Porous Media Flow Module
COMSOL Multiphysics® version 5.5 introduces the new Porous Media Flow Module. This add-on module allows you to model mass, momentum, and energy transport in porous media.
Porous Media Flow Module Overview
Porous media exist in many natural and man-made systems, and the need for advanced porous media modeling spans many industries. Examples include processes in fuel cells, drying of pulp and paper, food production, filtration processes, and so on. The Porous Media Flow Module extends the COMSOL Multiphysics® modeling environment to the quantitative investigation of mass, momentum, and energy transport in porous media. Its application areas range from conventional porous media flow, based on Darcy's law, to non-Darcian flow and multiphysics flow analysis, including the effects of heat transfer, chemical engineering, and more.
Porous Media Flow Module Functionality
Flow Models
The Porous Media Flow Module includes functionality for modeling single-phase flow in porous media based on Darcy's law, Brinkman's equations, and combinations of free and porous media flow. Fractures in porous media may dominate the flow and a specialized interface for fracture flow can be combined with any of the porous media flow models. Both stationary and time-dependent analysis types are available.
Multiphase Flow
The multiphase flow capabilities include transport of multiple immiscible phases through a porous medium, solving for averaged phase volume fractions. For variably saturated porous media, a nonlinear flow option, based on Richards' equation, can be used to analyze media where the hydraulic properties change as fluids move through the porous medium, filling some pores and draining others.
Multiphysics
The multiphysics capabilities include combinations with heat transfer, chemical engineering, and structural analysis. When combined with heat transfer, there are options for computing nonisothermal flows in porous media as well as effective thermal properties. Heat transfer in porous media can be combined with moisture transport for applications within consumer electronics, packaging materials, and building physics.
The module also treats the transport of chemical species in free flow, saturated, and partially saturated porous media. It can be used to study the flow and chemical composition of a gas or liquid moving through the interstices of a porous medium. Apart from porous media regions, the flow system may also include regions with free flow.
For elastic effects in a porous material, a specialized multiphysics interface for poroelasticity combines a transient formulation of Darcy's law with a quasistatic formulation of solid mechanics. The pore pressure from the Darcy's Law interface acts as a load for the structural analysis, thereby causing swelling or shrinking. Changes in volumetric strain affect the pore space, which acts as a mass source or sink for the Darcy's law flow model.
General Moisture Transport Interface Improvements
A new Concentrated species formulation is available in the Moisture Transport in Air interface to model convection and diffusion of vapor in air when the vapor content is high. This is often the case when there is moderate or high relative humidity at a high temperature. Under these conditions, the moist air density may vary significantly in space and time due to vapor concentration gradients, and the default formulation should be replaced by the new Concentrated species formulation.
The physics interface has also been improved to support supersaturation conditions that correspond to a relative humidity greater than one. This occurs when a hot stream saturated with water vapor is rapidly cooled down. Finally, the default solver settings for the various moisture transport, heat and moisture, and moisture flow interfaces have been set in a way that results in more robust and faster computation.
New Tutorial Models
The Porous Media Flow Module includes several tutorial models.
Packed Bed Latent Heat Storage
Application Library Title:
packed_bed_latent_heat_storage
Frozen Inclusion
Application Library Title:
frozen_inclusion