A fully implicit coupled pore-network/free-flow model for the pore-scale simulation of drying processes. Issue 4 (22nd February 2022)

• Record Type: Journal Article
• Authors: Weishaupt, K.; Koch, T.; Helmig, R.
• Is Part Of: Drying technology. Volume 40:Issue 4(2022)
• Page Start: 697
• Page End: 718
• Publication Date: 2022-02-22
• Subjects: Dynamic pore-network model -- multi-physics simulation -- two-phase flow in porous media -- evaporation and drying -- pore-network Navier–Stokes coupling; Drying -- Periodicals; Desiccation; 660.28426
• DOI: 10.1080/07373937.2021.1955706
• Languages: English
• ISSNs: 0737-3937

Abstract

Abstract: We present a fully coupled pore-network/free-flow model providing pore-scale insight into drying processes. We solve the Navier–Stokes equations with component transport in the free-flow region, coupled to a dynamic two-phase, two-component pore-network model (PNM) in the porous domain. The dynamic multi-physics model allows to temporally resolve drying processes in-between capillary equilibrium states. All simulations are non-isothermal and use pressure- and temperature-depended fluid properties. Carefully chosen coupling conditions and a monolithic solver ensure local conservation of mass, momentum, and energy fluxes, in particular at the interface between both model domains. We solve for wetting and non-wetting fluid pressure fields and consider advective gas transport in the network. Numerical examples demonstrate that the coupled model is able to cover a wide range of physical processes relevant for drying and show the mutual interaction of the two subregions. The model is implemented in the modular open-source framework DuMu x such that extensions are straight-forward.