Design Analysis And Processing Experimental Research On Microstructure Surface Of High-speed Train With Drag Reduction Function

The railway plays an important role in transportation.Therefore,to improve the speed of the train is significant.However,the study of train appearances has gradually entered a bottleneck.The micro-structured functional surface has many good characteristics.When it is applied to the mechanical structure,it can improve the hydrodynamic performance of the surface and reduce the resistance.Based on this,we make design analysis and processing experimental research for the surface of high-speed trains with drag reduction function.In order to determine the optimal microstructure and experimental model,we use the computational fluid mechanics as theoretical basis,and combine with the opening grid preprocessing software and fluency simulation analysis software.The geometric model establishment and simulation analysis of the plane and the micro structured plane are then performed.Based on the simulation results,the optimal microstructure is selected.The aerodynamic analysis of the head of the high-speed train is conducted to find the aerodynamic sensitive area.A specific analysis model is proposed to study the optimal size of the V-groove using the control variable method.In order to obtain the V-groove surface with good surface quality,based on the existing laboratory machine tools,orthogonal test method and range analysis method,the V-groove micro-milling process parameters optimization experiment is designed.Detecting the surface quality of the processed surface to obtain the effect of different processing parameters on the surface processing quality of the V-shaped groove,the optimal cutting parameters are chosen to obtain the best V-groove.A comparative experiment on the smooth surface and the microstructure surface is conducted to verify the actual drag reduction effect.Based on the subsonic wind tunnel test rig(Engine Gas Dynamics Research Center,Harbin Institute of Technology),the Pitot tube and other high-precision measurement equipment,characteristics of the fluid at the outlet and entrance of the test are measured,and then the changing trends of different airflow parameters are obtained.Comparing the smooth surface with the V-groove surface,the resistance of the V-groove is smaller and the drag reduction effect is better.In conclusion,the V-groove structure may facilitate the drag reduction of high-speed train.