Character and Behavior of Mist Generated by Application of Cutting Fluid to a Rotating Cylindrical Workpiece, Part 1: Model Development

Abstract

Increasing attention is being devoted to the airborne emissions resulting from a variety of manufacturing processes because of health, safety, and environmental concerns. In this two-part paper, a model is presented for the amount of cutting fluid mist produced by the interaction of the fluid with the rotating cylindrical workpiece during a turning operation. This model is based on relationships that describe cutting fluid atomization, droplet settling, and droplet evaporation. Experiments are performed to validate the model. In Part 1 of the paper, the emphasis is on model development. In the model, thin film theory is used to determine the maximum fluid load that can be supported by a rotating cylindrical workpiece; rotating disk atomization theory is applied to the turning process to predict the mean size of the droplets generated by atomization; and expressions for both the evaporation and settling behavior are established. Droplet size distribution and mass concentration predictions are used to characterize the fluid mist. Model predictions indicate that the droplet mean diameter is affected by both fluid properties and operating conditions, with cutting speed having the most significant affect. Model predictions and experimental results show that the number distribution of droplets within the control volume is dominated by small droplets because of the settling and evaporation phenomena. In Part 2 of the paper, the cutting fluid mist behavior model is validated using the results obtained from a series of experiments.

Effects of Speeds, Materials, and Tool Rake Angles on Metallic Particle Emission During Orthogonal Cutting

“…Solid aerosols are generated from part materials during dry and wet machining, while liquid aerosols are produced when cutting fluids are used (Ref [3][4][5]. The primary mechanisms responsible for wet aerosol production include fluid impact on the workpiece and evaporation (Ref [6][7][8][9][10][11].…”

Experimental Study on Generation Mechanism and Influencing Factors of Metal Machining Fluid Oil Mist Microparticles

“…However, not all influencing factors have decisive effect on the generation of cutting fluid oil mist. Practically, pulverization mechanism and evaporation mechanism are two common generation mechanism of oil mist during metal cutting [2][3][4][5]. The pulverization mechanism of metal cutting fluid is equal to the conversion of mechanical energy into droplet surface energy.…”

Development of an Imaging System and Its Application in the Study of Cutting Fluid Atomization in a Turning Process

“…Depending on process parameters, the atomization mechanism associated with the rims can adopt one of the three modes identified by other researchers: drop formation mode, ligament formation mode, and film formation mode. As part of the development of a model for the atomization process Yue et al (1996Yue et al ( , 2000aYue et al ( , 2004) established a relationship for the axial spacing between the rims that are formed in the atomization process and the maximum fluid flux that a cylindrical workpiece can contain before drainage occurs.…”

“…The axial position at which the flow stops and rims form depends on the workpiece rotating speed, stream velocity, and the fluid properties. Yue et al (1996Yue et al ( , 2000aYue et al ( , 2004 established the following expression for the fluid film width, or alternatively, the spacing between rims: where Fr ¼ U j 2 =(gR) is the Froude number, e ¼ 0.5R e 0.5 (r j =R) 2 , and R e ¼ U j R j =v is the Reynolds number of the fluid stream.…”

“…As a prelude to discussing the imaging system and atomization experiments, a brief overview of the cutting fluid atomization process is provided, and some observed behaviors are compared with the theoretical predictions of Yue et al (1996Yue et al ( , 2000aYue et al ( , 2004. The particle imaging system is then described, and the experimental plan to examine the atomization process is presented.…”