Experimental Study And Atomization Mechanism On Vegetable Oil Based Electrostatic Atomization And MQL

Green and sustainable development is the mainstream trend in today’s manufacturing industry.In order to solve the problems of high cost,waste of resources and environmental pollution in traditional manufacturing industry,"Made in China 2025" requires cleaner manufacturing in manufacturing industry for sustainable manufacturing,"13th Five-Year plan" and "New and Old Kinetic Energy Conversion in Shandong Province" both put forward the concept of technological innovation,green and low carbon.Grinding is an indispensable way of machining,and minimum quantity lubrication(MQL)grinding is an energy-saving and environment-friendly green grinding method.However,the breaking mechanism of liquid jet under high pressure is complex,so it is impossible to realize the active control of droplet distribution.Based on the above problems,the atomization mechanism and lubrication performance of vegetable oil-based electrostatic atomization minimum quantity lubrication(EMQL)grinding are studied.the electrostatic field distribution and corona discharge model of needle-plate electrode and the multi-physical field coupled atomization kinetic model are established,and the corona discharge mechanism,liquid charging mechanism and electrostatic atomization characteristics are systematically studied and analyzed.Finally,the atomization characteristics and lubrication performance of EMQL grinding are studied experimentally with the atomization cone angle,droplet charge and droplet size distribution as evaluation parameters of atomization performance,and surface roughness and surface morphology as evaluation parameters of lubrication performance.The specific research work is as follows:(1)The model of charged liquid atomization mechanism is established,and three different ways of liquid charging are studied.The corona discharge condition of needle-plate corona discharge is quantitatively analyzed,and the charge of droplets under corona discharge is also analyzed.The critical Weber number and critical charge for breakup of charged droplets are obtained,and a dynamic model of charged droplets in the flow field and electric field is established.(2)The electrostatic field distribution and corona discharge model of needle-plate electrode are established.The distribution law of electric potential and electric field intensity under different voltage is analyzed,and a detailed analysis of the high field strength area near the needle pole is made.The generation,movement and dissipation of charged particles in corona discharge are studied.The ionic wind induced by corona discharge is further studied,and the distribution of air flow field is obtained.(3)A multi physical field coupled atomization dynamic model for electrostatic atomization and MQL grinding is established,the charging and breaking mechanism of liquid is analyzed,and the change rule of droplet formation velocity and charge density are obtained.The coupling airflow field model of grinding wheel and nozzle is established,and the position of the nozzle is determined according to simulation results.The electrostatic atomization discrete model is established,and the variation law of atomization cone angle,average droplet size,cumulative droplet size distribution and probability density function based on droplet number are analyzed.(4)The effects of different voltages on electrostatic atomization are studied,the atomization cone angle,charge to mass ratio and droplet size distribution are analyzed and compared with the simulation results,and compared with the simulation results,the reasons for the error in the experiment and simulation and the influence of the voltage on the atomization performance of the lubricating fluid are analyzed.(5)Grinding experiments of nickel-based alloys under dry,flood,MQL and EMQL(voltage-20 to-40 kV)are carried out using vegetable oil-based synthetic esters.Through the comprehensive analysis of surface roughness Ra,RSm and surface topography of workpiece,it is concluded that the lubrication performance of electrostatic atomization MQL grinding,and the optimal workpiece surface quality can be obtained the best optimal electric field parameter.