CFD evaluation of performance of Gravitational Water Vortex Turbine at different runner positions

Abstract

A free vortex is a region in which flow revolves around an axis line that requires a small head to form, about 0.7 m-2 m. In Gravitational water vortex turbine, water assuming to be non-rotational and inviscid passes through an open channel and enters the basin tangentially where it forms a powerful vortex. Then, the dynamic force of water is transmitted by the vortex to the turbine via mixed flow, impulse and reaction, phenomena. It can be a promising cheap and effective solution to compliment recent strives for renewable energy technologies. This paper deals with design and development of a prototype Gravitational water vortex turbine and analysis with computational and experimental methods. Initially, the computational method focuses on determining maximum tangential velocity of water achievable in the setup without turbine. And further computational analysis is carried out for the setup with turbine to determine performance characteristics by adjusting the runner heights in three positions. This computational study is validated by performing experimental testing by fabricating test rig. It showed best efficiency when runner was at lowermost portion of the conical basin.