Compressibility effects in droplets impacted by a laser pulse

The impact of a laser pulse onto a liquid droplet can induce a strong deformation and propulsion of the droplet. We can model this laser impact as a one-sided pressure pulse applied on the liquid-vapor interface of the droplet. We aim to understand the fluid dynamic response of the droplet in a regime where the duration of the pressure pulse is very short, i.e.\ of the order of the timescale on which pressure waves travel through the droplet. We use Lattice-Boltzmann simulations to study the effects of pressure-wave propagation on a number of phenomena: energy partition, wave reflection on interfaces, droplet deformation and cavitation. We complement the simulation by a perturbation analysis of the Navier-Stokes equations in the weakly compressible regime. In the weakly compressible regime, we observe good agreement between the Lattice-Boltzmann simulations and this analytical model.