Title: Splitting methods for relaxation two-phase flow models

Authors: H. Lund; P. Aursand

Addresses: Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway ' SINTEF Energy Research, Sem Sælands vei 11, NO-7465 Trondheim, Norway

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 CO2 pipeline depressurisation case.

Keywords: hyperbolic conservation laws; relaxation; splitting methods; phase transfer; exponential integrator; two-phase flow; statistical rate theory; pipeline flow; evaporation modelling; condensation modelling; hyperbolic equation; fluid mechanics; multi-stage finite volume; pipeline depressurisation.

DOI: 10.1504/IJMATEI.2013.054391

International Journal of Materials Engineering Innovation, 2013 Vol.4 No.2, pp.117 - 131

Published online: 19 Jul 2014 *

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