环形波纹钢管涵洞式鱼道水力特性数值模拟

Numerical Simulation on Hydraulic Characteristics of Culvert Fishway with Annular Corrugated Steel Pipe

环形波纹钢管涵洞式鱼道内波纹的粗糙度可以使边界附近产生足够低的流速,鱼类可以由此游向上游。对3种流量0.05,0.07,0.09 m^3/s,3种埋深0D,0.1D,0.2D,坡度0.4%工况下,环形波纹钢管涵洞式鱼道内水面线、流速场和紊流场分布分别进行了数值模拟研究。结果表明:环形波纹钢管涵洞中,高流速区(无量纲流速大于0.9)位于涵洞过水断面中心区域,高紊流区(紊流强度大于0.2)位于水面中心附近。在涵洞底部边壁附近较大区域内,由于流速较小,紊流强度也较低(紊流强度小于0.1),鱼类可以由此顺利完成上溯。相比无埋深式涵洞,嵌入式涵洞内平均流速较小,紊流强度变化较为平缓,更有利于鱼类的洄游。

The roughness of annular corrugated steel pipe fishway could generate sufficiently low flow velocities near the boundary, which facilitates fishes to immigrate towards the upstream. In this paper, the water surface line, flow velocity field, and turbulent flow field in the annular corrugated steel pipe culvert fishway are simulated under dif- ferent conditions （flow rate 0.05 m3/s, 0.07 m3/s and 0.09 m3/s, embedded depth 0D, 0.1D and 0.2D, and slope gradient 0.4%）. Results show that high velocity field （dimensionless velocity greater than 0.9） is located in the central area of the cross section of the culvert, and high turbulent flow field （turbulence intensity greater than 0.2） is located near the central area of the water surface. In large areas near the side walls of culvert bottom, due to rela- tively low velocity, the turbulence intensity is relatively low （less than 0.1 ） and fishes could complete migration u- sing this passage. Compared with non-embedded culverts, the embedded culvert has lower average velocity and gen- tle variation of turbulence intensity, therefore it is more conducive to fish migration.