Influence Of Blade Microstructure On Drag Reduction Performance And NC Machining Tool Path Planning

With the emergence of the world energy crisis,the space and aviation industry of high fuel oil rate has posed a challenge.As an important component of aero engine,the performance of impeller parts directly affects the overall performance of the engine.Therefore,it is a very important task to study the influence of the microstructure of the blade surface on the drag reduction performance in order to reduce the loss of flow and energy dissipation and improve the performance of the blade.The following work has been done in this thesis:(1)Study on the microstructural drag reduction performance of the blade surface.In this paper,the FLUENT software is used to simulate the drag reduction performance of four kinds of microstructures with different shapes and sizes.The relationship between the drag reduction effect of the microstructure and its shape and dimensionless size is obtained.The results show that the trapezoid groove has the best drag reduction effect,and the maximum drag reduction rate reaches 12.12%when it is in the case of s+=15.5.Then the trapezoid groove was applied to the blade surface of the impeller,and the drag reduction performance of the blade surface was verified by simulation.The results showed that the drag reduction rate of the trapezoidal groove could reach 8.53%on the suction surface of the blade.(2)Tool path planning of blade surface microstructures.First,the three-dimensional model of the impeller is set up.The cutter is designed according to the shape and size of the machining microstructure.Then the influence of the change of the cutter axis vector on the machining deformation is studied.The microstructure area is reconstructed with the target of reducing the machining deformation,and the path of the blade surface microstructure is planned.After that,post processing of the cutter position information is processed,and the NC machining program is obtained.(3)The simulation and experiment of the microstructural machining of the blade surface.First,the rough machining and finishing NC machining program of the impeller is generated by using UG software.Then,the VERICUT software is used to simulate the tool path of UG generated impeller processing program and post processing microstructural processing program.Finally,all NC programs are processed on the five axis CNC machine tool of our laboratory,and the feasibility of tool path planning is verified.