Simulation And Analysis Of Active Chip Eliminate Process Using Open Abrasive Belt For Rail Grinding

During the rail service,the rail tread will present various forms of disease,which will seriously affect the stability and safety of the train operation.Rail grinding is an effective mean to eliminate rail disease.Rail corrugation is a common disease in high-speed railway rails,which directly leads to the vertical acceleration of high-speed trains exceeding the standard during operation.The current grinding wheel grinding is difficult to effectively remove the wave grinding,and when the open sanding belt is used for the rail grinding,the grinding speed and the working efficiency can be greatly improved,and the pressing plate contact parts of the profile rail surface can effectively remove the rail corrugation.However,a large amount of grinding chips generated during the grinding operation will retain the occluded abrasive belt,thereby reducing the abrasive belt grinding performance and deteriorating material removal conditions.Therefore,this paper intends to design the contact part profile features and use pneumatic chip removal to solve the problem of grinding chip blockage,and carry out related numerical simulation research.Based on the theory of fluid mechanics,this paper uses numerical simulation and simulation research methods to extract the surface morphology of the abrasive belt,study the characteristics of the abrasive grain,design the surface structure of the pressure plate,and establish the model of the debris flow field.Using FLUENT to simulate the flow field,the pressure and velocity distribution of the flow field,the discrete phase particle trajectory and the chip removal rate are obtained,and the coupling simulation is carried out by FLUENT-EDEM to verify the feasibility of the pneumatic chip removal and the profile characteristics of the pressure plate.And carry out related research on the grinding plate type abrasive belt grinding experiment,the main work is as follows:(1)Sand belt shape acquisition and airflow field model establishment.The actual shape of the surface of the abrasive belt was measured,and the space of the chip surface on the surface of the abrasive belt was calculated,and coMPared with the grinding amount of the abrasive belt under the open working condition.Based on a certain amount of grinding,the reasonable value range of the groove width of the plate is determined,and the airflow field model of the chip removal area under the wear and wear condition of the belt is established,which provides the flow field calculation domain for flow field simulation analysis and FLUENT-EDEM coupling.(2)Analysis and modeling of grinding chips characteristics.Combined with the grinding theory,the shape and related geometrical characteristics of the abrasive particles are analyzed.Under the open working condition,the abrasive chips generated by the abrasive belt grinding are collected,and the numerical model for characterizing the shape and size of the grinding chips is proposed.A calculation model for typical grinding chip is provided for flow field simulation analysis in the contact zone of the rail belt.(3)Simulation and analysis of active grinding chips removal process.FLUENT was used to simulate the internal airflow field change of the blowing nozzle,and the best internal structure was selected.The single factor method was used to select the two non-structural parameters(discharge pressure and blowing distance)which have the greatest influence on the blowing effect,and the FLUENT simulation calculation was carried out.The effect of different non-structural parameters on active chip removal when the belt is in different states.The FLUENT-EDEM coupling method is used to accurately reduce the effect of particles on the flow field and the collision of particles with particles,particles and walls.The simulation of the chip removal area is carried out again to verify the rationality of the flow field simulation,as well as the pneumatic chip removal and pressure.The feasibility of slotting the surface of the grinding plate.(4)Experimental verification of abrasive belt grinding under blowing.Using the laboratory's rail abrasive belt grinding test bench,to explore the effect of airflow on the grinding chip removal under open conditions,quantitatively analyze the distribution of grinding chips on the surface of the abrasive belt after grinding,verify the feasibility of active chip removal and flow field simulation.correctness.