COMSOL 4.3a Release Highlights

Table of Contents
New Products

LiveLink™ for Excel®

Run COMSOL Multiphysics® simulations directly from a spreadsheet with LiveLink™ for Excel®. Parameters and variables used in COMSOL Multiphysics are instantly available in Microsoft® Excel and automatically synchronized to your physics model.

LiveLink™ for Excel® allows for a simplified workflow where you only need to display and edit the most important simulation parameters. Interactive 3D visualizations are presented in a separate dedicated canvas. Using LiveLink™ for Excel® automatically adds a COMSOL® tab to the Excel ribbon for controlling the mesh or running a simulation. You can also import/export Excel files for parameter and variable lists in the COMSOL Desktop GUI. LiveLink™ for Excel® currently requires Excel 2007 or 2010 for Windows®.

Learn more
Livelink™ for Excel®
Here, LiveLink™ for Excel® is used for a parameterized high-power direct current simulation of a bus bar. The parameters controlling the geometric dimensions as well as the applied voltage are edited in an Excel spreadsheet and synchronized to the underlying COMSOL Multiphysics model. A dedicated ribbon tab is added to Excel for easy access to parameters, variables, functions, geometry, mesh, solvers, and results.

Fatigue Module

The Fatigue Module enables structural fatigue life computations in the COMSOL Multiphysics environment. Both high-cycle and low-cycle fatigue methods are available, based on stress and strain, respectively.

For stress-based fatigue, the Fatigue Module provides the methods of Findley, Matake, and Normal Stress. For strain-based fatigue, the available methods are Smith-Watson-Topper, Wang-Brown, and Fatemi-Socie. The Fatigue Module features Neuber's rule and the Hoffmann Seeger method for an approximate elastoplastic solution.

In addition, a full elastoplastic fatigue evaluation is available when combining the Fatigue Module with the Nonlinear Structural Materials Module. Results include visualization of fatigue life based on the number of cycles until failure as well as fatigue usage factor. The Fatigue Module is available as an add-on to the Structural Mechanics Module.

Learn more
Fatigue Module
Elastoplastic low cycle fatigue (LCF) analysis of a cylinder with a hole. The last of two load cycles is used for the fatigue analysis to make sure that the state is representative for repeated loadings.

ECAD Import Module

You can now create 3D geometry models from ECAD layouts using the ECAD Import Module. Using any of the ODB++(X), GDS-II, and NETEX-G file formats, you can select which subset of cells, nets and layers to import, edit layer thickness, control the geometric representation of bond wires, and include selected dielectric regions.

The layout is automatically extruded and converted to a 3D CAD model for use in any kind of COMSOL Multiphysics simulations with any combination of add-on products.

Learn more
Nonlinear Structural Materials Module
Capacitance and inductance extraction for a planar transformer model imported as an ECAD file. This type of device is used in power supplies and DC/DC converters where a slim high-power design is crucial. The entire layout, including the footprint of the transformer ferrite core, is imported from an ODB++(X) file. The ECAD Import Module is used to read the layout and automatically create a 3D geometry model of the Printed Circuit Board (PCB) and the ferrite core.

LiveLink™ for Solid Edge®

LiveLink™ for Solid Edge® delivers a seamless integration of CAD and simulation. By establishing an associative connection between the two applications, a change of a feature in the CAD model automatically updates the geometry in COMSOL Multiphysics, while retaining physics settings. All parameters specified in Solid Edge® can be interactively linked with your simulation geometry. This enables multiphysics simulation involving parametric sweeps and design optimization directly from within the CAD program.

LiveLink™ for Solid Edge® includes all the capabilities of the CAD Import Module. This lets you import and defeature files from all major CAD packages.

Learn more
Corrosion Module
An oil rig structure immersed in seawater is protected by 52 sacrificial aluminum anodes. Before deploying the anodes, the Corrosion Module is used to optimize their positions for the best possible corrosion protection. Visualized is the electrolyte potential on the surface of the structure. The geometry model in Solid Edge is synchronized to COMSOL Multiphysics through LiveLink™ for Solid Edge®.
Studies and Solvers

Export of Reduced Order System Matrices

When using the Modal Solver, you can now export the reduced-order system matrices and vectors including stiffness matrix, mass matrix, and load vector. Under Derived Values in Results, you can add a System Matrix node where you specify which of the computed system matrices to output and whether to output them using a sparse or full format.

