Wave-Current Turbine Design And Hydrodynamic Analysis

As research hotspots,Wave-Current turbine components and mechanism design are important for marine energy turbine technology development.The parametric design of blades,turbine performance and structural parameters of the shroud have become the focus for many scholars.Based on the development of existing marine power turbine,this paper proposes a Wave-Current turbine device to improve energy capture efficiency and energy conversion efficiency.The main research contents are as follows:Based on the design principle of the turbine,a direct-drive permanent magnet generator is proposed.The turbine blade is directly coupled with the motor shaft to form an integrated structure.According the rotation,the blade transmits directly to the blade,and the drives the generator to generate electricity,which greatly reduces the energy consumption of the overall system.Besides,a shroud with a flare improves the efficiency of the overall system.In order to reduce the loss of the stator core,the stator core is made of silicon steel sheet.And the inner rotor structure is adopted.The semi-open stator slot structure increases the structural space of the coil winding.The motor designed in this paper is equipped with permanent magnets,the magnetic field of which is provided by permanent magnets,removing the excitation winding and brush.The magnetic flux density is increased,so that the volume of the motor can be further reduced and the whole device is more compact.The energy consumption is reduced,at the same time,the stability of the motor work improves the efficiency.Based on the design theory of wind airfoil and combined with the hydrodynamic characteristics of the turbine,a S blade suitable for ocean energy generation is developed.According to the parameter-design and the theory of fluid mechanics,the threedimensional drawing software SOLIDWORKS was used to draw the three-dimensional model after obtaining the parameters of each element of the blade.Then by studying the rationality of the blade parameters and analyzing the influence of different blade numbers on turbine,the numerical simulation method is combined with the ANSYS simulation to obtain and analyze the velocity vector diagram and pressure cloud map of different blades.Combination with the design principle of the wind diffuser,a shroud with different opening angles is designed.By numerical simulation.the software FLUENT is used to analyze the flaring angle parameters of the shroud,and the flaring angle of the shroud is set to 15°,20°,25°,30°,and 35°.The research shows that within a certain range,with the increase of the angle of the flaring,the internal turbulence effect formed inside the shroud is reduced.Low pressure zone formed inside is more obvious,which accelerates the velocity of the fluid.During the Ansys simulation of the shroud,it was found that there were some eddy currents on the upper and lower sides of the shroud.When the direction of the incoming flow changes within a certain range,an asymmetrical force is generated in the radial direction of shroud,and energy absorption efficiency of the blade also decreases.According to the output power and efficiency diagram of simulation test,it can be seen that as the opening angle increases gradually within a certain range,the output power and power generation efficiency increase first and then decrease,and when the flare angle of the shroud is 25°,output power and power generation efficiency are the highest,and the overall turbine system efficiency is up to 35%.Based on the structural design and simulation,the performance test of the motor,the sink test and the offshore test are carried out.Taking into account the unstable power generated by the turbine due to unstable waves,the MATLAB simulation method is used to design a power processing simulation system.Through the sink test and the offshore test,the S-shaped blade has two-way adaptability,and the motor has a good low-flow self-starting performance.In this paper,a wave-current turbine is designed by parametric design,ANSYS simulation and MATLAB modeling.The performance of the turbine is verified by motor test,sink test and offshore test,which provides reference value for the research of marine power turbine.