Enhancing the performance of gravitational water vortex turbine by flow simulation analysis

Abstract

Gravitational Water Vortex Power (GWVP) plant is a favourable micro-hydro extraction method due to its simplicity and compatibility with ultra-low hydraulic head applications. However, the GWVP turbines are less efficient than other commercial hydro turbines. This study mainly focuses on improving the performance of the vortex turbine setup inside a conical basin structure using Computational Fluid Dynamic (CFD) analysis for different configurations of vortex turbine blades. After validating the ANSYS CFX CFD setup with available experimental results, the parametric study of the turbine was carried out based on four parameters; blade inclination, turbine height, vertical twist and horizontal curvature. The relationship between flow behaviour and performance was analysed in each case, considering the air-water interface, pressure and velocity fields. The blade inclination, similar to the conical basin inclination, yielded enhanced performance, and an optimal blade height was identified for this setup. The horizontally curved blade showed a slightly better performance than the vertical twist blade for the original design of the conical basin. However, when the drain diameter of the basin structure has increased, the performance of the vertically twisted blade showed good performance resulting in 55.3% efficiency while maintaining a stable air core.