Subsurface Flow Module Updates

For users of the Subsurface Flow Module, COMSOL Multiphysics® version 5.6 brings updated features for the existing Transport of Diluted Species and Heat Transfer in Porous Media interfaces, a new Shallow Water Equations, Time Explicit interface, and a new add-in for creating Discrete Fracture Networks (DFN). Learn more about these subsurface flow updates below.

Revamped Porous Media Features for Transport of Diluted Species

The Transport of Diluted Species in Porous Media interface is revamped to use the new Porous Medium node. Two new domain features, the Porous Medium and the Unsaturated Porous Medium nodes, are available in the Transport of Diluted Species in Porous Media interface. You can use the new Porous Medium node for assigning material properties to the multiple phases in a porous medium. The new nodes have dedicated containers to define the properties for the liquid, gas, and porous matrix.

You can find this feature in the following models:

A closeup view of the COMSOL Multiphysics version 5.6 UI with the settings shown for Transport of Diluted Species in Porous Media and a pesticide transport model in the Graphics window.
Contaminant concentration in unsaturated soil.

Revamped Porous Media Features for Heat Transfer

The Porous Medium node in the Heat Transfer interface has been revamped. The solid and fluid phases are now handled in dedicated containers, namely the Porous Matrix and Fluid nodes. The computation of the effective material properties is handled in the Porous Medium node, whereas the solid and fluid properties are entered in the Porous Matrix and Fluid subnodes. You can also include an additional immobile fluid phase by adding an Immobile Fluid node.

In the new Porous Medium node, the settings are homogenized with those of the porous media features in the fluid flow and chemical species transport interfaces. In particular, the Porosity is now specified instead of the volume fraction of the solid phase. Additionally, you can set either the Dry bulk properties or the Solid phase properties, depending on the availability of these material properties.

With the new design, you can take advantage of the new Porous Material functionality under the Materials node, in which the porosity, volume fractions, and material properties are set in dedicated containers to each phase: the Solid, Fluid, and Immobile Fluid nodes. You can see this new functionality in the following models:

A closeup view of the COMSOL Multiphysics version 5.6 UI with settings shown for Porous Material and a frozen inclusion model in the Graphics window.
Frozen inclusion model uses the new Porous Material and Porous Medium feature.

New Add-In for Creating Discrete Fracture Networks (DFN)

Fracture networks are an important mechanism that enhances mass, momentum, and energy transport in groundwater flow, geothermal and petroleum reservoirs, nuclear waste storage sites, and more. A new add-in is available for creating Discrete Fracture Networks in realistic geometries, such as reservoirs and rock formations. The add-in works for both 2D and 3D geometries. You can view the new add-in feature in the Flow in a Fractured Reservoir model.

A closeup view of the COMSOL Multiphysics version 5.6 UI with the settings shown for Discrete Fracture Network and a fractured reservoir model in the Graphics window.
Flow in a fractured reservoir using the Discrete Fracture Network add-in.

Shallow Water Equations

The shallow water approximation is frequently applied in oceanographic and atmospheric applications to predict effects of tsunami impacts, areas affected by pollution, coastal erosion, and polar ice cap melting, to mention a few. The new Shallow Water Equations, Time Explicit interface uses a depth-averaged formulation to solve free-surface flows in 1D and 2D domains. The bottom topography in a model can conveniently be defined from a digital elevation model (DEM). You can see this feature in the new Tsunami Runup onto a Complex 3D Beach, Monai Valley and Dam Breaking on a Column, Shallow Water Equations tutorial models.

Tsunami impact simulated with the Shallow Water Equations, Time Explicit interface.

New Tutorial Models

COMSOL Multiphysics® version 5.6 brings several new tutorial models to the Subsurface Flow Module.

Flow in a Fractured Reservoir

A model of a fractured reservoir with a partially transparent top to give a look inside.
Darcy velocity in fractures, created using the Discrete Fracture Network add-in.

Application Library Title:
fractured_reservoir_flow

Download from the Application Gallery

Analyzing Porous Structures on the Microscopic Scale

A model of a porous structure with pale green streamlines to denote flow.
Flow through a complex porous structure.

Application Library Title:
pore_scale_flow_3D

Download from the Application Gallery

Tsunami Runup onto a Complex 3D Beach, Monai Valley

Three models of a gray beach and blue water representing tsunami runup.
Shallow water equations simulation of tsunami runup onto a beach. Water level at 0, 15, and 25 s.

Application Library Title:
monai_runup

Download from the Application Gallery

Dam Breaking on a Column, Shallow Water Equations

A model of a gray square column with blue water breaking on the column.
Shallow water equations simulation of a wave breaking at a column.

Application Library Title:
dam_break_column_sw

Download from the Application Gallery