Microfluidics Module Updates
For users of the Microfluidics Module, COMSOL Multiphysics® version 6.1 introduces inelastic non-Newtonian property groups, materials for multiphase flow couplings, and a new Level Set in Porous Media interface. Learn more about these updates below.
Multiphase Materials for Multiphase Flow Couplings
For the Two-Phase Flow, Level Set, Two-Phase Flow, Phase Field, and Three-Phase Flow, Phase Field multiphysics couplings, there is now the option to include effective material properties from a Multiphase Material node, with built-in mixing rules. This is especially efficient when coupling these multiphysics interfaces with other physics, such as heat transfer or electrostatics, since the multiphase material will use appropriate mixing rules for nonfluid material properties. In older versions, this would require you to write user-defined expressions based on the volume fraction of each fluid phase to compute the effective material properties used in each physics interface. The following existing models showcase this new feature:
Liquid–air interface in a Taylor cone model. A liquid is displaced by the electrostatic forces caused by an electric field acting on the thin fluid–fluid interface. The relative permittivity used in the Electrostatics interfaces is computed by a multiphase material.
Inelastic Non-Newtonian Material Property Groups
Dedicated material property groups have been added for all available inelastic non-Newtonian models. Each material property group contains all necessary material parameters as well as the apparent viscosity expression. It picks up the shear rate from a Fluid Flow interface to define the dynamic viscosity for fluid by means of a synchronization rule. Thus, an inelastic non-Newtonian model can be selected directly by adding the corresponding Material Properties group as a subnode to a material node.
Level Set in Porous Media
In the Level Set interface, a new Porous Medium feature can now take the definition of the porosity given in the Porous Material node. The new Level Set in Porous Media interface includes this new feature by default. You can see this update in the new Resin Transfer Molding of a Wind Turbine Blade model.