Isothermal Multiphase Flow using a Multi-domain Lattice Boltzmann Method

In an effort to increase the useful property range of Lattice Boltzmann multiphase flow simulations, a multiple fluid domain approach has been developed. Specifically, the purpose of this approach is to allow higher density and viscosity ratios across fluid interfaces with minimal spurious currents and instability. The multiple domains are coupled through interpolated boundary conditions. A level-set method on a collocated grid is used to track the interface location, which provides the necessary information for implementing moving, interpolated boundary conditions on each of the domains. The multi-domain Lattice Boltzmann method coupled with a level-set method allows for a sharp interface to apply the interfacial conditions and surface tension forces, while implicitly handling topological changes. To demonstrate the capabilities of this method, a test case of buoyancy driven bubble train flow will be presented with several increasing density and viscosity ratios.