How the Subsurface Flow Module Helps Improve Your Modeling
The earth and surrounding planets are a giant laboratory filled with an unlimited array of basic physics and multiphysics interactions. Whether in concert or alone, these physical phenomena alter our access to important resources, affect the quality of the environment, shape the ground beneath our feet on earth, and form other planets.
The Subsurface Flow Module is used in the quantitative investigation of geophysical and environmental phenomena, especially within the area of subsurface flow. The module combines physics interfaces for fundamental processes and links to COMSOL Multiphysics and the other modules for structural mechanics and electromagnetics analyses. New physics represented include heating from radiogenic decay that produces the geotherm, which is the increase in background temperature with depth. You can use the variably saturated flow interfaces to analyze unsaturated zone processes (important to environmental engineers) and two-phase flow (of particular interest in the petroleum industry as well as steam-liquid systems). Important in subsurface flow, the heat transfer and chemical transport interfaces explicitly account for physics in the liquid, solid, and gas phases.
The physics interfaces, options, and functions are tailored to account for subsurface flow and geologic process terminology. The Heat Transfer interfaces, for example, include features to superpose a background geotherm without incorporating it as a boundary condition. These physics interfaces also include options to automate the calculation of effective thermal properties for multicomponent systems.
The Fluid Flow branch represent a wide range of possibilities. The Richards’ Equation interface describes nonlinear flow in variably saturated porous media. The options for saturated porous media include the Darcy’s Law interface for slow flow and the Brinkman Equations interface where shear is nonnegligible. The Laminar Flow interface uses the Navier–Stokes equations to cover free flows and the Fracture Flow interface is used for modeling flow in fractures.
The module also treats the transport of chemicals and their reactions with the Chemical Species Transport branch. The Transport of Diluted Species in Porous Media interface account for chemical transfer in solid, liquid, and gas phases for free, saturated, and variably saturated fluid flows. The Subsurface Flow Module Application Library has a number examples linking these physics interfaces together.