Water Resources and Power

As an important flow-guiding component of the hydraulic turbine and adjacent to the runner, the guide vane, has a trailing vortex structure that enters the downstream runner channel and affects the operational stability of the unit. To this end, a variable cross-section bionic guide vane with smooth leading edge is proposed, and the hydrodynamic characteristics of the guide vane itself, the pressure pulsation characteristics in the wake area, and the distribution characteristics of the flow field around the guide vane are analyzed at different angles of attack and different numbers of leading edge projections. The results show that the hydrodynamic moment and radial force of the bionic guide vane are greatly reduced relative to the original guide vane at three different angles of attack, with the maximum moment decreasing by 51.2%(angle of attack of 20°, sin-two model) and the maximum radial force decreasing by 40.6%(angle of attack of 20°, sin-two model). The pressure pulsation of the sin-three bionic guide vane model is significantly reduced for different monitoring points at the same height of guide vane, and the pressure pulsation in the wake area is significantly reduced for different monitoring points at the same height of guide vane. The pressure pulsation of sin-three bionic guide vane is reduced significantly, and the amplitude of pressure pulsation of each guide vane model was approximately the same for different monitoring points at the same guide vane height. sin-three bionic guide vane has the best inhibition effect on the large-scale flow separation of the negative force surface, and even at a large angle of attack of 30°, the flow separation inhibition is also shown to be excellent. The bionic-based passive flow control measures are important references for optimizing the operational stability of the hydroelectric unit when operating at small flow conditions(or when the guide vanes are at large angles of attack).