COMSOL 4.2 Release Highlights

Released May 18, 2011

COMSOL Multiphysics 4.2 represents a significant expansion of the software’s applications, features, and functionality. Version 4.2 empowers current users to do more with their simulation environments, while new industries will now be able to leverage the innovation of multiphysics simulation. With this release, COMSOL continues to deliver on its promise to supply the science and engineering markets with the state-of-the-art simulation products for an expanding set of applications.

Table of Contents
New Products

Geomechanics Module

The Geomechanics Module is a specialized add-on to the Structural Mechanics Module for simulation of geotechnical applications such as tunnels, excavations, slope stability, and retaining structures. The Module features tailored interfaces to study plasticity, deformation, and failure of soils and rocks, as well as their interaction with concrete and human-made structures.

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Geomechanics Module
Simulations of a retaining wall (left), a tunnel excavation (middle) and a flexible footing (right) using the Geomechanics Module

LiveLink™ for AutoCAD®

With the new LiveLink for AutoCAD interface you can transfer a 3D geometry from AutoCAD to COMSOL Multiphysics. The synchronized geometry in the COMSOL model stays associative with the geometry in AutoCAD. This means that settings applied to the geometry, like physics or mesh settings, are retained after subsequent synchronizations. The LiveLink interface is also bidirectional to allow you to initiate a change of the AutoCAD geometry from the COMSOL model.

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Electrodeposition Module

The Electrodeposition Module brings the power of COMSOL Multiphysics to electrochemical processes for such diverse applications as chrome plating in automotive industry, e-coating, electro-coloring, decorative electroplating, and electrodeposition for PCB manufacturing.

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Microfluidics Module

The Microfluidics Module brings easy-to-use tools for the study of microfluidic devices and rarefied gas flows. Important applications include simulations of lab-on-a-chip devices, digital microfluidics, electrokinetic and magnetokinetic devices, inkjets, and vacuum systems.

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Microfluidics Module
Simulations of an electrowetting lens (left) and molecular flow (right) using the Microfluidics Module.
LiveLink for SolidWorks

One-Window Interface

LiveLink for SolidWorks has been extended with a One Window Interface where a SolidWorks user can stay inside of the SolidWorks environment and work synchronously with COMSOL Multiphysics.

Mesh and Geometry

Coordinate-Based Selections

When analyzing multiple slightly modified versions of the same part, Coordinate-Based Selections provide a quick way of repeating a simulation without having to change any material settings, boundary conditions or mesh parameters. Coordinate-Based Selections can be parameterized in the same way as geometry objects.

Coordinate-Based Selections
In the picture, a bracket
assembly is analyzed:
first with eight mounting
bolts and then with twelve mounting bolts. A coordinate-box selection is used to select all objects within the box and to apply fixed constraints to the eight mounting bolts. In the next step, four mounting bolts have been added and the coordinate-box selection automatically applies the fixed constraints.

Cap Faces

The Cap Faces geometry operation makes it easy to cover the ends of fluid channels and subsequently mesh the interior of imported CAD parts. Just select the edges that trace out the surface to be formed. This operation makes for a quicker and easier transition from a purely mechanical model to a fluid or fluid-structure interaction (FSI) model. This feature requires the CAD Import Module or one of the CAD LiveLink products.

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Meshing using Virtual Geometry Operations

New Virtual Geometry tools allow for modification of CAD models without changing the underlying surface curvature. By applying the Form Composite Faces operation, a much more useful mesh is produced that accurately represents the surface shape without adding too many elements. COMSOL Multiphysics is furthermore capable of using higher-order elements to represent curved surfaces during analysis.

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Parametric Surfaces

The new Parametric Surfaces feature allows for creation of surfaces based on analytical expressions or look-up table data. You can tune the resolution of the underlying NURBS surface to enable a more detailed surface representation and finer mesh when called upon.

Parametric Surfaces
The picture shows a flow simulation where imported elevation data was used to represent the gap of a rock fracture.
Studies and Solvers

Time-Dependent Adaptive Mesh Refinement

Two-phase flow simulations can now be solved more efficiently with a new time-dependent adaptive mesh refinement algorithm. In addition to two-phase flow, time-dependent adaptive meshing is available for any time-dependent simulations.

Time-Dependent Adaptive Mesh Refinement
The picture shows an inkjet model from the Model Library of the Microfluidics Module (also available in the CFD Module). The adaptive mesher automatically identifies the need for a denser mesh at the phase boundary between air and ink and dynamically updates throughout the transient simulation.

Automatic Remeshing for Moving Meshes

For a simulation that includes a moving mesh, a new automatic remeshing feature makes more extreme deformation states possible. When the mesh is deformed beyond a user-defined mesh quality threshold, the automatic remeshing activates, and the simulation is automatically continued, starting from the new mesh.

