# Precursors to splashing of liquid droplets on a solid surface

## Overview

Authors: Shreyas Mandre, Madhav Mani & Michael P. Brenner

Source: Physical Review Letters, Vol.102, 134502, (2009)

Soft Matter key words: droplets, splashing, capillary waves, surface tension, pressure, thin film

## Abstract

In this publication authors develop a theoretical model for a droplet splashing against a solid wall, which they confirm by running computer simulations. Contrary to popular belief, they stipulate that high pressure of the air film trapped between the wall and the liquid drop actually prevents the drop from contacting the wall. Instead, the droplet spreads on the thin air film and emits capillary waves.

## Soft Matter Snippet

Fig.1 : Shreyas Mandre, Madhav Mani & Michael P. Brenner
Fig.2 : Shreyas Mandre, Madhav Mani & Michael P. Brenner

It is interesting to take a closer look at the set of equations chosen to describe this fluid dynamics problem. The gas films deforms according to the differential equation:

$12 \mu (\rho h)_l = (\rho h^3 p_x)_x$

Here $\mu$ is the gas viscosity, $\rho_l$ is the liquid density and $\rho_x$ is the gas density. Accordingly, $p_x$ is the gas pressure and $p_l$ the liquid pressure.