Numerical simulation of fish damage in a bulb tubular turbine with different guide vane openings

Abstract

Abstract Tubular turbines have advantages in developing low-head hydropower, however, the development of hydropower shouldn’t forget to maintain a balance with ecology. In this paper, a three-dimensional model of the flow channel of a low-head power plant bulb tubular turbine unit is established using Unigraphics NX, and the hydraulic characteristics and fish damage mechanisms of the turbine under different guide vane openings of 45∼85 mm in rated operating conditions are simulated and analyzed using STAR-CCM+, and it is found that the fish mainly suffers from impact damage and pressure damage in the downstream process with the highest probabilities of 15.73% and 15.72%, respectively. Furthermore, with the increase of the opening of the guide vane, the probability of shear damage to the fish first decreases and then increases, while the probability of pressure, pressure gradient, and impact damage all gradually increase, and the probability of all four types of damage reaches the highest when the opening of the guide vane is 85 mm. Although the unit will have a large output at large opening operating conditions, from the point of view of fish protection, it is better for such turbines not to be operated with large opening of the guide vane for a long time.