A rectangular prism element (i.e., eight-node-linear element, rectangular parallelopiped element, trilinear hexahedral element, or brick) shown below is a basic element for three-dimensional domains, used in TechFlowMP model. In a natural coordinate system (ξ,η,ζ), a shape function (basis function) for a rectangular prism element with eight nodes is written as follows: with Local node numbers: The element has faces ξ = ±1, η = ±1 and ζ= ±1. Local boundary face (plane) number:
Read MoreOnce chlorinated volatile organic compounds (CVOCs) are released into the subsurface they are spread out through the porous soil matrix by complicated processes such as advection, dispersion, and sorption. CVOCs can be also biodegraded by indigenous microorganism via aerobic and anaerobic bioreactions, which generate distinct benign or harmful by-products. Heterogeneous subsurface characteristics and non-uniform distribution and consumption of oxygen in the subsurface may allow the dual bioreactions to coexist within a representative subsurface volume (RSV). The portion of each bioreaction within a RSV will depend on multiple factors such as oxygen, contaminant, and microorganism levels. Oxygen can be supplied into the contaminated zone through the dispersive and advective transport of oxygen in gas phase as well as the flow of the groundwater containing dissolved oxygen. As the dual bioreactions are coupled with multiple fluid flows (groundwater and gas) and multispecies transport, the analysis of the bioreactions is very complicated. However,
Read MoreTechFlowMP is a three-dimensional numerical model that simulates the flow of multiple fluids (or multiphases), the transport of multiple chemicals, microorganisms, and the transport of thermal energy (or heat) through porous media in the subsurface. Phases (Fluids): Groundwater, gas, and non-aqueous phase liquid (NAPL). Chemicals and Microbes Chemicals: Volatile organic compounds, such as PCE, TCE, DCEs, VC, and BTEX, and nutrients/oxygen. Microbes: Aerobes and anaerobes, and pathogens. Thermal energy: Heat transport through porous media (Nonisothermal subsurface environment). Transport mechanisms and processes: Advection, dispersion, and chemical and biological reactions in single/multiple phase flow. Numerical technique: Galerkin finite element method. Code information Programming language: C/C++ and Microsoft Visual C++ with object-oriented programming. Supporting platforms: Lunix, UNIX, and Microsoft Windows with Qt-based graphical user interfaces (GUIs). High performance computing: OpenMP. Document: Three-dimensional Multiphase Flow and Multi-species Transport Model, TechFlowMP, Multimedia Environmental Simulations Laboratory, School of Civil and Environmental Engineering,
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