Verification of PLAID Phase Change Algorithm Applied to Direct Numerical Simulation of Condensation Phenomena

A new algorithm developed for flexible, regime-independent phase change simulations has been developed and is undergoing verification. The Parallel Lattice Algorithm for Interphase Dynamics (PLAID) is designed to resolve spatial variations in phase change rate within the Level-Set interface tracking framework. It has been implemented in the massively parallel multiphase CFD flow solver PHASTA and represents a major advance in versatility over the previous phase change algorithm implementation. The previous phase change algorithm was a Lagrangian based approach that was intended for application to bubbly flows. As such, each vapor mass was treated independently and assumed to be spherical. PLAID makes no assumptions on the shape of the interface and offers a purely Eulerian approach to phase change phenomena. It works by overlaying a coarse cartesian lattice on the computational mesh and computes the net heat flux toward the interface independently within each lattice cell. PLAID has previously undergone verification for simple boiling, however robustness demands that verification for the reverse process is completed as well. In this work the application of PLAID to simple condensation cases with known solutions is presented, including the Stefan and Scriven problems for interphase transfer. Additionally, the effects of mesh and lattice refinement on the results are investigated.