Publications de Giacomo Gallino

The Hydrodynamics of a Micro-Rocket Propelled by a Deformable Bubble

François Gallaire, Giacomo Gallino, Lailai Zhu

We perform simulations to study the hydrodynamics of a conical-shaped swimming micro-robot that ejects catalytically produced bubbles from its inside. We underline the nontrivial dependency of the swimming velocity on the bubble deformability and on the ge ...

2019

Edge states control droplet breakup in subcritical extensional flows

François Gallaire, Giacomo Gallino, Tobias Schneider

A fluid droplet suspended in an extensional flow of moderate intensity may break into pieces, depending on the amplitude of the initial droplet deformation. In subcritical uniaxial extensional flow the nonbreaking base state is linearly stable, implying th ...

2018

Viscous growth and rebound of a bubble near a rigid surface

François Gallaire, Giacomo Gallino

Motivated by the dynamics of microbubbles near catalytic surfaces in bubble-powered microrockets, we consider theoretically the growth of a free spherical bubble near a flat no-slip surface in a Stokes flow. The flow at the bubble surface is characterised ...

Cambridge University Press2018

When droplets deform, break up and propel microswimmers

Giacomo Gallino

This thesis investigates the motion and breakup of droplets in low-Reynolds-number flows, focusing on two aspects. In the first part, we study the breakup of droplets in subcritical flow conditions, when there exists a linearly stable solution for the drop ...

EPFL2018

Physics of Bubble-Propelled Microrockets

François Gallaire, Giacomo Gallino

A popular method to induce synthetic propulsion at the microscale is to use the forces created by surface-produced gas bubbles inside the asymmetric body of a catalytic swimmer (referred to in the literature as microrocket). Gas bubbles nucleate and grow w ...

2018

The stability of a rising droplet: an inertialess non-modal growth mechanism

François Gallaire, Giacomo Gallino, Lailai Zhu

Prior modal stability analysis (Kojima et al., Phys. Fluids, vol. 27, 1984, pp. 19-32) predicted that a rising or sedimenting droplet in a viscous fluid is stable in the presence of surface tension no matter how small, in contrast to experimental and numer ...

Cambridge University Press2016