Numerical analysis of hydraulic characteristics of resting pool in improved vertical slot fishway

Abstract

When fish swim upstream in the long-distance fishways, fatigue may occur, thereby affecting their passage efficiency and passage time. Therefore, constructing suitable resting pools within the fishway is essential. In this study, a diversion pile was introduced into the resting pool of the vertical solt fishway while altering its installation position. A three-dimensional re-normalization group k– ε turbulent mathematical model was then employed to analyze how the diversion pile with distinct positions affects the hydraulic characteristics in the resting pool under different slope conditions. The results show that with the diversion pile at the two-thirds position of the partition wall’s sidewall in the resting pool, the mainstream is effectively regulated to the central position, accompanied by a small degree of meandering. Under such an arrangement, although the diversion pile has an impact on the turbulent kinetic energy in the resting pool across various slope conditions, the influence is insignificant. Therefore, it is recommended to install the diversion pile at the two-thirds position of the partition wall’s sidewall in the resting pool, which can adjust the hydraulic characteristics of the resting pool and provide a large range of low-velocity areas for fish to rest, thereby facilitating the passage efficiency.