Improvement of fully-implicit two-phase pore-network models by employing generalized flux functions with additional throat variables

Martin Schneider; Hanchuan Wu; Maziar Veyskarami; Sorin Pop; Rainer Helmig

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arXiv · 2504.01529

Improvement of fully-implicit two-phase pore-network models by employing generalized flux functions with additional throat variables

Martin Schneider·Hanchuan Wu·Maziar Veyskarami·Sorin Pop·Rainer Helmig

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Abstract

In fully-implicit two-phase pore-network models, developing a well-converged scheme remains a major challenge, primarily due to the discontinuities in the phase conductivities. This paper addresses these numerical issues by proposing a generalized flux function that establishes a continuous flux expression for two-phase flows by introducing an additional throat variable $\Theta$. Two approaches for expressing this additional throat variable are introduced: the first applies regularization strategies, while the second constructs an additional residual constraint equation. It is shown that this approach significantly improves accuracy and ensures the temporal convergence, as demonstrated through various numerical examples.

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Martin Schneider, Hanchuan Wu, Maziar Veyskarami, Sorin Pop, Rainer Helmig. 2025-04-02. Improvement of fully-implicit two-phase pore-network models by employing generalized flux functions with additional throat variables. https://arxiv.org/abs/2504.01529

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