Dynamics Characteristics of Viscous Oil Droplets Impacting on Inclined Wetted Walls

Microlubrication technology significantly improves lubrication performance and heat dissipation during metal cutting by spraying atomized oil droplets around the surface of the workpiece to form a uniform lubrication film. Therefore, it is of great significance to thoroughly investigate the effects of the viscosity characteristics of oil droplets and the inclination angle of the wall on the dynamic behavior of oil droplets impacting on the inclined wall. The dynamic process of viscous oil droplets impacting the inclined wetted wall was observed and analyzed through high-speed camera experiments, with the aim of investigating the effects of droplet viscosity, impact velocity, and wall inclination on the morphological characteristics and distribution pattern of the oil droplets. The results show that the morphological characteristics of oil droplets are affected by the coupling of droplet viscosity, wall inclination, impact velocity, etc. and that deposition spreading, jet slipping, and jet fracture will occur. The increased viscosity inhibits the generation of jet fracture phenomena, causing the critical angle at which jet fracture occurs to increase, leading to a shift in the critical kinematic morphology critical point. Increasing the Weber number and the inclination of the wall will be more favorable for the occurrence of the jet fracture phenomenon. The ratio of deposition spreading at low inclination increases with an increasing viscosity of oil droplets in a certain range, and the spreading characteristics of oil droplets with different viscosities are more significantly affected by the angle of the wall. The fracture time of the jet decreases with the increase of impact velocity, and the volume of the droplet increases with the increase of wall inclination.