Modeling the interaction of solitary waves and semi-circular breakwaters by using unsteady reynolds equations

A vertical 2 -D numerical wave model was developed based on unsteady Reynolds equations. In this model, the k-epsilon models were used to close the Reynolds equations, and volume of fluid( VOF) method was used to reconstruct the free surface. The model was verified by experimental data. Then the model was used to simulate solitary wave interaction with submerged, alternative submerged and emerged semi-circular breakwaters. The process of velocity field, pressure field and the wave surface near the breakwaters was obtained. It is found that when the semi-circular breakwater is submerged, a large vortex will be generated at the bottom of the lee side wall of the breakwater ; when the still water depth is equal to the radius of the semi-circular breakwater, a pair of large vortices will be generated near the shoreward wall of the semi-circular breakwater due to wave impacting, but the velocity near the bottom of the lee side wall of the breakwater is always relatively small. When the semi-circular breakwater is emerged, and solitary wave cannot overtop it, the solitary wave surface will run up and down secondarily during reflecting from the breakwater. It can be further used to estate the diffusing and transportation of the contamination and transportation of suspended sediment.     

液滴冲击液面过程中变形特征的实验研究

用高速相机拍摄了液滴以不同速度冲击液面的运动过程,测量了冲击过程中典型时刻液坑、中心液柱、次生液滴和次生液柱的几何尺寸,对这些几何尺寸的最大值与韦伯数(We)的关系进行了回归分析,结果表明:空间上,液坑的最大垂直深度、液坑的最大水平长度、中心液柱的最大高度、次生液滴等效直径和次生液柱的最大高度随We数增加呈线性增加;次生液滴等效直径是初始液滴等效直径的1.2～2倍;当200We220时,次生液滴冲击液面没有次生液柱生成,当360We713时,有次生液柱形成,220≤We≤360为过渡区;时间上,We数越大,运动过程中液坑的大小和中心液柱的高度变化越快,液坑和中心液柱持续时间越长,中心液柱达到最大高度的时刻以及破碎生成次生液滴的时刻也越晚。     

用时变雷诺方程模型模拟孤立波与半圆型防波堤的相互作用

以时变雷诺方程为控制方程,用k-ε模型封闭该方程,采用体积函数(VOF)方法来跟踪波动自由表面,建立了二维垂向波浪数学模型,并用已有的实验资料进行了验证．随后用该模型模拟了半圆型防波堤与孤立波在淹没、平顶水位、完全露顶且不越浪3种典型工况下的相互作用过程．得到了半圆堤附近的流场、压强场和波面的变形过程．结果表明,在淹没状态下,半圆堤背浪面的底部会产生涡旋;平顶水位时,由于越浪的冲击作用,在半圆堤的背浪面将逐渐形成一对较大的涡旋,而半圆堤背浪面的底部,速度始终相对较小;而在露顶不越浪时,半圆堤的迎浪面会出现波浪的二次爬升的现象．为进一步研究结构物附近的污染物的输移扩散和泥沙运动提供基础．     

基于多孔介质模型的养殖网箱周围流场特性研究

为探讨鱼类养殖网箱对周围海域流场的影响,基于雷诺时均方程和Realizable k-ε湍流模型,耦合多孔介质模型,建立了研究鱼类养殖网箱周围流场的三维水动力模型.根据典型养殖场的实际数据,分别对仅网衣作用、仅鱼类作用及网衣和鱼类共同作用下网箱周围流场进行数值模拟.结果表明综合考虑网衣和鱼类的作用时,网箱下游流速衰减最大...