Design Of Floating Horuzontal Axis Power Flow Tuebine Blades And Study Of Hydrodynamic Characteristics

With the progress of human society,a large amount of available traditional energy resources are gradually exhausted.Countries around the world began to increase efforts to develop and utilize renewable energy.Tidal current can be a predictable,large reserves of renewable energy,causing widespread concern around the world.Floating horizontal axis tidal current power generation device has the characteristics of simple structure,suitable for all kinds of sea depth,easy to move and maintain,etc.,which has attracted the attention of new energy scholars all over the world.Turbine blades are the core components of power flow devices,which directly affect the power generation and service life of power flow devices.Therefore,the study on the influence of floating horizontal axis power flow on turbine blade performance under different working conditions has important reference significance for turbine blade structure design,installation and use.In this paper,the design of turbine blades with excellent performance is mainly studied,and the hydrodynamic performance changes of turbine blades under the condition of bias flow and free liquid level are studied.In this paper,the main theories of turbine blade design are firstly studied,and airfoil theory and blade element momentum theory are applied.Wilson method was used to study the parameters of turbine blades,and appropriate inducer parameters were selected.In order to ensure the optimal Angle of attack of each blade element,the parameters of turbine blades are modified in consideration of structural stability.Coordinate transformation and 3d modeling software are used to establish the 3d model of turbine blades.Secondly,through CFD method,STAR-CCM+ is used to establish the numerical model of turbine blades,and the known test data are used to verify the validity of the established numerical model.Finally,the numerical model of turbine blade under ideal conditions,yaw flow and free liquid level is established to analyze and study the hydrodynamic performance.The influence rule of turbine blade hydrodynamic performance under different working conditions is analyzed.Under ideal conditions,the hydrodynamic performance of turbine blades and BDA symmetrical blades is compared and analyzed under different cusp velocity ratios.Energy efficiency,load efficiency and turbine blade pressure and flow field characteristics under bias flow condition and free flow condition.In this paper,turbine blades are designed with S825 airfoil,and hydrodynamic performance of S825 turbine blades is studied by verifying CFD method.The calculation results show that the energy efficiency of S825 turbine blade is 42.3%,which is 3.8% higher than that of BDA symmetrical airfoil.In the case of bias flow,as the yaw Angle of S825 turbine blade increases,the energy efficiency and axial load coefficient of turbine blade gradually decrease,and the periodic load on a single turbine blade increases.Under the condition of free liquid level,the influence of free liquid on turbine blade hydrodynamic performance decreases with the deepening of water depth.When the water depth is the impeller diameter,it has little influence on the hydrodynamic performance of turbine blades.The energy efficiency and load coefficient decrease with the deepening of water depth,and the instantaneous fluctuation of energy efficiency and load coefficient decreases.