Image made using the COMSOL Multiphysics® software.
Flow through a packed-bed latent heat storage tank.
Porous media are encountered in many natural and man-made systems. The need for advanced porous media modeling spans many industries and application areas such as 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. It combines physics interfaces for fundamental processes and links to COMSOL Multiphysics and the other modules for structural mechanics and electromagnetics analyses. Important in industrial porous media flow, the heat transfer and chemical transport interfaces explicitly account for physics in the liquid, solid, and gas phases and include the possibility to model thermal nonequilibrium. The physics interfaces for heat transfer also include options to automate the calculation of effective thermal properties for multicomponent systems.
Thermal energy storage units are used to accumulate thermal energy from solar, geothermal, or waste heat sources. The simplest units are built from water tanks, often found in households, where the solar energy is stored as sensible heat. The thermal capacity of these tanks can be further increased by including latent heat, which gives rise to latent heat storage (LHS) units. Typically, LHS tanks contain spherical capsules filled with paraffin as phase change material. This example models the flow through a packed-bed storage tank, and it includes the effects of heat transfer with phase change and local thermal nonequilibrium while charging the LHS unit.
This example treats the modeling of sub-surface flow where free convection in porous media is analyzed. The results are compared with published literature in the field.
The model couples the momentum balance to an energy balance through an equation, dependent on temperature, being directly typed into the source term for the momentum balance. This shows COMSOL Multiphysics’ unique equation-based modeling abilities and can be considered as a benchmark model for COMSOL Multiphysics capabilities in single-phase porous media flow.
This example models wicking in a porous medium. Wicking is the phenomenon that occurs when a dry porous material is put into contact with a fluid: it will absorb the fluid due to capillary forces. The absorption will continue until an equilibrium is reached where the gravitational forces balance the capillary forces.
This example illustrates how to model the transport of different contaminants through a ceramic water filter candle with an activated carbon core. These types of water filters can be found in table top gravity filters, as well as attached to the faucet or as part of a larger reverse osmosis filter system. The tutorial shows how to set up the flow and transport equations to model different filter mechanisms. It also examines the effect of a small fracture in the ceramics part.
This example demonstrate two-phase flow in a porous medium which contains a low permeable lens. The heavier phase infiltrates the porous medium, so the low permeable lens is infiltrated only when a critical saturation at the outside is reached.
This 2D stationary model computes heat and moisture transport in a wall composed of different hygroscopic materials. A comparison with the Glaser method is given for the temperature and relative humidity solutions. The effect of the use of a vapor barrier is also investigated.
This model demonstrates the use of the Heat and Moisture Flow features for the simulation of superheated steam drying of a wood particle. A nonequilibrium formulation is used to compute the transport of the liquid water and vapor phases in the wood particle.
