CFD study of two-phase equilibrium systems using different models

Computational Fluid Dynamics (CFD) is becoming more and more common for both Research \& Development and Industrial fields. It can provide accurate data with relative low costs and quick turn-around designs, without needing a physical prototype to be produced. Due to the simplifications done in most CFD codes, accuracy can be compromised if the setup is not done appropriately, which is why it is often mandatory to perform a validation case. This need for validation can pose significant limitations when the research is too far off from a preliminary design and there is no experimental data to check the simulation against. This paper suggests the implementation of a simple but reliable User-Defined model for the inter-phase mass and energy exchange of a two-phase system. The model is based entirely on the conservation of energy and is designed for systems where phase change is the primary objective and is significantly faster than other processes. It ignores all kinetics and inertial terms, aiming to provide a simple, reliable and easy-to-understand representation of a much more complex phenomenon.