Physics Selection in Study Steps

A new Physics Selection utility makes it easy to activate or deactivate select Physics Interfaces during the modeling process. You can use this to control which physics should be considered for a particular study step.

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Convergence Plot for Solvers

Convergence plots are now available for monitoring convergence of nonlinear, iterative, and time-dependent solvers. For nonlinear simulations, separate convergence plots show the convergence of the nonlinear iterations and the core linear algebra solver iterations.

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Fast Parallelized Assembly and Solvers

The COMSOL Multiphysics direct solvers have been multicore and cluster-enabled for several years. With Version 4.2, the multiphysics assembly algorithms and iterative solvers are also parallelized which brings faster and more memory efficient computations for a wide range of applications on virtually any type of computer platform from laptop to cluster.

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Microfluidics Module
The picture shows the squeezed elements generated by a moving boundary and the resulting elements directly after an automatic remesh. The model is available in the Electrodeposition Module Model Library.
Results and Visualization

Report Generator

The new Report Generator generates HTML reports of models. The Report Generator is an integrated part of the model, and you can add several reports to a model. A report includes a table of contents with clickable links to the contents below. The Report Generator uses a built-in Style Sheet, but you can use a custom Style Sheet to change the appearance of the report in a web browser.

Nyquist Plots

A Nyquist plot shows the magnitude and phase of a frequency-response simulation result. This type of plot shows the magnitude as the distance from the origin and the phase as the angle using a curve with the frequency as the parameter. Nyquist plots have important applications for users of the AC/DC, RF, Structural Mechanics, Acoustics, MEMS, and Batteries & Fuel Cells Modules.

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Streamline Ribbon Plot

Streamlines can now be visualized using ribbon plots where the width and color of the ribbons can be controlled by an arbitrary expression. The pictures show two different ribbon plots for a turbulent flow simulation.

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Adjustable Position of Color Legends

You can now position the color legends to the right, to the left, above, below, or on alternating sides of the plot.

Variable Aspect-Ratio Visualization

High aspect-ratio models can now easily be visualized also in a non-aspect-ratio preserving mode.

Microfluidics Module
The picture shows a thermal actuator using actual aspect-ratio (left) and with Preserve aspect ratio turned off (right).
Microfluidics Module
The Report Generator

Improved 2D Renderer

The new, faster 2D renderer comes with improved axis labels, easier selection of overlapping pair boundaries, and a new drawing table with grid and rulers that show the position of the pointer.

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Histogram Plots

Histogram plots, available in Results, is used to show the distribution of data throughout volumes, surfaces, edges, or points in a model. You can control bins based on number of bins or data limits. Plots can be continuous or discrete and data normalization options include Neutral, Peak, or Integral.

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RMS and Variance of Data Series

For Derived Values, you can apply an operation such as the integral or maximum of the averaged quantity for the data series. For example, you can immediately display the integral or maximum of the averaged quantity for each step in the data series. Additional operations made available with Version 4.2 are RMS (the root mean square or quadratic mean) and Variance.

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Default Plots

In the Results node of the Model Builder tree, new default plots are now adapted to the physics in the model with descriptive names of the created plot groups.

Mathematical Interfaces

New PDE and ODE Interfaces

The interfaces for partial differential equations (PDEs) are extended with an additional set of templates for equations defined on surfaces and edges. Applications include using the new Coefficient Form Boundary PDE interface for surface diffusion, accumulation of material on boundaries, and equation-based shell modeling for any type of physics.

A new set of interfaces are available for spatially distributed ordinary differential equations (ODEs) and differential algebraic equations (DAEs). Applications include material-memory simulations, such as bioheating damage computations or material creep, where the material state is represented with a unique state-variable at each point in the computational volume.

The Classical PDE interfaces now include templates for the Heat Equation and the Convection-Diffusion Equation.

All PDE, ODE, and DAE interface templates can be used freely in multiphysics combinations with any application-specific modules.

Material Library Tools

Material Rendering

Materials are now rendered using color, texture, and reflectance. Gold, copper, air, water, concrete, and some other common materials have their own specific material appearance properties. A material’s appearance can be customized and includes separate settings for specular, diffusive, and ambient colors as well as texture noise levels. To enable texture rendering, set the Visualization preferences to be Optimized for Quality.

General COMSOL Desktop Functionality

Drag-and-Drop in the Model Builder Tree

Drag-and-drop is now supported in the Model Builder tree. Using this feature, you can change the order of existing nodes or copy or duplicate nodes.

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Updated Progress and Log Windows

Progress and Log information is now available in separate windows. The Progress window features Auto-clearing. The Log window supports Clear and Lock as well as Resume scroll. There is now an extra log divider with model name when opening a new model.

