| Aeroengine manufacturing often integrates the highest technologies of manufacturing.Its manufacturing process is more like the presentation of industrial manufacturing art.The drag reduction mechanism and its machining methods of bionic surfaces has come to the visons gradually.Researches shown that the bionic surfaces have a good performance in fluid drag reduction.The application of bionic drag reduction surface in the processing of aeroengine blades is of great significance to improve the aerodynamic performance of aeroengine.So far,the processing of bionic surface mainly depends on laser processing and electrochemical processing.Although the shape forming of bionic structure is ideal,but the processing efficiency is low and the processing cost is high.So it can't be effectively applied to mass production in factories.As a common finishing method of aeroengine blades,belt grinding has the advantages of precise processing,high efficiency and low cost.So this paper presents a bionic surface belt grinding method for the machining of titanium alloy aeroengine blades.The main contents of this paper are as follows:(1)A bionic surface characterization model was established,which was in accordance with the characteristics of belt grinding.Based on the second vortex group theory and the outburst height theory,the principle of fluid wall drag reduction is analyzed.The results show that the shape of rib structure affects the outburst height h_p and the effect of fluid drag reduction.According to the characteristics of abrasive belt grinding,three kinds of parametric models of bionic rib structure,V-shape,trapezoid and wave shape,are established to represent the height and angle of rib structure.(2)The aerodynamic performance of the curved blade model with bionic rib structure was simulated and analyzed.In this paper,27 models of three groups of bionic rib models were built on the curved surface model of a certain aircraft blade,and the characteristics of air flow on the surface were simulated and analyzed.According to the simulation results,the hydrodynamic differences between the ribs with different cross-section shapes and the top angle of ribs were analyzed,and it was concluded that the optimal surface of the bionic ribs of blades was V-shaped cross-section structure and the top angle was 45°.(3)The grinding method of bionic surface abrasive belt of aircraft blade was determined.Starting from the removal of bionic surface abrasive materials by abrasive belt grinding,a parameter model for the removal of bionic rib surface materials by abrasive belt grinding was established.The method of belt grinding on bionic surface of aeroengine blade was determined,and the calculation of the path distance of belt grinding bionic rib surface was optimized to ensure the integrity and consistency of the grinding surface structure.(4)The abrasive belt grinding evaluation experiment of bionic surface with high aerodynamic force of titanium alloy aeroengine blade was carried out.The experimental platform of bionic surface belt grinding with high aerodynamic force for titanium alloy aeroengine blade was built and the belt grinding experiment and detection were completed.The experimental results shown that the bionic surface grinding method with abrasive belt could process the surface with V-shaped rib structure on the surface of titanium alloy blade.The top angle of rib was distributed between 29°and 76°.The whole surface shown good drag reduction effect. |
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