Research On The Optimization Analysis Of A Savonius Rotor Under The Wave-Current Condition Based On CFD

In current days,we are facing the challenge of limited energy.Therefore,the renewable energy such as ocean energy and wave energy has been paid more and more attention.Nowadays the main way to extract energy from wave is still using vertical turbine.Savonius rotor is a common vertical turbine,it has simple structure and it's easy to made,for those features,Savonius rotor has been wildly used in practical programs.Usually,Savonius rotor is used in wind circumstance,in this article,this rotor is applied in wave-current coupling condition,in order to improve the performance of a Savonius rotor,a series of modified Savonius elliptical blades was introduced.Influence of the blade ellipticity on the power efficiency of the rotor was investigated with a transient computational fluid dynamics(CFD)method over a range of revolving speed.After the simulation,a series experiments was carried out to confirm the results of simulation.In this article,the main work include:Firstly,the theory of hydromechanics was used to analyze the movement of the Savonius rotor and established the dynamic model of the rotor.A formula about the power efficiency and ellipticity was carried out which indicated that the power efficiency is related to the ellipticity.Secondly,based on UDF and volume of fluid theory,build a numberical wave flume and make a series models of Savonius rotor by change one of their axises.Then,simulated models were built by Ansys workbench.Mesh and boundary conditions were set in ICEM CFD,UDF program control the mesh to form the wave-current coupling condition.A series simulation has been made to investigate the performance of different elliptical Savonius blades and find out the best ellipticity.At last,a series of experiments have been carried to validate the conclusions of the numberical analysis.The results indicate that: with the ellipticity increases,the power efficiency increases first and then decreases,the rotor with a ellipticity of 0.61 generates the maximum power coefficient 0.19,which is 5.55% higher than a conventional Savonius rotor.