New SFB 1313 publication, published in Computational Geosciences. The paper has been prepared within SFB 1313's research project A02 and is a cooperation work between the Technical University of Denmark (DTU) and the University of Stuttgart:
Authors
- Navid Ahmadi (Technical University of Denmark)
- Katharina Heck (University of Stuttgart, research project A02)
- Massimo Rolle (Technical University of Denmark)
- Rainer Helmig (University of Stuttgart, research projects A02 and C02)
- Klaus Mosthaf (Technical University of Denmark)
Abstract
Multicomponent gas transport in porous media and at the interface between porous media and free flow occurs in a wide range of technical and environmental systems. Modeling tools are required for the quantitative description of such coupled environmental compartments. We present a benchmark study to compare different diffusion models as well as different coupling concepts employed for the description of multicomponent gas flow and transport at the porous medium/free-flow interface. The benchmark problems allowed us to compare two diffusion models (Fickian and Maxwell-Stefan formulations) for predicting the transport behavior of multicomponent mixtures in porous media and in presence of a free flow. The examples highlighted the importance of interaction between different diffusing components by applying the Maxwell-Stefan formulation, as well as the impact of the free flow velocity on gas migration at the interface under diffusion- and advection-dominated conditions. The problems were solved using two simulation tools, incorporating different coupling concepts to describe the physics of flow and transport processes. In COMSOL Multiphysics, we implemented a single-domain Brinkman approach, whereas in the DuMuX simulator we used a two-domain approach with the Navier-Stokes equation for the free flow and Darcy’s law for the porous medium. Also, the formulation of the Maxwell-Stefan equation for multicomponent transport was different between the two codes. Despite the different modeling concepts, mathematical descriptions and numerical schemes implemented in the two simulators, their outcomes demonstrate excellent agreement for all benchmark problems, as well as the capability to reproduce the results of previous modeling and experimental studies.
Katharina Heck
Dr.-Ing.Postdoctoral Researcher, Management, Research Project A02, Project MGK
Rainer Helmig
Prof. Dr.-Ing. Dr.-Ing. h.c.Principal Investigator, Former Spokesperson, Research Projects A02 and C02, Central Project Z