Object-oriented software development applied to adaptive resolution control in two-fluid models

Abstract

The accuracy of two-phase flow simulations is mainly determined by the mathematical formulations and resolution of the computational mesh used in the numerical model. Selective mesh refinement improves the accuracy of results while maintaining low resource requirements. This study introduces arbitrees, a new recursive grid design that allows hierarchical refinement and coarsening to be applied on uniform and arbitrary grids. An object-oriented simulation framework was developed that allows the mathematical equations to be written directly in the code, providing direct control over the behaviour of the flow model. Two-fluid models based on the volume of fluid method are implemented and coupled to the arbitree grid to investigate adaptive refinement in two-fluid simulations. Test cases for shape advection in oblique, rotating and shear flow were used to validate the interface tracking capabilities of the adaptive system. The adaptive two-fluid methodology was tested by modelling the collapse of a liquid column. In all cases, the predicted results exhibited encouraging agreement with analytical solutions or experimental measurements.