【作者】 常城；

【导师】 马山；

【作者基本信息】 哈尔滨工程大学 ， 力学， 2019， 硕士

【摘要】 运用CFD技术研究船舶耐波性问题,相对于势流方法更加耗时,但可以直观地观察船舶在水中的瞬时位置、局部流场的流体瞬时压力分布以及船舶任意部分在任意方向的受力时间历程等。当对船型作微小优化或安装附体时,基于粘流理论的CFD模拟可帮助研究人员更方便、直观地捕捉流场细节。本文借助CFD软件STAR-CCM+,对一艘14000TEU集装箱模进行模拟,并通过与势流方法以及试验值进行对比,以验证CFD分析方法的准确性。本文给出了波浪水池的构建方法、计算船舶绕射力、静水阻力、波浪增阻过程中的湍流模型选择及网格划分方法,并给出了模拟结果与势流方法计算结果及试验值的对比与分析。本文主要内容如下:依据船模的波浪水池试验的工况,借助CFD软件STAR-CCM+,文中依据船模大小及波浪参数,建立了数值波浪水池,并设置了不同的波长和波高。给出模拟适合船模波浪水池试验的CFD数值水池的构建方法,包括水池尺度的确定、网格划分、湍流模型的选择以及造波、消波方法。为验证波浪水池对船舶粘流水动力分析的适用性,首先模拟了约束船模的绕射水动力问题。在数值波浪水池的基础上,加入约束船模,分别监测了无航速、有航速情况下,不同波长、波高下的垂荡、纵摇方向的力和力矩,并给出了不同网格数量时的绕射力曲线;同时根据二维势流切片法和三维泰勒展开边界元法(TEBEM)程序,计算出了这两个方向的力和力矩,验证了 CFD方法的可靠性。然后进行了顶浪入射波中船舶波浪增阻的模拟分析。主要讨论了船模在不同航速、波长、波高的来波中的波浪增阻问题,并给出了船舶垂向运动RAO比较。文中详细阐述了研究过程中网格划分方式、网格数量等因素对计算结果的影响。此外,拖曳水池试验的结果亦在文中给出,验证了本文阐述的CFD模拟方法的可靠性。更多还原

【Abstract】 Compared with potential flow method,CFD technology is more time-consuming to study the wave added resistance of ships.However,the instantaneous position of the ship in water,the instantaneous pressure distribution of the fluid in the local flow field and the time history of any part of the ship in any direction can be visually observed.CFD simulation based on viscous flow theory can help researchers to capture flow field details more conveniently and intuitively when the ship type is slightly optimized or the hull is installed.In this paper,the procedures and the results of CFD simulation of the 14000TEU containership are illustrated via STAR-CCM+.The accuracy of the CFD results are verified by comparing the results in potential theory and the experimental data.This paper illustrates the general method of the construction of the virtual wave tank,the comparison of the results in various turbulence models and the mesh generating methods,the process of computing diffraction forces,the resistance in calm water and wave added resistance,as well as the results both in simulation and in using strip theory.And the experimental results are given as a material for the simulating ones to verify their accuracy.The main contents of this paper are given as follows:Based on the working conditions of the model test,the process of establishment of the virtual wave tank is illustrated with the aid of the application STAR-CCM+,with the reference of the parameters of the ship model and waves of different length and height.Strategies of determination of the size of the virtual tank,meshing,turbulence models and methods of wave making and absorbing are also demonstrated.Before studying the problems of wave added resistance,in order to verify the validity of the virtual tank on the analysis of the ship CFD,simulations of diffraction forces on the fixed ship model are processed.The model of simulation is based on the established virtual tank and the virtual fixed ship model.Vertical forces and moments under different forward speed,wave lengths and wave heights are monitored,and the curves of the diffraction forces of various meshing models are also given.Meanwhile,according to the strip theory method and Taylor expansion boundary element method(TEBEM),the computing results of the forces and moments in vertical motions are also given,which verify the validity of the CFD method.The simulation of wave added resistance is carried out,which considered different forward speeds,wave length and wave heights.Not only the time histories of wave added resistance are illustrated,but also the RAOs of heave and pitch motions.Results of different meshing methods and quantities are demonstrated and studied,.Furthermore,the results of model test are also given in this paper,which verify the validity of the CFD method in studying the problems of wave added resistance.更多还原