基于CFD的岸壁效应的数值模拟

发布时间：2018-04-05 17:23

本文选题：CFD　切入点：岸壁效应　出处：《大连海事大学》2016年硕士论文

【摘要】：随着船舶尺度的逐渐增大,很多航道、港内附近水域等变得相对狭小,成为受限水域。船舶在这些水域所受到的水动力和水动力矩也发生了显著变化,很多专家学者曾对此做了大量的研究。本文在前人研究的基础上,考虑流场的粘性,采用动态重叠网格技术对受限水域的岸壁效应展开了数值模拟。随着计算机技术的快速发展,计算流体力学(CFD, Computational Fluid Dynamic)在船舶水动力研究中的应用越来越广泛。随着船舶粘性阻力计算方面取得的不断成功,人们开始探讨在操纵性数值研究中考虑流体的粘性。本文基于CFD技术,以系列60船型为研究对象,通过求解ANS (Reynolds Averaged Navier-Stokes)方程对船舶岸壁效应进行了数值模拟。其中,网格采用重叠网格技术,湍流模型采用SSTk-ω模型,求解算法采用PISO (Pressure Implicit with Splitting of Operators)算法,自由面的模拟采用单相Level Set方法。本文采用上述方法对系列60船型在近岸航行的深水和浅水中分别进行了数值计算。首先假设船舶静止不动,设置定向来流,模拟出了船舶的阻力系数、横向力系数和转首力矩系数,并将计算结果与他人的计算结果进行了对比,吻合度较高。然后放开船舶横荡、垂荡和纵摇三个自由度,对近岸壁航行的船舶进行了数值计算,得到了不同岸壁距离下的横移量,并分析了船速对其的影响,同时也研究了不同船速时船体压力的变化。本文采用的重叠网格技术,在保证计算精度的前提下,不仅简化了网格的生成,而且在船舶运动时只要生成新的网格插值信息即可,无需重新生成网格,这就大大的减小了工作量和计算量。本文的计算方法可以为进一步研究限制水域船舶操纵性提供借鉴；计算结果可以为驾引人员提供一定的参考,也可以为航道的疏浚、拓宽等提出理论上的建议。
[Abstract]:With the increase of ship scale, many waterways and the waters near the harbor become relatively narrow and become restricted waters.The hydrodynamic force and hydrodynamic moment of ships in these waters have also changed significantly, and many experts and scholars have done a lot of research on it.On the basis of previous studies, considering the viscosity of the flow field, the dynamic overlapping grid technique is used to simulate the shoreline effect in confined waters.With the rapid development of computer technology, computational fluid dynamics (CFD) and Computational Fluid dynamic (Computational Fluid) are widely used in ship hydrodynamic research.With the continuous success of ship viscous resistance calculation, people begin to study the viscosity of fluid in the numerical study of maneuverability.Based on the CFD technique, a series of 60 ship types are studied in this paper. The ship's shoreline effect is numerically simulated by solving the ANS Reynolds Averaged Navier-Stokes equation.Among them, overlapping mesh technology is used in mesh, SSTk- 蠅 model is used in turbulence model, PISO pressure Implicit with Splitting of operators algorithm is used to solve the problem, and single-phase Level Set method is used to simulate free surface.In this paper, a series of 60 ships are numerically calculated in deep water and shallow water by means of the above method.The resistance coefficient, transverse force coefficient and torque coefficient of the ship are simulated, and the calculated results are compared with those of others.Then the ship with three degrees of freedom, namely swinging, swinging and pitching, is numerically calculated, and the transverse movement of the ship at different shore distances is obtained, and the influence of ship speed on it is analyzed.At the same time, the variation of ship pressure at different ship speeds is also studied.The overlapping mesh technology adopted in this paper not only simplifies mesh generation, but also generates new mesh interpolation information while ship is moving, and does not need to be regenerated.This greatly reduces the workload and computation.The calculation method in this paper can be used for reference for further study on the maneuverability of ships in restricted waters, and the calculation results can provide some references for the stewards, as well as theoretical suggestions for the dredging and widening of waterways.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U661

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