View Screenshot

Importing System Matrices using the Java API

Input of system matrices generated outside of the COMSOL Multiphysics simulation environment is made possible using a new Input Matrix subnode to a solver node. Specify which system matrices and vectors should use external data from the Java API. The saved Model Java-file contains program code for inputting the selected matrices and vectors.

View Screenshot

Get Initial Value and Compute Selected Study Steps

Get Initial Value is available as an option on the Study level and for each study step. Use this to evaluate the solution and variables using the initial values. This makes it possible to plot and evaluate the solution and any solution-dependent variables using the initial values as the solution. It can also be used as a quick way to get access to the visualization and postprocessing tools of the Results node.

View Screenshot

Run Your Models in the Cloud

You can now run COMSOL Multiphysics simulations in the cloud, through Amazon Elastic Compute Cloud™ (Amazon EC2™). Cloud computing is used to access high-end virtual computers and clusters on a pay-per-use basis. Cloud computing is available in version 4.3a for any COMSOL Multiphysics user with a floating network license.

Running COMSOL Multiphysics in the cloud gives you access to three types of computations:

  • Multicore Computing on one single fast virtual computer with large amounts of memory.
  • Cluster Sweep for parallel parametric studies.
  • Cluster Computing for large distributed memory simulations.

Cloud computing is made possible by new remote and cloud access tools which minimize the amount of data transferred when uploading or downloading model information to or from the cloud. A new dial-back utility connects to your on-premise license manager-- using your existing floating networks licenses. Cloud computing is available from the COMSOL Desktop GUI as well as from batch mode.

View Screenshot
Mesh and Geometry
Corrosion Module
A 2D geometry used to illustrate the new tool for automatic mesh refinement of reentrant corners as well as boundary-layer meshing of interior boundaries. These features are also available for 3D meshing.

Tailored Mesh Settings for CFD

Version 4.3a introduces new automatic meshing tools tailored for CFD. Automatic corner refinement finds all of the reentrant corners in a user-selected group of boundaries and applies mesh refinement.

Trimming is now applied at sharp corners for boundary-layer mesh creation. This feature is integrated with the default geometric multigrid solver for CFD and is both robust and accurate for larger geometry models.

Interior boundaries are often used to represent very thin objects such as membranes or shells. Boundary-layer meshing is now also available for interior boundaries in such cases.

Corrosion Module
A boundary layer mesh in 3D with automatic corner refinement and new handling of sharp edges.

Mesh Selection Tools for Imported Mesh

Additional tools are available for mesh selections used to subdivide an imported mesh. A mesh which was not created with COMSOL's native mesh generator but imported from other software may not have the desired domain and boundary partitioning. COMSOL Multiphysics features a series of selection operations which allow grouping of existing mesh elements and make it easy to assign boundary conditions and material properties where desired.

A selection tool has been added which allows you to use the x, y, and z coordinates in a logical expressions such as (y<-40)&&(z>2.5) to partition an imported mesh into new domains or boundaries. The previously available coordinate-based Ball and Box selections now give visual feedback in the form of a wireframe plot representing the size and position of the Ball and Box, respectively.

Corrosion Module
Partitioning a mesh based on a logical expression in terms of coordinate variables x, y, and z.

Geometry Selection Tools

You can select all adjacent boundaries and edges in a geometry model with a continuous tangent by using the Explicit, Ball, Box, and Cylinder selection features. By just selecting a single face, the selection is propagated to all adjacent boundaries with a continuous tangent within a user-defined angular tolerance.

The new Cylinder selection makes it possible to use a coordinate-based cylinder for selecting objects in a geometry. This selection type is similar to the Box and Ball selection features and can simplify selection of geometric entities in suitable geometries.

Corrosion Module
Selection of boundaries in geometry models such as this exhaust manifold is made easier by the new continuous tangent selection.

Import of Contour Plots for use in Geometry Modeling

The Interpolation Curve feature can now read curve coordinates from file on the Sectionwise data format in addition to the spreadsheet data format. You can also specify the curves as vectors of x, y, and z coordinates. This makes it possible to export contour plots of a solution or mathematical expression in Sectionwise data format, which in turn allows them to be imported and reused as an interpolation curve in a geometry model. In this way, contour plots can be used to create curves in 2D, or extruded, revolved, or swept to surfaces in 3D.

