Splitting methods for relaxation two-phase flow models

Abstract

A model for two-phase pipeline flow is presented, with evaporation and condensation modelled using a relaxation source term based on statistical rate theory. The model is solved numerically using a Godunov splitting scheme, making it possible to solve the hyperbolic fluid-mechanic equation system and the relaxation term separately. The hyperbolic equation system is solved using the multi-stage (MUSTA) finite volume scheme. The stiff relaxation term is solved using two approaches: One based on the Backward Euler method, and one using a time-asymptotic scheme. The results from these two methods are presented and compared for a CO 2 pipeline depressurization case.

An acoustic-convective splitting-based approach for the Kapila two-phase flow model

“…The SG EOS parameters are determined by shock wave Hugoniot curves [33][34][35]. This EOS is often used as a reasonable approximation for both liquids and gases under high pressure conditions [12,13,17,21,36,37]. The EOS allows the determination of the speed of sound of each single phase…”