Paper Number
PL3 

Session
Plenary Lectures

Title
Electrified droplets: Instabilities, interactions, and rheology

Presentation Date and Time
October 13, 2021 (Wednesday) 8:30

Track / Room
Plenary Lectures / Ballroom 5-6-7

Authors (Click on name to view author profile)

1. Vlahovska, Petia M. (Northwestern University, Engineering Sciences and Applied Mathematics)

Author and Affiliation Lines (in printed abstract book)
Petia M. Vlahovska
Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208

Speaker / Presenter 
Vlahovska, Petia M.

Keywords
active materials; colloids; suspensions

Text of Abstract
The interaction of fluids and electric fields is at the heart of natural phenomena such as the disintegration of raindrops in thunderstorms and many practical applications such as electrosprays, ink-jet printing, microfluidics, and crude oil demulsification. Many of these processes involve droplets and there has been a long-standing interest in understanding drop electrohydrodynamics. In this talk I will overview some intriguing phenomena involving viscous drops: symmetry-breaking instabilities in strong fields due to the Quincke rotation effect (droplet pancake-like flipping, formation of a belt of vortices around the drop equator), streaming from the drop equator that creates visually striking ``Saturn-rings" around the drop, non-axisymmetric “kiss-and-run” interactions of a drop pair, and a negative electrorheological effect in emulsions. These complex behaviors arise from nonlinear dynamics in the Stokes flow regime that is yet to be fully understood.