Corrosion Module
An isothermal contour line is exported and then imported as an interpolation curve, extruded, and used to partition this geometry of a power transistor on a circuit board.
Fast Multicore and Cluster Computing

Fast Parallel Computing

Version 4.3a offers more efficient parallel computing for both shared-memory/multicore and distributed systems.

For multicore computing, handling of constraint boundary conditions is greatly improved. This includes boundary conditions such as fixed temperature, electric potential, and displacement. It also speeds in computations for most physics. New constraint elimination algorithms are the primary reason for this increase in performance.

For distributed computing, the solvers have been optimized by the introduction of a very efficient sparse matrix reordering algorithm for direct solvers. In addition, communication for matrix-vector data has been optimized.

View Screenshot
The radiation pattern from a microstrip patch antenna

The Intel® Concurrency Checker used to benchmark a COMSOL Multiphysics simulation on an Intel multicore processor. Read more about this type of benchmark at the COMSOL Blog

Results and Visualization

Visualization and Animation News

A new transparent background option for images exported on the PNG format makes it easier to integrate COMSOL images into your documents and combine them with other graphics.

Placement and display of labels on logarithmic x- and y-axes have been improved. Legend positioning now also comes with a Middle Left and Middle Right option.

Animation default settings have been improved with better support for animating parametric solutions and the ability to specify the number of frames in the generated movie.

Mesh Selections for Creating New Boundaries and Domains

The new transparent background option for image export makes it easy to quickly combine visualizations in documents. The pictures show a microfluidics simulation.

Optimization Module

Parameter Optimization

Parameter optimization can now be applied to any COMSOL Multiphysics model thanks to the addition of three new gradient-free optimization methods: Nelder-Mead, Coordinate Search, and Monte Carlo. These gradient-free methods make it possible to optimize one or more geometric dimensions for a CAD model created directly in COMSOL Multiphysics or via the LiveLink™ products.

You can implement the new optimization methods from a new Optimization study type for general gradient-free optimization. Control parameters are not limited to geometric dimensions but can represent nearly any quantity in a model including parameters controlling the mesh.

A tunable MEMS capacitor where a target capacitance of 0.1 pF is found by optimizing with respect to the distance between capacitor plates. The pictures show three different configuration for different offset distances of the lower capacitor plate. The target capacitance is found for the offset value of 12.5 µm.
Particle Tracing Module

Diffuse Reflection, General Reflection, and Pass Through Boundary Conditions

New boundary conditions are available for Diffuse and General Reflection. You can supply user-defined expressions for the particle velocity after collision with a wall.

A new Pass Through boundary condition can be used on interior boundaries in conjunction with a sticking probability or expression.

View Screenshot

New Variables for Particle Release Time, Stop Time, and Status

In the Particle Tracing Module, new variables have been added for: particle release time, particle stop time, and particle status. This makes it easier to work with particle tracing in cases where automatic remeshing is used. To activate, set the Store Particle Status Data to On. The new variables make it easier to compute residence time.

View Screenshot
CAD Import and LiveLink Products

New Version Support and Removal of Redundant Data

For CAD import, you can now select a check box to remove non-essential and redundant edge and vertex information when importing a geometry model. By default this option is not selected and all edges and vertices are kept.

For the file-based CAD import in the CAD Import Module and all LiveLinks for CAD products, the following updated file formats are now supported:

  • Catia® V5 R 22
  • Parasolid V 25

View Screenshot

LiveLink™ for AutoCAD®

AutoCAD 2013 is now supported by LiveLink™ for AutoCAD®

LiveLink™ for Inventor®

Associativity is now maintained without writing information to the CAD file.

LiveLink™ for Pro/ENGINEER®

Parameters and user-defined parameters are now transferred together with their units to COMSOL.

LiveLink™ for Creo™ Parametric

Creo Parametric 2.0 is now supported. Parameters and user-defined parameters are now transferred together with their units to COMSOL.

LiveLink™ for MATLAB®

You can now use the function mphinputmatrix to add a linear system matrix to a model. The function arguments are the model object, a MATLAB structure, and solver information. It supports the solver types Stationary, Eigenvalue, and Time.

