A structure-preserving numerical method for quasi-incompressible Navier-Stokes-Maxwell-Stefan systems
Aaron Brunk, Ansgar Jüngel, Maria Lukáčová-Medvid'ová
TL;DR
The paper develops a conforming finite element method with mixed explicit-implicit time discretization for the quasi-incompressible Navier–Stokes–Maxwell–Stefan system, ensuring mass preservation, pointwise quasi-incompressibility, and a discrete energy inequality. It provides a rigorous variational formulation, derives discrete identities and a priori bounds, and demonstrates convergence and structure-preserving behavior through two- and three-component 2D experiments, including a relative energy analysis. The work advances numerical analysis and simulation capability for multicomponent, cross-diffusion flows by delivering a robust, energy-stable discretization that respects the coupled physics. This framework lays groundwork for error estimates and higher-order structure-preserving schemes, with potential applications to complex fluids and electrolyte transport problems.
Abstract
A conforming finite element scheme with mixed explicit-implicit time discretization for quasi-incompressible Navier-Stokes-Maxwell-Stefan systems in a bounded domain with periodic boundary conditions is presented. The system consists of the Navier-Stokes equations, together with a quasi-incompressibility constraint, coupled with the cross-diffusion Maxwell-Stefan equations. The numerical scheme preserves the partial masses and the quasi-incompressibility constraint and dissipates the discrete energy. Numerical experiments in two space dimensions illustrate the convergence of the scheme and the structure-preserving properties.
