A modified pseudopotential for a lattice Boltzmann simulation of bubbly flow

Abstract

The pseudopotential in Shan and Chen-type multiphase models was investigated and modified based on a virial equation of state with newly proposed parameters. This modified pseudopotential was used in a lattice Boltzmann model and shown to be suitable for simulating sufficiently large gas–liquid density ratios with good numerical stability and only small spurious velocities. The spurious velocity was reduced by reducing the pseudo-sound speed by the use of suitable parameters. The multicomponent multiphase model based on this modified pseudopotential can be used in bubbly flow simulations. Bubble rise behavior was simulated using a 3D multicomponent and multiphase model with a high density ratio. The predicted terminal velocity and drag coefficient of a single bubble agreed well with those calculated from empirical correlations. The drag coefficient of bubbles in the homogenous regime decreased with increased gas holdup. A new relationship between the bubble drag coefficient and gas holdup in the homogenous regime was proposed.