Sparce Matrix Manipulation
A new tutorial for LiveLink™ for MATLAB® showing how to modify the system matrices of a COMSOL model by directly manipulating the sparse matrix information.
AC/DC Module

TEAM 7 Benchmark Model and Wire Gauge for Multi-Turn Coils

The new benchmark example Multi-Turn Coil Above an Asymmetric Conductor Plate solves the Testing Electromagnetic Analysis Methods (TEAM) problem 7. The original TEAM name of this benchmark is “Asymmetrical Conductor with a Hole”. The objective is to calculate the eddy currents and magnetic fields produced when an aluminum conductor is placed asymmetrically above a multi-turn coil carrying an AC current. The simulation results at specified positions in space agree with measured data from given literature references.

For the Multi-Turn Coil Domain feature, a new set of wire gauge options are now available: Standard wire gauge, American wire gauge, From round wire diameter, and User defined.

New Tutorial and Benchmark Models

Three new tutorial models illustrate induced currents in an iron sphere at different frequencies: 60 Hz, 20 kHz, and 13 MHz. Depending on the frequency, different modeling approaches are applied. For the 13 MHz case, for instance, the skin depth is thin enough that only the surface of the iron sphere needs to be considered.

In a new tutorial, a sphere of relative permeability greater than unity is exposed to a spatially uniform, static, background magnetic field. The field strength inside the sphere is computed and benchmarked against an analytic solution.

RF Module

Periodic Ports

A new port boundary condition for modeling of periodic structures is available for the 2D Electromagnetic Waves user interfaces. Periodic ports make it easier to model excitation of structures with Floquet periodicity and include automatic setup of diffraction orders.

The radiation pattern from a microstrip patch antenna

The Plasmonic Wire Grating tutorial has been updated and now utilizes the new periodic ports. In this example, a plane wave is incident on a wire grating on a dielectric substrate. Coefficients for refraction, specular reflection, and first-order diffraction are all computed as functions of the angle of incidence.

Mapped Dielectric Distribution of a Metamaterial Lens

This example demonstrates how to set up a spatially varying dielectric distribution, which could be engineered with a metamaterial. Here, a convex lens shape is defined via a known deformation of a rectangular domain. The dielectric distribution is defined on the undeformed, original rectangular domain and is mapped onto the deformed shape of the lens. Although the lens shape defined here is convex, the dielectric distribution causes the incident beam to diverge.

New 2D Formulations and Volume Currents

New in-plane formulations for the in-plane 2D and axisymmetric 2D Electromagnetic Wave formulations includes an out-of-plane wavenumber. The in-plane 2D formulation makes it easier to model 2D periodic gratings, periodic structures with out of plane incidence, and slab waveguides. The axisymmetric 2D formulation, (sometimes called 2.5D) is useful for disk antenna modeling, accurate scattering modeling, Gaussian laser beam models, and cavity model analysis for accelerators.

A volumetric external current density can now be used with Electromagnetic Waves by using a new volumetric current option for domains.

View Screenshot
The radiation pattern from a microstrip patch antenna

Two-Arm Helical Antenna example tutorial from the Model Library of the RF Module.

Helical and Spiral Slot Antennas Models

Two new tutorials are available in the Model Library of the RF Module: Two-Arm Helical Antenna and Spiral Slot Antenna. The RF Module now comes with 63 tutorials with model files and step-by-step PDF documentation.

The Two-Arm Helical Antenna tutorial shows an analysis of the normal and axial modes. The Spiral Slot Antenna tutorial shows how to build a spiral geometry using parametric curves, and computes S-parameters and far-field patterns.

The radiation pattern from a microstrip patch antenna

Spiral Slot Antenna example tutorial from the Model Library of the RF Module.

Tunable Evanescent Mode Cavity Filter Using a Piezo Actuator

In this new tutorial model, an evanescent mode cavity filter is realized by adding a structure inside of the cavity. This structure changes the resonant frequency below that of the dominant mode of the unfilled cavity. A piezo actuator is used to control the size of a small air gap which provides the tunability of the resonant frequency. In addition to the RF Module, this model requires one of the following: the Acoustics Module, the MEMS Module, or the Structural Mechanics Module.

