title: Convection in multiphase fluid flows using lattice Boltzmann methods.
abstract: We present high-resolution numerical simulations of convection in multiphase flows (boiling) using a novel algorithm based on a lattice Boltzmann method. We first study the thermodynamical and kinematic properties of the algorithm. Then, we perform a series of 3D numerical simulations changing the mean properties in the phase diagram and compare convection with and without phase coexistence at Rayleigh number Ra∼10(7). We show that in the presence of nucleating bubbles non-Oberbeck-Boussinesq effects develop, the mean temperature profile becomes asymmetric, and heat-transfer and heat-transfer fluctuations are enhanced, at all Ra studied. We also show that small-scale properties of velocity and temperature fields are strongly affected by the presence of the buoyant bubble leading to high non-gaussian profiles in the bulk.
authors.affiliation: Department of Physics and INFN, University of Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Biferale
authors.forename: P
authors.initials: P
authors.lastname: Perlekar
authors.forename: M
authors.initials: M
authors.lastname: Sbragaglia
authors.forename: F
authors.initials: F
authors.lastname: Toschi