透空式开孔防波堤水动力特性的数值研究

Numerical study on hydrodynamic characteristics of perforated Pile-supported vertical wall breakwater

利用开源软件OpenFOAM建立波浪数值水槽,在规则波作用下,研究了开孔透空式防波堤水动力特性的变化规律。利用物理模型实验对数值水槽的可靠性进行验证。结果表明开孔位置只在前挡板的情况下,防波堤的透射系数会先减小后增大,在开孔率为4%透射系数达到最小,前挡板所受到总的水平波压力和反射系数会一直减小。开孔方式和开孔形状对防波堤的水动力特性影响较小,开孔率对其影响较大。当保持开孔面积恒定的情况下,对只在前档板开孔和前后开孔面积各一半的情况进行了比较,并进一步分析了水动力特性随着前后挡板开孔形心垂直距离D的变化关系。结果发现,前后挡板都开孔要比只在前挡板开孔的情况好很多。随着D增大,透射系数会减小,总的水平波压力和反射系数会变大。当D大于0.05 m,透射系数、反射系数和总的水平波压力变化很小。

A numerical wave flume was established by source software OpenFOAM.Then the hydrodynamic characteristics variations of perforated Pile-support vertical wall breakwater were studied under the regular wave.And the reliability of the numerical flume was tested by the physical experiments.As a result,when the perforated position is only at the front barrier,the transmission coefficient would decline and then increase and as the perforated ratio is up to 4%,the transmission coefficient reaches the minimum value.The total horizontal wave pressure on the front barrier and the reflection coefficient are reduced.The change of the hydrodynamic characteristics is not related to mode and shape of the holes.This result is mainly attributed to the perforated ratio.When the perforated area is a constant,the total perforated area at the front barrier and the half perforated area at each of barriers are compared.Further the relationship between the hydrodynamic characteristics and the vertical distance between the centroids of the holes at the perforated barriers D is analyzed.The double barriers perforated breakwater is much better than the front barrier perforated breakwater.As the D increasing,the transmission coefficient decreases,with the total pressure and reflection coefficient increasing.However,when the D is greater than 0.05 m,transmission coefficient,reflection coefficient and horizontal wave pressure are not any more change.