镂空型人工鱼礁流场效应的数值模拟研究

应用CFD软件对中空结构梯形台鱼礁和方型鱼礁在非定常流作用下的三维流场进行了数值模拟,揭示了两类鱼礁形成的上升流、背涡流的规模和强度,分析了单体鱼礁和组合鱼礁的流场差异。数值模拟结果表明:梯形台鱼礁上升流区最大速度约为来流速度的0.58~0.67倍、上升流区平均速度约为来流速度的0.15~0.19倍、而上升流区的最大高度为礁体高度的2.12~2.49倍,背涡流区平均速度约为来流速度的0.35~0.36倍、背涡流区的最大宽度约为礁体宽度的1.40~1.61倍、组合鱼礁背涡流区的最大长度约为礁体高度的4.06~4.17倍;方型鱼礁上升流区最大速度约为来流速度的0.56~0.61倍、上升流区平均速度约为来流速度的0.15~0.17倍、而上升流区的最大高度为礁体高度的2.22~2.63倍,背涡流区平均速度约为来流速度的0.30~0.35倍、背涡流区的最大宽度约为礁体宽度的1.75~2.00倍、组合鱼礁背涡流区的最大长度约为礁体高度的3.90~4.06倍。从流场调控效果来看,在相同模拟工况下,选择方型鱼礁比梯形台鱼礁能够更好地发挥鱼礁的环境资源修复功能。

Numerical simulation on features of flow field around hollow artificial reefs

The water flow pattern around hollow trapezoidal reef and hollow square reef in unsteady flow effect were investigated based on CFD numerical simulation, the scale and intensity of upwelling and wake vortex region were revealed, the flow field difference of monomer reef and combination reef were analyzed. The numerical results show that for trapezoidal reef ,the maximum and average velocities of upwelling were about 0.58 to 0.67 and 0.15 to 0.19 times of incoming velocity, the maximum height of upwelling was about 2.12 to 2.49 times of reef height, the average velocities of wake vortex region was about 0.35 to 0.36 times of incoming velocity, the width of wake vortex region was about 1.40 to 1.61 times of reef width, and the length of wake vortex region was about 4.06 to 4.17 times of reef height. For square reef, the maximum and average velocities of upwelling were about 0.56 to 0.61 and 0.15 to 0.17 times of incoming velocity, the maximum height of upwelling was about 2.22 to 2.63 times of reef height, the average velocities of wake vortex region was about 0.30 to 0.35 times of incoming velocity, the width of wake vortex region was about 1.75 to 2.00 times of reef width, and the length of wake vortex region is about 3.90 to 4.06 times of reef height. From the point of flow field control effect, under the same simulation condition, the square reef than trapezoidal reef could play a better environmental and resources repair function.