多孔方型人工鱼礁绕流的数值模拟研究

数值模拟得到了5种不同来流速度(0.1 ～0.8 n/s)下的多孔方型人工鱼礁周围的水流场.过礁体中心的铅垂面上速度分布表明:①不同来流速度下,上升流的最大速度和平均速度均分别为来流速度的0.74倍和0.12倍,上升流最大高度均为礁体高度的2.6 ～2.7倍,背涡区的长度和高度均分别为礁体高度的4倍和1.25倍；②在靠近礁体背流面形成水流方向与来流方向相一致的透水区.过礁体中心的水平面上速度分布表明:①不同来流速度下,背涡区的长度和宽度均分别为礁体宽度的4倍和1.8倍；②在鱼礁内部形成水流方向杂乱的旋涡区.本研究还初步比较了多孔方型人工鱼礁绕流与无孔方型人工鱼礁绕流的流场效应异同点.

Study on numerical simulation of water flow past a porous square artificial reef

Numerical simulations are performed to obtain the water flow fields around a porous square artificial reef under the five different incoming velocities(0.1~0.8m/s).The numerical results of velocity distribution on the perpendicular flow plane passing through the center of the reef show that(1) under the five different incoming velocities the maximum and average velocities of the upwelling are 0.74 and 0.12 times of the incoming velocity,respectively,the maximum height of the upwelling is about 2.6 to 2.7 times of the reef height,and the length and height of the vortex region are 4 and 1.25 times of the reef height respectively;(2) a region where the flow direction is the same as that of the incoming flow is formed near the leeward surface of the reef.The numerical results of the velocity distribution on the horizontal flow plane passing the center of the reef reveal that(1) the length and width of the wake vortex region are 4 and 1.8 times of the reef width,respectively,for each of the five different incoming velocities;(2) vortex regions are also formed inside the reef.In this study,the similarities and differences with respect to the flow characteristics are also summarized preliminarily between the flow past a square reef without holes and the flow past a porous square reef.