Heat Transfer Mechanism and Convective Heat Transfer Coefficient Model of Cryogenic Air Minimum Quantity Lubrication Flowing Liquid Film

Abstract

This chapter first studied the heat transfer law of the flowing liquid film between the workpiece interface and grinding wheel with cryogenic air and established the theoretical heat transfer model of flowing liquid film in grinding zone. Further, the convective heat transfer coefficient model of lubricant under different cryogenic air conditions is established and verified by experiment. When the cryogenic air temperature is −10°C, the error between the theoretical and experimental values is 8.5%. Finally, the effects of different cryogenic air minimum quantity lubrication parameters on heat production in grinding zone, liquid film heat transfer, and incoming workpiece heat were analyzed. The results show that the variation trend of the workpiece surface temperature is consistent with the theoretical value. When the grinding depth is 30μm and the cryogenic air temperature is −40 ° C, the error is 7.7%.