内孤立波环境下柱体的受力特性

针对以往孤立波对柱体作用研究多只针对柱体的整体受力开展,少有研究精细获取柱体不同部位受力特性的问题,借助三维大涡模拟(LES)数值波浪水槽,通过提取柱周流场及压强分布,得到柱体所受压差阻力及黏滞力的垂向分布,对柱体在孤立波环境中的受力特性进行了分析,并采用多元线性回归分析,构造综合影响参数分析了柱体受力特性,构建了柱体受力系数经验表达式。结果表明:上下层水体中方柱所受压差阻力约分别为圆柱的1.5倍和3.5倍;作用于柱体上的黏滞力比压差阻力小1或2个数量级,可忽略流体的黏性效应;综合影响参数与相对波幅正相关,与上下水深比负相关。

Mechanical properties of cylinders under environment of an internal solitary wave

Most previous studies focused on the overall force on a cylinder, and the detailed mechanical characteristics for different parts of a cylinder were less studied. A 3-D numerical wave flume was used to investigate the internal solitary wave forces acting on cylinders by large-eddy simulation(LES). Through analyzing the hydrodynamic characteristics and the pressure distribution around cylinders, the detailed vertical distribution of the pressure drag force and viscous force was obtained. Based on multi-linear regression analysis, the comprehensive impact parameters were constructed to establish an empirical function of the force coefficients for the cylinders. The results show that the pressure drag on a square cylinder is 1. 5 times more than that on a circular one in the upper layer, while the pressure drag on a square cylinder is 3. 5 times more than that on its circular counterpart in the lower layer. The viscous force is 1 or 2 order of magnitudes smaller than the pressure drag, which means that the viscous force can be ignored. The comprehensive impact parameters show a positive correlation with the relative wave height, and show a negative correlation with the upper and lower water depth ratio.