Optimal Design of a Marine Current Turbine Using CFD and FEA

Abstract

Ocean currents that are produced due to motion of tides can be utilized in power extraction by using suitable turbines. The turbine should be structurally and hydrodynamically strong. In this paper, a 0.8 m horizontal axis marine current turbine (MCT) with three blades is analyzed. A 3D CAD model of a turbine is optimized using CFD and FEA tools. The performance of the turbine is based on the coefficient of power; however, the turbine should resist the loads acting on it. The fatigue load damages the turbine which is mainly due to wave loads and it must be evaluated to avoid the cost of replacing a new turbine. Only a turbine with high power coefficient and good material strength will result in a favorable design. The parameters like pitch angles, number of blades, and turbine material are modified to study the performance and structural stability of the turbine. The detailed CFD study including boundary conditions and methodology has contributed to get an insight of the flow physics. The best suitable pitch angle and number of rotor blades for the turbine are analyzed and discussed. The optimized turbine has two rotor blades with a pitch angle of 19.5° and has achieved a significant 25% increase in CP. Later, different materials are chosen to identify the variation in stress and tip deflection of the turbine blades. This will direct toward a safe design of the turbine blades.