title: Simulation of gaseous diffusion in partially saturated porous media under variable gravity with lattice Boltzmann methods.
abstract: Liquid distributions in unsaturated porous media under different gravitational accelerations and corresponding macroscopic gaseous diffusion coefficients were investigated to enhance understanding of plant growth conditions in microgravity. We used a single-component, multiphase lattice Boltzmann code to simulate liquid configurations in two-dimensional porous media at varying water contents for different gravity conditions and measured gas diffusion through the media using a multicomponent lattice Boltzmann code. The relative diffusion coefficients (D rel) for simulations with and without gravity as functions of air-filled porosity were in good agreement with measured data and established models. We found significant differences in liquid configuration in porous media, leading to reductions in D rel of up to 25% under zero gravity. The study highlights potential applications of the lattice Boltzmann method for rapid and cost-effective evaluation of alternative plant growth media designs under variable gravity.
authors.affiliation: Department of Civil and Environmental Engineering, University of Connecticut, Storrs, Connecticut, USA. chau@engr.uconn.edu
authors.forename: Jessica Furrer
authors.initials: JF
authors.lastname: Chau
authors.forename: Dani
authors.initials: D
authors.lastname: Or
authors.forename: Michael C
authors.initials: MC
authors.lastname: Sukop
mesh_terms: D003198:Computer Simulation; D003470:Culture Media; D004058:Diffusion; D018504:Ecological Systems, Closed; D005740:Gases / Q000737:chemistry*; D006112:Gravitation; D018527:Hydroponics; D008021:Life Support Systems; D008962:Models, Theoretical; D018517:Plant Roots / Q000254:growth & development; D016062:Porosity; D012987:Soil; D013026:Space Flight; D014867:Water / Q000737:chemistry; D014893:Weightlessness
chemical_list: D003470:Culture Media; D005740:Gases; D012987:Soil; D014867:Water