Effect of Blade Profile on Performance of Squirrel Cage Darrius Turbine

Hydrokinetic turbine is a mechanical device which uses the kinetic energy of flowing water to generate the electrical power. For hydrokinetic turbine there is no need to construct the dam across the river or canal for storing the water to gene rate the power. Energy of flowing water stream is directly used to generate the power. It is advantageous in comparison to other renewable resources because it does not generate greenhouse gases. In India there are very less number of operating hydrokine tic energy plants, there are thousands of canals and enormous prospective for tapping hydrokinetic energy. Savonius hydrokinetic turbine is a vertical axis turbine which can be used in low stream velocity like river stream or canals. The present work deals with the performance improvement of savonius hydrokinetic turbine by changing the profiles of its turbine blades. A 3 bladed savonius hydrokinetic turbine having aspect ratio of 5.35 is designed and modeled in CREO 3.0. In order to study the performance of savonius turbine ANSYS FLUENT 16.1 is used. The behavior of the flow distribution in rotor has been analyzed and discussed in this investigation. Rotor is simulated for various rotational speeds and flow stream velocities. Three different blade profiles i.e, NACA 63(3)018, NACA 6409, NACA 4412 are investigated for their performance. The results obtained from numerical simulation of existing hydro kinetic turbine with turbine blades of NACA 63(3)018 profile are validated with the experimental results. It is found that the existing profile of this turbine can be replaced by NACA 6409 for getting better performance. The maximum value of power coefficient Cp for profile NACA 6409 is 0.5, for tip speed ratio (TSR) of 0.7.