Secondly,the program algorithm is applied to the study of the slamming load of a two-dimensional wedge-shaped profile with water entry.Then,on the basis of OpenFOAM,this paper extends the program algorithm for predicting two-dimensional wedge profiles without and with roll angle slamming loads into three-dimensions,and compares the numerical simulation results with the experimental results.And discussed the three-dimensional effect.Then compare the two-dimensional and three-dimensional numerical simulation results,and discuss the slamming pressure coefficient.The slamming load forecasting method proposed in this paper has high computational efficiency and has the potential to be applied to predict the problem of slamming in complex 3-D bow structures.Finally,this paper proposes a numerical simulation of the response process of the water-jet slamming of the three-dimensional wedge body cabin structure using the CFD+FEM method.Based on the self-developed package for predicting the slammingloads of local structures,the ANSYS software can predict stress response time domain results of wedge section with stiffened panels without and with roll angle slamming.The model test results were compared and the results were in good agreement.This paper proposes a method for predicting stress response time domain results of wedge section with stiffened panels slamming,which provides a reliable basis for future research on the response of slamming in the head of a sailing vessel in a slanting wave.It has important theoretical significance and engineering application value.更多还原