Coalescence in low-viscosity liquids

TL;DR

This paper introduces an electrical measurement technique to study the early-stage coalescence of low-viscosity droplets, revealing a new asymptotic regime that challenges existing theories.

Contribution

It presents a novel electrical method for observing droplet coalescence dynamics and identifies a previously unrecognized asymptotic behavior.

Findings

Discovered a new asymptotic regime in droplet coalescence.

Measured growth dynamics of the connecting bridge.

Results support a model with slightly deformed interfaces.

Abstract

The expected universal dynamics associated with the initial stage of droplet coalescence are difficult to study visually due to the rapid motion of the liquid and the awkward viewing geometry. Here we employ an electrical method to study the coalescence of two inviscid droplets at early times. We measure the growth dynamics of the bridge connecting the two droplets and observe a new asymptotic regime inconsistent with previous theoretical predictions. The measurements are consistent with a model in which the two liquids coalesce with a slightly deformed interface.