(Dr. Steven Liang, advisor)
"Cutting Fluid Aerosol from Splash in Turning: Analysis for Environmentally Conscious Machining"
The generation of airborne particulate from the use of cutting fluid poses a potential threat to the health of human operators on manufacturing shop floors. The primary mechanisms through which cutting fluid atomizes into the form of liquid aerosol are the splash upon impingement on a solid workpiece, the spin-off away from a rotating workpiece or tool, and the evaporation at the presence of high cutting temperature.
A study to present a quantitative model to describe the aerosol concentration and size distribution resulting from the splash atomization of cutting fluids in a lathe turning operation is performed. In this study, the main parameters that govern the aerosol formation are the workpiece diameter, nozzle height, cutting fluid properties, and cutting fluid flow rate. The first part of this model determines the fraction of splashed mass to total mass flow rate of `cutting fluid based on the calibration of the splash parameter. The second part of the model determines the statistical variation of the liquid droplet size due to unaccounted disturbances. The aerosol concentration is then given in terms of the product of the fraction of splashed cutting fluids and the fraction of total droplet volume of a specified diameter. The validity of the model is experimentally established using light-scattering aerosol measurement carried out on an actual horizontal lathe with various jet height, part diameters, and fluid flow rates.
The result of this study can be used to estimate the amount of aerosol expected of a machining process, and to provide a quantitative basis for process optimization, fluid planning, and machine design in achieving a given environmental standard.