MEMS Module


The MEMS Module comes with a new Thermoelasticity user interface for thermoelastic damping of resonant MEMS devices. When an elastic rod is stretched reversibly and adiabatically, thermodynamics will tell us that its temperature drops. The theory of thermoelasticity describes this phenomenon, together with the irreversible processes that occur in a vibrating rod. When a structure vibrates in a mode with both local compression and expansion there are always some losses associated with the irreversible heat conduction between the expanding areas that cool and the contracting areas that heat. These losses result in thermoelastic damping, which is covered by this new user interface.

Thin-Film Flow Updates

The Thin-Film Flow user interface and underlying functionality has been revised. The user interfaces have been improved with easier-to-understand terminology. A new Reynolds Equation boundary condition has been added for Solid Mechanics, and two new benchmark models are available.

View Screenshot
Thermoelastic damping
Thermoelastic damping is an important factor when designing MEMS resonators. The cyclic deformation of the resonator creates local temperature variations and thermal expansion of the material, which appears as damping. This tutorial shows including thermoelastic damping effects in a MEMS resonator with the new Thermoelasticity user interface in the MEMS Module.
Plasma Module

Finite Volume Discretization

Finite volume discretization is now available for the DC Discharge and Capacitively Coupled Plasma user interfaces. This option is available in the Advanced Properties section and is available for certain boundary conditions. Boundary conditions not compatible with this option are Terminal, Distributed Capacitance, Thin Low Permettivity gap, and Floating potential.

View Screenshot

Plasma Display Panel

A new model of a plasma display panel is based on the new finite volume discretization. The model illustrates the physics of a dielectric barrier discharge which leads to generation of light in pixels used for plasma display panels. The electric potential after 50 ns is shown in the picture.

Corona Discharge

A new 1D model of an atmospheric pressure corona discharge is based on the new finite volume discretization. The model simulates a negative corona discharge occurring in between two coaxially fashioned conductors. The negative electric potential is applied to the inner conductor and the exterior conductor is grounded. The modeled discharge is simulated in argon at atmospheric pressure.

View Screenshot

Quick Options for Circuits

An updated Electric Potential feature is available for the DC Discharge and Capacitively Coupled Plasma user interfaces. There are quick choices for the most common external circuits: Series RC circuit, Ballast resistor, Blocking capacitor. The DC Glow Discharge example model showcases this new functionality.

View Screenshot

Dielectric Barrier Discharge

A new Dielectric Barrier Discharge Plasma Actuator model illustrates the new finite volume discretization scheme available in the Plasma Module. In this model, the exposed electrode is supplied with a transient voltage that, at its peak, causes the gas over the inserted electrode to ionize. The ionized gas, in the presence of the electric field produced by the electrode geometry, results in a body force vector that acts on the ambient (neutrally charged) gas. The body force created by the space charge distribution is the main mechanism used for active aerodynamic control. The visualizations show the electric potential at different snapshots in time.

Structural Mechanics Module

Membrane Load Cases and Initial Stress-Strain Harmonic Perturbations

The harmonic perturbation mechanism available in the Structural Mechanics Module, as well as in the MEMS Module, allows you to perform eigenmode and frequency-domain analysis on prestressed structures. In all structural mechanics user interfaces, it is now possible to give a harmonic perturbation to initial stresses and strains.

Load and constraint groups, for controlling load cases, are now supported also by the Membrane user interface.

View Screenshot
A Campbell diagram for the six lowest modes of rotating blade. In this benchmark model, available in the Structural Mechanics Module, the eigenfrequencies of a rotating blade are studied. The model shows how stress stiffening and the combined effect from stress stiffening and spin softening affects the fundamental eigenfrequency.
Nonlinear Structural Materials Module

New Hyperelastic Material Models

The Nonlinear Structural Materials Module comes with three new hyperelastic material models: Yeoh and Varga for nearly incompressible nonlinear elastic materials such as rubber, and Blatz-Ko for highly compressible materials such as foam rubber.

View Screenshot
Nonlinear Structural Materials Module analyzes inflation of a Spherical Rubber Balloon
This tutorial from the Nonlinear Structural Materials Module analyzes inflation of a Spherical Rubber Balloon for four different hyperelastic material models: Neo-Hookean, Mooney-Rivlin, Ogden, and Varga.
Geomechanics Module

Dilation Angle for Soil Plasticity

For soil plasticity, a new option to use dilatation angle in the plastic potential is available for the Drucker-Prager and Mohr-Coulomb plasticity models. Using this option, the dilatation angle replaces the angle of internal friction when defining the plastic potential.

