Vortex Dissipation Using a Hydraulic-Based Anti-Vortex Device at Intakes

In the present research, dissipating free surface vortices over the intakes by designing a hydraulic anti-vortex method is studied experimentally. In this method, an up-stream submerged water jet is used as a hydraulic-based anti-vortex mechanism. The imposed jet acts as a point source of external momentum to the formed free surface area. The added momentum changes the hydrodynamic balance of the vortex zone, and leads to instability and disability of the vortex to form and develop. Experiments were conducted on a projected horizontal pipe intake to investigate the efficiency of the proposed anti-vortex hydraulic device on dissipating and preventing formation of free surface vortices. Results show that the efficiency of the imposed jet is dependent on the jet linear momentum and vertical distance between the nozzle and intake positions. Moreover, the critical submergence of the intake can potentially reduce up to the nozzle submergence in which less than 10% of the jet momentum is required by decreasing nozzle submergence about 50%. Finally, an empirical equation is suggested to predict the critical submergence of the intake with respect to the jet linear momentum and the nozzle submergence.