Water Flow Velocity Driven Modified Savonius Hydrokinetic Turbine

Abstract

Hydrokinetic turbines are new technologies to harness the kinetic energy of river streams without impounding the concreate structure across the natural flow of water. These turbines can provide an alternative solution to generate the clean and sustainable energy from rivers, natural water streams, and tidal or marine currents where the water flow velocity is relatively uniform and one directional. This turbine can also be installed as a standalone off-grid power generation for domestic houses, especially for the houses in villages, which is located far from the main grid. This study is aimed to quantify the high dynamic interaction and complexity of the turbine blades and the turbulent flow to optimize the power coefficient and to study the critical prerequisites for utilizing the full potential. Such hydrokinetic turbine is still in the research phase and yet to be commercially installed in India. Savonius hydrokinetic turbine (SHKT) is the simplest of all hydrokinetic turbine. It can be easily construct and repair by local inhabitants and can be even easily dispose to the environment. In this study, CFD analysis is performed on a SHKT with circular blades, 90º helical blades, 180º helical blades and modified Savonius hydrokinetic turbine by varying the blade arc-angle and blade shape factor to analyse the parameters influencing the power coefficient. Unsteady Reynolds Average Navier-Stokes equation (URANS) solver has been applied for numerical analysis with realizable k-ε (Enhance wall Fn.) turbulence model. The study compared to the circular turbine shows that 180º helical, modified SHKT and 90º helical SHKT results in an increase of 6.5%, 16.1%, 33.6% in power coefficient.