View Screenshot
Geomechanics Module
Concrete structures almost always contain reinforcements in the shape of steel bars ("rebars"). In COMSOL, individual rebars can be modeled by adding a Truss interface to the Solid Mechanics user interface used for the concrete. The solid mesh for the concrete and the rebar mesh can be independent, because the displacements are mapped from within the solids onto the rebar at a certain position. The picture is from the Concrete Beam example tutorial in the Geomechanics Module.
Acoustics Module

New Acoustics Examples

A new example model of the Brüel & Kjær® 4134 condenser microphone compares the simulated sensitivity level to measurements performed on an actual microphone. The results are in good agreement. The membrane deformation, pressure, velocity, and electric field are also computed.

Acoustics Module
A simulation of the Brüel & Kjær 4134 condenser microphone. Model geometry and measurement courtesy of Brüel & Kjær Sound & Vibration Measurement A/S, Nærum, Denmark.

A time-dependent simulation of a probe tube microphone includes an external acoustic domain, the probe tube, and the cavity in front of the microphone diaphragm. The probe tube is modeled using the Pipe Acoustics, Transient user interface and is connected to two different pressure acoustics domains. The model requires both the Acoustics Module and the Pipe Flow Module.

For nonlinear acoustics, an example is now available that demonstrates how to model transient nonlinear propagation of finite-amplitude acoustic waves in fluids, solving a 1D Westervelt equation.

A new tutorial showcases a spherical piezoacoustic transducer. The device is poled along the radial direction of the sphere, demonstrating setting up of a local coordinate system.

An updated model demonstrates acoustics of a particulate-filter-like system. This example computes the acoustic transmission loss through a particulate-filter-like system using the Poroelastic Waves user interface.

Equivalent Fluid Model News

A new equivalent fluid model called Boundary layer approximation is available for pressure acoustics. Use it for modeling thermal and viscous losses at the boundaries of a duct as a bulk loss. You can choose between wide duct and narrow duct approximations.

For the Biot equivalent fluid models you can now enter the viscous characteristic length or viscous characteristic length parameter directly in the equivalent fluid models.

View Screenshot

Thermoacoustics Heat Source

A domain heat source option is now available in the Thermoacoustics user interface. Adding a heat source to a domain is useful when modeling photoacoustics and acoustic heat exchangers.

Rigid Connectors, Truss, Kinetic Energy, and More
A photoacoustic resonator and the new heat source setting for thermoacoustics.
Acoustics Module
This model shows how to model transient nonlinear propagation of finite-amplitude acoustic waves in fluids using the Acoustics Module. A nonlinear term is added to the linear wave equation, which makes the problem identical to solving a 2nd-order Westervelt equation. The Fourier spectra of the computed numerical solution are compared to an analytical solution.
CFD Module and Fluid Flow Features

New Default Solvers for CFD

A revised default solver mechanism for CFD is available for all fluid flow user interfaces. It comes with reduced memory requirements for large models and offers more automation and less manual tuning. The default geometric multigrid (GMG) solver is now automatically adjusted based on the number of mesh elements. The mesh-building is triggered when retrieving the default solvers. A direct solver is used for smaller models, where small is defined as 100,000 elements in 3D and 300,000 elements in 2D. Additional multigrid levels are automatically added for large models. The first additional level is added at 600,000 elements in 3D. A maximum of 4 levels including the finest mesh is available for first-order elements. Additional levels are added when used with higher-order elements. These improvements will be noticeable when using any of the fluid flow user interfaces of COMSOL Multiphysics and add-on modules.

mems Module
This simulation examines the performance of a displacement ventilation system. The flow is modeled using Non-Isothermal Turbulent Flow with a k-omega turbulence model.

More Robust and Easier-to-use Solver for Stationary CFD and Fluid-Structure Interaction

Pseudo-time stepping is a method used for robust convergence towards a steady-state solution for fluid flow. The new pseudo-time stepping method is available for all stationary flow physics user interfaces as well as for fluid-structure interaction.

