Research On The Performance Of Savonius Rotor Under The Condition Of Wave-current Coupling Effect

Ocean energy,as a new type of clean energy,is renewable,has huge reserves and strong detectability.Under the background of over-exploitation of traditional energy,how to effectively utilize ocean energy has become an urgent problem to be solved.At the present stage,the Marine energy development technology is mainly to use the turbine to convert the Marine energy into mechanical energy and then convert it into electrical energy through the power generation device.Savonius type turbine is a common vertical axis turbine with simple structure and has a wide range of applications in engineering.However,the power coefficient of Savonius turbine is low,and the maximum power coefficient can only reach 0.34 in theory.Therefore,how to improve the power coefficient of the turbine and improve the performance of the turbine has become the focus of researchers in recent years.In this paper,on the basis of the traditional S-type turbine blade,the twisted blade is designed,and a numerical wave pool is established.The torque coefficient and power coefficient of the blade with torsion Angle are analyzed under the condition of pure flow and wave-flow coupling,and the performance of the blade is studied.Firstly,a suitable Savonius blade research method was selected by referring to the literature,and a numerical model of S-shaped blade with different torsional angles was established by using Solidworks software.Under pure flow conditions,the changing trends of blade torque coefficient and energy capture coefficient at different torsional angles were compared,and then the optimal blade torsional Angle value was obtained by fitting the data.Then referring to the related theory of wave,using the VOF method in the Fluent software to establish a numerical wave tank model,compare the wave pool on the surface of the medium wave after the fifth order Stokes theoretical calculation and numerical solutions can be seen that the numerical wave tank wave spread evenly,within the band elimination wave attenuation,wave wave attenuation effectiveness can achieve the desired effect,can meet the needs of subsequent calculations.Finally,an S-shaped blade with torsional Angle was added into the numerical wave flow pool,and the blade performance was studied from two aspects of torque characteristics and power characteristics under the condition of changing wave height,wave period and flow velocity.The results show that the blade performance is improved to a certain extent in the case of wave-flow coupling,and the performance is improved more obviously with the increase of wave height.In wave pool,the decrease of wave period and flow velocity will increase the wave wave degree,and there is a coupling effect between blade and wave.At this time,the torque coefficient and energy capture coefficient of blade increase,and the blade performance is improved.