Effect of the Inlet Velocity on the Behavior of Gravitational Water Vortex for Electricity Generation

Abstract

Climate change is primarily driven by the use of fossil fuels. However, renewable energies, such as hydropower, cause deforestation and population displacement, and their energy usually does not reach remote areas. Gravitational Water Vortex Power Plants (GWVPPs) are a hydroelectric alternative that does not alter the course and flow of rivers and can be used in areas not connected to the power grid. This work focused on studying the influence of the inlet velocity on the morphology of water gravitational vortices (GWVs) and their fluid-dynamic properties such as pressure, velocity, and volumetric fraction. The methodology employed consisted of using the OpenFOAM CFD software to run the simulations, where the channel input velocity was changed and the contours of velocity magnitude, static pressure, and volumetric fraction in the basin were plotted. The results of the investigation showed that well-developed vortices were obtained from an input velocity of 0.03 m/s, while the higher speeds (0.05 m/s and 0.06 m/s) produced more uniform velocity magnitude contours. Although all vortices have an air core at discharge, high inlet speeds induce a greater likelihood of weak vortex formation. Finally, the conclusions of this work are that high speeds also lead to higher volume fractions inside the basin, which can be practical for water vortex power generation systems due to their higher inertia. The input velocity also influences the behavior of the height, curvature, and tangential speed of the free surface with the radius.