It is faster for simple models and more roboust for large models. The CFL number is now controlled by a PID regulator instead of a built-in expression which makes the solver settings much easier to adjust. These improvements will be noticeable when using any of the fluid flow user interfaces of COMSOL Multiphysics and add-on modules.

View Screenshot

Reacting Flow

A Reacting Flow user interface for Laminar and Turbulent Mass Transport is now available in the CFD Module. It is a combination of laminar or turbulent single-phase flow with transport of concentrated species and includes turbulent wall functions for mass transport, turbulent reaction modeling, and reaction kinetics. Turbulent reaction modeling is based on the so-called eddy dissipation concept (EDC). Two built-in algebraic models, Kays-Crawford and High-Schmidt number, automatically compute the Schmidt number.

View Screenshot

One-Way Coupled Fluid-Structure Interaction (FSI)

Two new study types for FSI are available: Stationary, One-way Coupled and Time-dependent, One-way Coupled. These study types first solve for the fluid flow and then for the elastic solid. Other physics can be included in either or both study steps. Previously, two-way coupled FSI was available. Solving for One-way Coupled FSI can be more efficient when there is no coupling from the solid back on the fluid - that is, no momentum transfer from the structure ”flexing back” on the fluid. The FSI options require one of the Structural Mechanics or MEMS Modules. More advanced fluid flow options are available with one of the CFD or the Heat Transfer Modules.

View Screenshot
Heat Transfer Module

Moist Air and Condensation

The Heat Transfer Module now has an added Moist air fluid type for Heat Transfer in Fluids, Conjugate Heat Transfer, and Non-Isothermal Flow. This new option includes thermodynamic properties of unsaturated humid air and adds dedicated postprocessing variables for verifying if the saturation limit has been reached and there is risk of condensation. A typical application would be to avoid water formation in a flow channel for preventing corrosion.

View Screenshot

Load Cases for Heat Transfer

Load cases for heat transfer are now available using the same load and constraint group concept as previously available for structural mechanics. Load groups are used for defining sets of heat sources and heat fluxes. Constraint groups are used for fixed temperature conditions. Load cases with load and constraint groups are available for all heat transfer user interfaces.

View Screenshot
Heat Transfer Module
A new condensation indicator variable is used to visualize locations where there is increased risk of condensation. In this simulation of a flow channel with a heat sink and a cold plate, the saturation limit is reached close to the cold plate.
Microfluidics Module

New Benchmark Examples

A new benchmark example computes the radial pressure distribution and flow rate through a rotating Lab-on-a-Chip (LOAC) platform. The flow through the device is a result of centrifugal and Coriolis forces. The results compare well with the referenced publication. Centrifugal and Coriolis forces are easily added as user-defined volume forces by typing expressions in terms of density, angular velocity, fluid velocity, and radial distance.

Heat Transfer Module
A split and recombine micromixer channel showing mixing of a tracer fluid by multi-lamination. Higher-order finite elements are used for accurately capturing the sharp diffusion interfaces.


A second benchmark example of a split and recombine mixer channel shows a tracer fluid that is introduced and mixed by multi-lamination. Diffusion is removed from the model using an extremely low diffusion coefficient so that any numerical diffusion can be studied in the lamination interfaces. The results compare well with the referenced publication in both the lamination patterns and total pressure drop across the mixer.

Rotating streamlines for a Lab-Ob-A-Chip
Streamlines visualized in a rotating Lab-On-A-Chip (LOAC) platform. Both centrifugal and Coriolis forces are accounted for. These effects are very easy to introduce as user-defined volume forces.
Pipe Flow Module

SCCM Inflow, Internal Constraints, and Y-Junctions

The inflow condition for Pipe Flow now has a SCCM (standard cubic centimeter per minute) option. This makes it possible to specify a normal-volume based flow.

Internal temperature and pressure constraints can now be set. This is needed for circulating flow and other configurations.

The previously available T-junction option now also supports Y-junctions.

Chemical Reaction Engineering Module

Reacting Flow and User-defined Reaction and Species Settings

The Chemical Reaction Engineering Module includes a new laminar Reacting Flow user interface. It is a combination single-phase flow with transport of concentrated species and offers a reaction feature and pseudo-time stepping for both the species and the momentum equations. The CFD Module offers an extended turbulent version of the Reacting Flow user interface.

