PERFORMANCE INVESTIGATION OF DIFFERENT HYDROKINETIC TURBINES UNDER DIFFERENT SITE CONDITION

Abstract

Energy crisis and the consumption of conventional energy resources have paid a great attention towards the use of renewable energy. The conventional energy sources are depleting day by day. The alternate energy resources are hence required. This is where the renewable source of energy comes into picture. The growth of civilization has been linked to our ability to capture and use the force of flowing water to our benefit. As lot of potential is available in flowing streams, so natural power available in streams has gained keen interest in electricity production for many years. Energy of waterways is mainly extracted by means of conventional hydropower plants that require some kind of a dam or reservoir. In the past, hydropower has been seen as a viable resource apparently to have little effect on the environment as river flow modifications and temperatures cause adverse effects to fish and other marine life. Therefore, the tidal energy systems were adapted for river energy extraction, which have their origins in wind energy extraction technologies. Hydrokinetic energy is one of the most emerging technologies for power generation, it has gained keen interest of the researchers because of unique properties of water such as higher specific weight, higher momentum than air for same velocity and conditions. Hydrokinetic energy can be deployed in run of rivers, streams or waterways, where sufficient potential in the form of kinetic energy is available. Under present dissertation work analytical and numerical investigation of different hydrokinetic turbines have been carried out through literature survey and factors on which site conditions depend for the hydrokinetic turbines. The output parameters of the hydrokinetic turbines have been analyzed based on the variation in the site conditions like flow velocity, free surface, blockage effect and bed forms. The parametric analysis of Savonius (Cross Flow) hydrokinetic turbine is conducted using the Computational Fluid Dynamics (CFD), k-epsilon realizable model in its transient state. By fixing different parameters like blockage ratio, TSR, number of blades, Reynolds number and flow velocity, the effect of installation of the turbine at different installation (Clearance Ratio) conditions was analyzed. The turbine yields its maximum performance corresponding to 0.51 value of clearance ratio at 0.8 TSR. Further the effects of installation parameters have also been analyzed at different operating conditions (TSR)