Conference article

A model and solution method for phase transition in compressed lique?ed gases is presented. The model is a two-phase 6-equation model with a common ?ow velocity for the two phases. The numerical method for solving the model is based on the 2. order shock capturing MUSCL-scheme with a HLLC Riemann solver. The van der Waal cubic equation of state is used for closing the set of equations. The phase transition model is based on thermodynamic and mechanical relaxation between the phases. The goal of the work is to present a numerical model capable of resolving the two-phase ?ow situation in the depressurization of a vessel or pipe containing lique?ed CO2. Simulation of expansion and phase transition in pressurized lique?ed CO2 is presented and compared with experimental data. The simulations are with a one dimensional geometry and the experiments are performed in a narrow tube. Wall effects in the experiments are not captured in the simulations. The wave structure seen in the experiments is reproduced by the simulation although not quantitatively. The simulations show that the ?uid is in the metastable region before it undergoes a phase transition. The level of expansion of the metastable liquid shown in the in the simulations is not seen in the experiments.

phase transition, lique?ed gas, BLEVE, van der Waal, MUSCL