Convection in multiphase fluid flows using lattice Boltzmann methods

Biferale, L., Perlekar, P., Sbragaglia, M. & Toschi, F. (2012). Convection in multiphase fluid flows using lattice Boltzmann methods. Physical Review Letters, 108(10):104502


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\sim 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.