Concentration driven phase transitions in multiphase porous media with application to methane oxidation in landfill cover layers

Abstract

This study focuses on a formulation within the theory of porus media for continuum multicomponent modeling of bacterial driven methane oxidation in a porous landfill cover layer which consists of a porous solid matrix (soil and bacteria) saturated by a liquid (water) and gas phase. The solid, liquid, and gas phases are considered as immiscible constituents occupying spatially their individual volume fraction. However, the gas phase is composed of three components, namely methane (CH4), oxygen (O2), and carbon dioxide (CO2). A thermodynamically consistent constitutive framework is derived by evaluating the entropy inequality on the basis of Coleman and Noll [8], which results in constitutive relations for the constituent stress and pressure states, interaction forces, and mass exchanges. For the final set of process variables of the derived finite element calculation concept we consider the displacement of the solid matrix, the partial hydrostatic gas pressure and osmotic concentration pressures. For simplicity, we assume a constant water pressure and isothermal conditions. The theoretical formulations are implemented in the finite element code FEAP by Taylor [29]. A new set of experimental batch tests has been created that considers the model parameter dependencies on the process variables; these tests are used to evaluate the nonlinear model parameter set. After presenting the framework developed for the finite element calculation concept, including the representation of the governing weak formulations, we examine representative numerical examples.

Numerical investigations of diffusion coefficients in the context of multi‐component gas transport within the Theory of Porous Media

“…RICKEN ET AL. [3]. The (un-)saturated body is assembled by the solid phase (S), gas phase (G) and liquid phase (L), whereas the liquid phase can be dropped in case of an unsaturated medium.…”

Optimal remediation design and simulation of groundwater flow coupled to contaminant transport using genetic algorithm and radial point collocation method (RPCM)

“…The analytical approaches are applicable only when the boundary conditions and the geometries are simplified (Zheng and Bennett, 2002), while the numerical strategies can be applied to many sophisticated problems. There are different numerical approaches, including finite difference method (FDM) (Tatalovich et al, 2000), finite volume method (FVM) (Bertolazzi and Manzini, 2004), finite element method (FEM) (Robeck et al, 2011;Ricken et al, 2014;SCHMUCK et al, 2016;Seyedpour and Ricken, 2016), and boundary element method (BEM) (Leo and Booker, 1998) which can be used to solve the governing equation of groundwater flow and contaminant transport. Although their success in dealing with geometry complexity and heterogeneity, they encounter some difficulties in a simulation of high advection velocities and the low diffusion resulting in high Peclet number and also low dispersivities.…”

Model Order Reduction (MOR) of Function‐Perfusion‐Growth Simulation in the Human Fatty Liver via Artificial Neural Network (ANN)

“…[8] the total body ϕ consists of κ different phases ϕ α , including (ν − 1) miscible substances ϕ αβ According to RICKEN ET AL.…”