Several input fields in the Reaction and Species nodes in the Reaction Engineering user interface have been equipped with a new Automatic/User Defined option. In addition, the User Defined option comes equipped with a Reset to Default button in order to generate the default automatically available expression, which can then be manually edited.

View Screenshot
Chemical Reaction Engineering Module
One of the tutorials of the Chemical Reaction Engineering Module, Isoelectric Separation, simulates a separation process in which an electric field divides a stream containing six different ionic species into pure component streams.
Batteries & Fuel Cells Module

Capacity Fade in a Lithium-Ion Battery and Solid Electrolyte Interface (SEI) Layer

The Capacity Fade in a Lithium-Ion Battery tutorial has been updated with an SEI layer computation. This 1D model demonstrates how to use the Events interface to simulate battery capacity loss during cycling. The battery is switched between constant voltage and constant current operation, both during charge and discharge. Cycleable lithium is lost and the resistance of the SEI layer increases in the negative electrode due to a parasitic lithium/solvent reduction reaction.

Capacity Fade of a Li-ion Battery
The SEI layer potential drop of a lithium-ion battery simulation is plotted for 10 cycles.

Average Solid Particle Concentration

For porous electrodes in the Lithium-Ion Battery user interface, a new liion.cs_average variable has been introduced. The variable represents the average solid particle concentration in the electrode particles. Similarly a variable batbe.cs_average is available for the Battery with Binary Electrolyte user interface.

View Screenshot

Separator Domains

For the Tertiary Current Distribution, Nernst-Planck user interface, you can now add a Separator domain node to model electrolyte charge and mass transport in an electronically isolating porous matrix.

View Screenshot

Film Resistance

For resistance modeling in electrochemistry due to passivation and growing oxide layers, a new Film Resistance modeling option is available. If a resistive film forms on the interface between an electrode and an electrolyte, this will result in additional potential losses. Film Resistance is introduced for all boundary conditions that model an interface between an electrolyte and an electrode.

View Screenshot
Electrodeposition Module

Fountain Flow Effects on a Rotating Wafer

This new modeling example explores the convective flow effects in a cell with a rotating wafer. Electrolyte enters the cell from the bottom and flows towards the rotating wafer where copper is deposited. The laminar swirl-flow profile, the concentration of copper, the electrolyte potential, and the electric potential of the thin wafer are computed. The geometry is represented in two dimensions with axial symmetry. This model requires both the Electrodeposition Module and the CFD Module.

Film Resistance

For resistance modeling in electrochemistry due to passivation and growing oxide layers, a new Film Resistance modeling option is available. If a resistive film forms on the interface between an electrode and an electrolyte, this will result in additional potential losses. Film Resistance is introduced for all boundary conditions that model an interface between an electrolyte and an electrode.

View Screenshot
Corrosion Module

Crevice Corrosion, Corrosion Protection of an Oil Platform, Galvanized Nail, and Diffuse Double Layer Examples

Five new tutorial models are available in the Corrosion Module:

A new model exemplifies the basic principles of crevice corrosion and how a time-dependent study can be used to simulate the electrode deformation.

A second example of crevice corrosion models corrosion of iron in a buffer solution of pH 4.8, formed by equal amounts of acetic acid and sodium acetate. The model combines electrochemical dissolution of iron on the crevice walls together with heterogenous equilibrium reactions in the electrolyte.

A new corrosion protection tutorial shows primary current distribution of a corrosion protection system of an oil platform using sacrificial aluminum anodes.

A new 1D verification model of a diffuse double layer shows how to couple Poisson's equation for the potential to the Nernst-Planck equations for ion transport in order to model the diffuse double layers, without charge neutrality, in a cell with a binary (1:1) electrolyte.

A new example model of a galvanized nail shows how to first set up a galvanic corrosion cell to model a stationary secondary current distribution problem, and then how to expand the model by adding mass transfer to model a tertiary current distribution.

Subsurface Flow Module
A galvanic corrosion simulation of a galvanized nail.

Film Resistance

For resistance modeling in electrochemistry due to passivation and growing oxide layers, a new Film Resistance modeling option is available. If a resistive film forms on the interface between an electrode and an electrolyte, this will result in additional potential losses. Film Resistance is introduced for all boundary conditions that model an interface between an electrolyte and an electrode.

View Screenshot
Further Reading