Mechanism and Experimental Study on Electrostatic Atomization Using Needle-Shaped Electrodes

Abstract

The conventional pneumatic Minimum Quantity Lubrication (MQL), when not properly designed, may have poor atomization and insufficient wetting performance, resulting in higher oil mist concentration and poor film formation ability in the cutting zone. The intervention of an external electric field can change the atomization mechanism of microdroplets and enhance the lubrication and cooling capability of MQL. However, the mechanism of the effect of jet parameters on the atomization performance of Electrostatic Minimum Quantity Lubrication (EMQL) under the synergistic effect of multiple fields has not been fully analyzed. In this paper, based on the designed needle electrode charging nozzle, the atomization medium charging and atomization mechanisms are investigated, and a mathematical model of the volume average diameter of droplets (VAD) is established. Based on multi-parameter atomization experiments, the electrode conical jet atomization model is validated and the mechanism of the influence of jet parameters on the atomization characteristics is analyzed. The results show that the VAD is negatively correlated with air pressure and electrical. The atomization performance of the droplets was improved under the applied voltage condition, which was manifested by the obvious refinement of the VAD, with a maximum reduction of 34.67%, a maximum reduction of 20% in the droplet group size distribution span (R.S.), and a different degree of reduction in the percentage concentration of fine particulate matter. In addition, the model fitted well with the experimental values, with an overall error of about 10%.