Implicit-explicit schemes for compressible Cahn-Hilliard-Navier-Stokes equations on staggered grids

Fuente: arXiv
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Main Authors: Martorell, Andreu, Mulet, Pep, Yáñez, Dionisio F.
Format: Preprint
Published: 2025
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author Martorell, Andreu
Mulet, Pep
Yáñez, Dionisio F.
author_facet Martorell, Andreu
Mulet, Pep
Yáñez, Dionisio F.
contents We propose a second-order implicit-explicit (IMEX) time-stepping scheme for the isentropic, compressible Cahn-Hilliard-Navier-Stokes equations discretized on staggered (MAC) grids. The scheme is based on finite difference approximations that ensure a stable coupling among the velocity, density and phase field, with symmetric operators acting on the discretized viscosity terms. Standard explicit methods suffer from severe time-step restrictions due to the presence of second to fourth-order diffusion terms introduced by the Cahn-Hilliard and Navier-Stokes operators. To overcome these challenges, we develop an IMEX Runge-Kutta scheme that treats the stiff terms implicitly while the convective terms are dealt with explicitly, with the advantage that only linear systems are solved at each stage. Numerical experiments are performed to verify the stability, accuracy and efficiency of the proposed approach.
format Preprint
id arxiv_https___arxiv_org_abs_2512_20351
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Implicit-explicit schemes for compressible Cahn-Hilliard-Navier-Stokes equations on staggered grids
Martorell, Andreu
Mulet, Pep
Yáñez, Dionisio F.
Numerical Analysis
We propose a second-order implicit-explicit (IMEX) time-stepping scheme for the isentropic, compressible Cahn-Hilliard-Navier-Stokes equations discretized on staggered (MAC) grids. The scheme is based on finite difference approximations that ensure a stable coupling among the velocity, density and phase field, with symmetric operators acting on the discretized viscosity terms. Standard explicit methods suffer from severe time-step restrictions due to the presence of second to fourth-order diffusion terms introduced by the Cahn-Hilliard and Navier-Stokes operators. To overcome these challenges, we develop an IMEX Runge-Kutta scheme that treats the stiff terms implicitly while the convective terms are dealt with explicitly, with the advantage that only linear systems are solved at each stage. Numerical experiments are performed to verify the stability, accuracy and efficiency of the proposed approach.
title Implicit-explicit schemes for compressible Cahn-Hilliard-Navier-Stokes equations on staggered grids
topic Numerical Analysis
url https://arxiv.org/abs/2512.20351