The evaporation and condensation model with interface tracking

Abstract

Interface tracking simulation (ITS) is one of the promising approaches to describe heat transfer of boiling phenomena and their underlying mechanisms. Better understanding and modeling of this process will benefit various engineering systems relying on two-phase heat transfer. The presented research implements, verifies and validates the modeling capability of the evaporation process using a massively parallel unstructured grid flow solver, PHASTA. The verification of the evaporation and condensation model has been performed by comparing the bubble growth rate with analytical solutions. Both pool boiling and flow boiling simulations are performed using this ITS evaporation and condensation model. The bubble nucleation frequency in pool boiling simulation is validated against experimentally-based correlations. The bubble evolution and growth rate are compared with experimental data to validate the model performance under flow boiling condition. The authors propose an innovative ITS based-boiling model which can conduct boiling simulation with 3D unstructured computational mesh. This capability will serve as one of the most important building blocks for high resolution boiling simulation in realistic engineering geometries being developed under the PHASTA simulation framework. Compared to the structured-grid-based solvers, which are challenging to apply to complex engineering geometries, this boiling model implementation is capable of conducting high-resolution boiling simulations in engineering geometries and resolving the detailed hydrodynamics and thermal information for quantities of interest at/around the interface. This approach may help fulfill the numerical data gap between the local physical phenomena and the engineering scale ITS applications in the future.