Numerically Robust Six-Equation Two-Phase Flow Model for Stationary and Moving Systems in Modelica

Abstract

We present a physics based Modelica finite volume flow model that separately balances vapour and liquid phase. By using extensive state variables and a special mass flow regularisation, the model can cope with the possible vanishing or emerging of a phase in a numerically robust way. Although at prototype stage, the model already exhibits all required capabilities. These are demonstrated in feature testers and in a model of a natural convection driven cooling cycle operating under external acceleration forces.