NUMERICAL SIMULATION OF TRAJECTORY OF SPRAY GENERATED BY ELECTROSTATIC ATOMIZERS

Abstract

Atomization is the process of disintegrating a bulk fluid volume into fine droplets. The collection of such fine, minute droplets that comes out of the nozzle exit is termed as Spray. Atomization of fluids take place in two steps - primary atomization, where the pressure energy of the fluid is converted into kinetic energy, and secondary atomization, where the atomized fluid undergoes further break up into smaller droplets. In many applications like fuel injection, painting, inkjet printing, thermal coating and preparation of pharmaceuticals, the basic task is to break the fluid volume into sprays i.e., atomization. There are various types of atomizers like ultrasonic, centrifugal, air assisted, electrostatic etc. The present study focuses on comparing the spray tracks of electrically conductive and nonconductive liquids using an electrostatic atomizer, where the fluid flows through an electric field generated due to a voltage difference between electrode and the exit. The methodology includes designing of the electrostatic atomizer in Fusion 360 followed by numerical simulation. The simulation was carried out in two parts. The particle track comparison was carried out for water and diesel in the presence and absence of an electric field. Particle sizes and spray patterns showed significant variations in all cases. Diesel being a non-conductive fluid, had negligible variations in the presence and absence of electric field. But water due to the induced charges, produced a jet form of a spray with comparatively low mean particle size. Future studies can focus on conducting experimental analysis and compare it with the numerical results.