Abstract Flow past a circular cylinder located between free-surface and wall boundaries is modelled numerically using non-uniform particle size incompressible smoothed particle hydrodynamics (SPH). Several enhancements including Rhie and Chow interpolation, colour function-based free surface tracking, and modified particle shifting are introduced to increase the accuracy and efficiency of the method. A parameter study at constant Reynolds number, Re = 150 , examines the influence of Froude number ( Fr = 0 . 2 − 0 . 6 ), submergence ratio ( H ∕ D = 0 . 5 − 1 . 0 , where H is the distance between the apex of the cylinder and undisturbed free surface, and D is the cylinder diameter), and bottom gap ratio ( G ∕ D = 1 . 0 − 5 . 0 , where G is the distance between the base of the cylinder and the bed) on the ambient free-surface flow pattern and hydrodynamic force on the cylinder. It is found that the vortex shedding pattern depends on all three parameters. As the Froude number increases for fixed submergence ratio and bottom gap ratio, vortex shedding is eventually suppressed. As the submergence and bottom gap ratios increase, the threshold of vortex shedding suppression shifts to higher values of Froude number. The mean drag coefficient depends on the submergence ratio and bottom gap ratio but is independent of Froude number. Meanwhile, the lift coefficient depends on submergence ratio and Froude number but is independent of bottom gap ratio. Spectral analysis of force and free-surface elevation time signals shows that the free-surface deformation and lift force are closely related during the vortex shedding regime.

中文翻译：

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平面壁与自由表面之间流过水平圆柱体的不可压缩SPH模拟

摘要 流过位于自由表面和壁面边界之间的圆柱体的流动使用非均匀粒径不可压缩平滑粒子流体动力学 (SPH) 进行数值模拟。引入了多项增强功能，包括 Rhie 和 Chow 插值、基于颜色函数的自由表面跟踪和改进的粒子移动，以提高该方法的准确性和效率。在恒定雷诺数 Re = 150 下进行的参数研究检查了弗劳德数 (Fr = 0 . 2 − 0 . 6 )、淹没比 ( H ∕ D = 0 . 5 − 1 . 0 ，其中 H 是距离的影响)圆柱顶点与未受干扰的自由表面之间的距离，D 是圆柱直径）和底部间隙比（ G ∕ D = 1 . 0 − 5 . 0 ，其中 G 是圆柱体底部和床之间的距离）环境自由表面流动模式和圆柱体上的流体动力。发现涡旋脱落模式取决于所有三个参数。随着固定浸没比和底部间隙比的弗劳德数增加，最终抑制涡旋脱落。随着淹没和底部间隙比率的增加，涡旋脱落抑制的阈值转移到更高的弗劳德数值。平均阻力系数取决于浸没比和底部间隙比，但与弗劳德数无关。同时，升力系数取决于淹没比和弗劳德数，但与底部间隙比无关。