Recently, the utilization of low-head hydroelectric technologies has received a great attention for the expansion of distributed power systems into isolated regions that are difficult to be connected to the electrical grid, especially in developing countries. The use of gravitational vortex hydropower systems can be a renewable and suitable option to expand electricity access and promote development in these remote regions, which are concomitantly rich in hydric resources, due to this system can operate with low head without the need of a large reservoir and installation area. In this study, the performance of the inlet channel and basin of a gravitational water vortex turbine was investigated. Two inlet channels and two basin geometries were numerically analysed in Ansys Fluent software. The velocity and vortex height were calculated and compared for each setting. It was found that the inlet channel with conical basin tended to produce more symmetric vortex in comparisons with that generated by the cylindrical geometry. Additionally, the conical basin maximized the flow velocity on the water surface area.

A gravitational water vortex hydraulic turbine (GWVHT) is a low head hydropower technology with a vertical runner for extracting energy from the water vortex. To determine the optimal position (h) of the runner for the hydropower plant efficiency to be increased, a runner in three different positions was compared using computational fluid dynamics (CFD). The position of the runner was a function of the basin height (H). The maximum efficiency (44.15%) was established when the runner was located at 60% of H. The angular velocity associated with the maximum efficiency was 14 rad/s.

Gravitational water vortex turbine (GVT) is a run-of-the-river hydroelectric system used for generating electricity in the absence of a large dam and a reservoir; i.e., GVT generates power using the water natural flow rate. Recently, the development of GVT is gaining a growing interest within the scientific community concerning the advantages associated with the technology in the process of electric power production. This work describes the design of an experimental facility for the characterization of a GVT in order to understand in a detailed way the effect of the variation of hydrodynamic and geometric parameters on the performance curve of the turbine. The experimental results demonstrated that a wider vortex is generated at lower channel inflow velocities. Additionally, a maximum efficiency of 0.495 at 140.25 rpm was found for the GVT tested.