Simulation And Experimental Research On The Grinding Fluid Flow Field Of The Wheel With Ordered Microgrooves

Grinding is often used for precision and ultra-precision machining of key parts.Due to the influence of gas barrier layer on traditional grinding wheel,it is difficult for coolant to enter the grinding zone for effective lubrication and cooling.Therefore,how to improve the structure of grinding wheel face to improve the lubrication and cooling performance has always been the focus of research in grinding field.Based on this,our research group proposed an electroplated grinding wheel with orderly-micro-grooves.In this paper,the simulation research on the flow field and gas-liquid two-phase flow in.the grinding zone was carried out,and the effective flow experiment of coolant was collected,revealing that the lubrication and cooling mechanism of electroplated grinding wheel with orderly-micro-grooves.The main research contents are as follows:(1)The CFD method was used to simulate the airflow field in the grinding zone of ordered micro-grooves grinding wheel,and the influence of rotational speed and wedge clearance on the air barrier layer around grinding wheel was studied.The simulation results show that:when the grinding wheel with orderly-micro-grooves rotates,an air barrier layer will be generated around it.And a return flow will be formed at the entrance of the wedge gap between the grinding wheel and the workpiece,which will hinder the effective supply of coolant to the grinding zone.With the micro-grooves rapid cutting in and out,the gas barrier layer around the grinding zone will be disturbed.As a large number of micro-grooves are distributed on the outer circumferent surface,thus reducing the pressure of the gas barrier layer,which is conducive to the smooth entry of coolant into the grinding zone.With the increase of the rotational speed of the grinding wheel,the air pressure in the grinding zone increases gradually.With the decrease of the minimum clearance between grinding wheel and workpiece,the peak value of air pressure in grinding zone increases sharply,but the distribution law of air velocity and air pressure is basically unchanged in horizontal direction.(2)The mathematical model of coolant utilization rate was established,and the simulation of gas-liquid two-phase flow in grinding wheel with orderly-micro-grooves was carried out.The results show that:when the grinding wheel rotates,the micro-grooves can accommodate and transport more coolant.And reduce the fluid dynamic pressure between the grinding wheel and the workpiece,thus the coolant can easily enter the grinding zone for lubrication and cooling.Within a certain value range,the effective flow rate increases with the increase of rotational speed and coolant jet velocity,and the coolant utilization rate is between 5%and 20%.When the incidence Angle is 15°,the effective flow of coolant is greater than that of horizontal incidence.The effective flow of coolant reduce sharply with the decrease of the minimum clearance,and decreases with the increase of the micro-groove width.(3)An ordered micro-grooves electroplated wheel with groove width of 0.1mm was prepared,and the effective flow rate of coolant was tested.The results show that the effective flow rate of the wheel with orderly-micro-grooves is significantly increased,reaching 1.42 times of that of the traditional wheel.That indicates the large number of micro-grooves distributed on the outer circumference of the wheel can improve the lubrication and cooling performance of the grinding zone.