波浪对非淹没水平圆柱作用的数值分析

Numerical investigation on free surface waves past partially submerged horizontal circular cylinders

该文选取URANS方程为控制方程结合k-?湍流模型,采用Level-Set方法追踪自由面,建立一种用于研究波浪与非淹没水平圆柱作用问题的二维数值模型。运用该数值模型对较小KC数条件下波浪与单个以及两个串联非淹没水平圆柱作用问题进行深入的探讨。结果表明,在单个非淹没水平圆柱工况中,不同波幅以及淹没深度条件下数值模型对水平圆柱竖直方向波浪力随时间的演化曲线做了准确预测,并揭示了波幅以及淹没深度对圆柱波浪力的影响规律;在两个串联非淹没水平圆柱工况中,圆柱间距对上游圆柱波浪力的影响较为明显:圆柱间距较大时,上游圆柱波浪力的大小以及演化规律与单个圆柱工况相近;而圆柱间距较小时,上游圆柱波浪力负向峰值明显增加。

In this study, a numerical model is carried out by solving the Unsteady Reynolds-Averaged Navier-Stokes（URANS） equations with the k-？ turbulence model. The Level-Set method is employed to model the free surface waves. The numerical model is performed to investigate free surface waves passing single or two partially submerged horizontal circular cylinders, and the vertical hydrodynamic forces of the cylinders under small Keulegan-Carpenter（KC） number are discussed in detail. The results show that the time history curves of vertical hydrodynamic forces predicted by the numerical model are in good agreement with the experimental measurement with different wave amplitudes or submerged depths in the single cylinder cases, and the effects of wave amplitude and submerged depth to the hydrodynamic forces have been revealed. After a further research in the two cylinders cases, the vertical hydrodynamic forces of the upstream cylinders are obviously affected by spacing between the two cylinders. When the spacing is large, the magnitude or evolutionary regularity of vertical hydrodynamic forces of the upstream cylinder are similar to the single cylinder cases; when the spacing is relatively small, the upstream experiences a larger magnitude of negative vertical hydrodynamic force compare to the large spacing cases.