title: A multi-component two-phase flow algorithm for use in landfill processes modelling.
abstract: This paper describes the finite difference algorithm that has been developed for the flow sub-model of the University of Southampton landfill degradation and transport model LDAT. The liquid and gas phase flow components are first decoupled from the solid phase of the full multi-phase, multi-component landfill process constitutive equations and are then rearranged into a format that can be applied as a calculation procedure within the framework of a three dimensional array of finite difference rectangular elements. The algorithm contains a source term which accommodates the non-flow landfill processes of degradation, gas solubility, and leachate chemical equilibrium, sub-models that have been described in White and Beaven (2013). The paper includes an illustration of the application of the flow sub-model in the context of the leachate recirculation tests carried out at the Beddington landfill project. This illustration demonstrates the ability of the sub-model to track movement in the gas phase as well as the liquid phase, and to simulate multi-directional flow patterns that are different in each of the phases.
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK. Electronic address: j.white@btinternet.com.
authors.forename: J K
authors.initials: JK
authors.lastname: White
authors.affiliation: FEESA Ltd, Westmead House, Westmead, Farnborough, Hants GU14 7LP, UK.
authors.forename: D
authors.initials: D
authors.lastname: Nayagum
authors.affiliation: Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
authors.forename: R P
authors.initials: RP
authors.lastname: Beaven
mesh_terms: D000465:Algorithms; D057446:Hydrodynamics; D008962:Models, Theoretical; D018505:Waste Management
keywords: Degradation; Gas; Landfill; Leachate; Modelling; Recirculation