Cavitation Mean Expectation Time in a Stretched Lennard-Jones Fluid under Confinement

Description

We investigate the nucleation of cavitation bubbles in a conned Lennard-Jones uid submitted to negative pressures in a cubic enclosure. We perform molecular dynamics (MD) simulations with tunable interatomic potentials that enable to control the wettability of the solid walls by the liquid, i.e its contact angle. For a given temperature and pressure, as the solid is taken more hydrophobic, we put in evidence an increase of the nucleation probability. A Voronoi tessellation method is used to accurately detect the bubble appearance and its nucleation rate as a function of the contact angle. We adapt the Classical Nucleation Theory (CNT) proposed for the heterogeneous case on a at surface to our situation where bubbles may appear at walls, edges or corner of the conned box. We nally calculate a theoretical mean expectation time in these three cases. The ratio of these calculated values over the homogeneous case is computed and compared successfully against MD simulations. Beyond the innite liquid case, this work explore the heterogeneous nucleation of cavitation bubble, not only in the at surface case, but for more complex conning geometries.

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