Parallel LBM to Simulate Gravity Driven Bubbly and Slug Flows

Multi phase and multi component flows are ubiquitous in nature as well as in many man-made processes. Multi-phase flows typically manifest a wide variety of geometrical patterns (or flow regimes) of associated phases depending on several system conditions. These patterns include, but are not limited to, bubbly, slug, churn or annular flows. In the case of boiling this may lead to Departure from Nucleate Boiling (DNB). Simulation and identification of these flow regimes via numerical simulations is not a trivial task partly due to the need for extensive interface tracking. Consequently, analysis of multi-phase flow is still largely based on empirical formulas. In comparison with continuum approaches based on fluids equations for different phases, use of Lattice Boltzmann Method (LBM) may prove highly advantageous because of its inherent ability to incorporate particle interactions to yield phase segregation. Both, single and multi-component multiphase fluids can be simulated using this approach [16]. We are using LBM to address multiphase flow problems specific to nuclear engineering such as the simulation and prediction of Critical Heat Flux (CHF). Some preliminary results to simulate multi-phase flows without heat transfer are presented here.