Bachelor's Thesis

As part of my 8th Semester Bachelor's Thesis, I worked under Professor Absar Lakdawala (Associate Professor), Mechanical Engineering on the phenomenon of Electro coalescence.

Electro-coalescence refers to the phenomena of the liquid-liquid interface coalescing under the influence of electrostatic field. Depending on the various parameter conditions, the impact of a drop on a liquid-liquid interface might result in Electrohydrodynamic Complete Coalescence (EHCC), Electrohydrodynamic Partial Coalescence (EHPC), or Electrohydrodynamic Jetting (EHJ). When a drop approaches a liquid-liquid interface, it will rest there for a set amount of time, which is known as the drop’s rest-time at the interface. The thin liquid film that is caught between the drop and the liquid-liquid interface which ensures stability will drain to its critical thickness and at that point in time, any external perturbation causes the fluid film to rupture, which causes the drop interface coalescence. Here, the purpose of applied electrical field is to provide this external perturbation thus promoting contact between the drop-interface, resulting in coalescence. The coalescence of a drop at an interface may produce a secondary drop, depending on the viscosity ratio and many other parameters of the liquids thus leading to a cascade phenomenon where each impact leaves behind a smaller secondary droplet. This phenomenon is known as partial drop-interface electro coalescence. The interactions between the drops and the externally applied electrostatic field are thought to result in drop charging, agglomeration, and eventually coalescence. Application of the electro-coalescence is for separation of emulsions, such as an aqueous phase and an oil phase both immiscible liquids, thoroughly dispersed in one another which arises in the chemical processing and industrial sectors.

Checkout my Bachelor's Thesis.

These animations were made from the simulations of phenomenon done using OpenFOAM by modifying code to include the effects of Electric Field on Paraview.