COMSOL Multiphysics^® 6.4 Release Highlights

For users of the Subsurface Flow Module, COMSOL Multiphysics^® version 6.4 introduces a new feature to specify periodicity between two or more boundaries, a new permeability model, a new option in the Free and Porous Media Flow Coupling feature to include a pressure jump across the free–porous boundary. Learn more about these updates below.

Periodic Condition

A new Periodic Condition feature has been added to the Darcy's Law and Richards' Equation interfaces to easily enforce periodicity for the flow between two or more boundaries. In addition, it is possible to create a pressure difference between source and destination boundaries, either by specifying the pressure jump directly or by prescribing a mass flow. The model Estimating Permeability from Microscale Porous Structures showcases this new feature. The periodic condition is typically used to model representative volume elements and compute effective properties for use in homogenized porous media.

Using the new Periodic Condition feature to estimate the permeability of a porous medium consisting of a periodic array of spheres.

Power Law Permeability Model

For reservoir and groundwater simulations, the new Power law permeability model can be used to capture the nonlinear dependence between porosity and permeability. This model estimates permeability as a function of porosity using a power-law relationship. Try out this functionality in the Estimating Permeability from Microscale Porous Structures and Seawater Intrusion in a Coastal Aquifer tutorial models.

The Power law permeability model is used to define the permeability of the coastal aquifer.

Pressure Jump Option for the Free and Porous Media Flow Coupling

The Free and Porous Media Flow Coupling has a new option to include a pressure jump across the free–porous boundary. This makes it possible to model, as examples, the osmotic pressure at a semipermeable membrane supported by a porous spacer material or a pressure jump due to capillary pressure in the case of multiphase flow. The Reverse Osmosis Water Desalination tutorial model demonstrates this new option.

Using the new Include pressure jump across free–porous boundary checkbox for the Free and Porous Media Flow Coupling to model the osmotic pressure at a thin semipermeable membrane in a desalination unit.

New and Updated Models

COMSOL Multiphysics^® version 6.4 brings new and updated tutorial models to the Subsurface Flow Module.

Artificial Ground Freezing for Tunnel Excavation

Formation of an ice barrier around freezing pipes and ground deformation during artificial ground freezing. The model shows the complex thermohydromechanical interactions between heat transfer, groundwater flow, and soil mechanics. The model requires the Structural Mechanics Module.

Application Library Title:
artificial_ground_freezing
Download from the Application Gallery

Borehole Heat Exchanger

Temperature isosurfaces after one year of operation around an array of borehole heat exchangers (BHEs) used for shallow geothermal energy production. The BHEs are embedded within a layered subsurface model with groundwater flow in one of the geological layers.

Application Library Title:
borehole_heat_exchanger
Download from the Application Gallery