Application of Computational Fluid Dynamics in MQL (Minimum Quantity Lubrication) Machining

This paper presents an overview of simulation studies done on minimum quantity lubrication (MQL) machining. Minimum quantity lubrication (MQL) is a method where cutting fluid is supplied at very low rate forming ultra-fine droplets that with the help of pressurized air strikes the work piece with high velocity through nozzle without any waste being left for disposal. Minimum quantity lubrication’s (MQL) performance is dependent on the spray generated by the MQL system. The spray quality is defined by number of droplets, sauter mean diameter, pressure of droplets and velocity of droplets and depends on factors such as coolant flow rate, flow rate of air, pressure of compressed air, nozzle orientation and nozzle geometry. Further it is concluded from literature review that the increase in air pressure and increase in flow rate of oil produced the droplets that can penetrate the tool-chip interface easily to provide effective lubrication with nozzle placed at some angle to the tool axis. Better lubrication increases tool life, improves surface finish, reduced cutting temperature and cutting forces.