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AC/DC Module

Small-signal Analysis

Small-signal analysis is now generally available for all modules, including the AC/DC Module.

Small-signal Analysis
The picture shows a typical application: an inductor with a nonlinear magnetic core and an inductance that changes with increased current. The variable inductance is also known as the small-signal, or differential, inductance.

Lumped Ports for AC/DC Analysis

A Lumped Port boundary feature is now available in the Magnetic Fields interface and in the Magnetic and Electric Fields interface. This feature is used for easier excitation of coils and other conducting structures. It also gives access to S-parameters.

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Acoustics Module

Acoustic-Piezoelectric Interaction

A new multiphysics interface for Acoustic-Piezoelectric coupling makes piezo-acoustics functionality easier to use. Analyses are available for frequency domain and time domain studies and combine features from the Pressure Acoustics, Solid Mechanics, Electrostatics, and Piezoelectric Devices interfaces.

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Acoustic-Shell Interaction

A new multiphysics interface for Acoustic-Shell Interaction enables modeling of vibrating thin elastic structures and their induced sound pressure field. The coupling is bidirectional and is available for frequency domain and the time domain studies in 3D. The Acoustic-Shell Interaction interfaces combine features from the Pressure Acoustics and Shell interfaces of the Acoustics Module and the Structural Mechanics Module, respectively.

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Elastic and Poroelastic Waves

The Acoustics Module features two new interfaces for waves in solid and porous media. The Elastic Waves interface, for general elastic solids, can be combined with a new Poroelastic Waves interface for frequency-domain analysis of poroelastic wave propagation.

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The Acoustics Module features new dedicated modeling tools for thermoviscous acoustics that enable highly accurate simulation of miniaturized speakers and microphones in handheld devices.

The need for thermoacoustics emerges whenever the dimensions of an acoustic device become small compared to the viscous and thermal boundary layers.

Thermoacoustic wave-field and damped Helmholtz resonator
The picture to the right shows an acoustic coupler with a damped Helmholtz resonator. The model includes thermal conduction and viscous losses.
The picture to the left shows the thermoacoustic wave-field in a shallow uniform waveguide with results matched to an analytical solution.
Batteries & Fuel Cells Module

Batteries & Fuel Cells Module

The Batteries & Fuel Cells Module features a new AC Impedance Study type for simulating Electrochemical Impedance Spectroscopy (EIS). A new Surface Reactions interface enables modeling of surface reactions on boundary surfaces. A Material Library comes with common battery electrode materials and electrolytes.

Batteries & Fuel Cells Module
The picture shows the Temperature field in the cooling channels and the batteries in a battery pack for automotive applications. The model includes a high-fidelity electrochemical model of the batteries coupled to a thermal analysis for the batteries and the components in the battery pack, and the fluid flow in the cooling channels.

New Tutorials

  • Edge Effects In a Spirally Wound Li-Ion Battery
  • Thermal Modeling of a Cylindrical Li-Ion Battery in 2D
  • Thermal Modeling of a Cylindrical Li-Ion Battery in 3D (additionally requires the Heat Transfer Module)
  • Electrochemical Impedance Spectroscopy in a Fuel Cell
  • Primary Current Distribution in a Lead-Acid Battery Grid Electrode
  • Soluble Lead-Acid Redox Flow Battery
CFD Module

High-Mach Number Fluid Flow

The new High-Mach Number Fluid Flow interface applies when the flow velocity is large enough to introduce significant changes in the density and temperature of the fluid; the thermodynamic properties of the fluid are coupled. Appreciable changes in the fluid properties are encountered as the flow velocity approaches, or exceeds, the speed sound. As a rule of thumb, velocities greater than 0.3 times the speed of sound are considered to be high Mach number flows. Important applications include: nozzles, pipe networks, valves, and aerodynamic phenomena.

High-Mach Number Fluid Flow
The picture shows a benchmark model for turbulent compressible flow in a two-dimensional converging-diverging diffuser (Sajben diffuser). The flow enters the diffuser at a velocity of Ma = 0.46, accelerates through the converging part, and reaches supersonic conditions at the throat of the diffuser. The supersonic flow is terminated with a shock in the diverging part, after which the flow is subsonically decelerated.
Chemical Reaction Engineering Module

Reacting Flow

A new physics interface for Reacting Flow, Diluted Species, makes coupled mass and momentum transport in free and porous media available from one single user interface. A similar physics interface for Concentrated Species is also available. The model coupling for the velocity field and mixture density is set up automatically. In addition, the effective transport coefficients in a porous matrix domain can be derived based on the corresponding values in for a non-porous domain.

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Infinite Elements for Diffusion

COMSOL Multiphysics Version 4.2 introduces a new way of defining Infinite Elements for simulation of unbounded regions. Since different physics can share the same Infinite Elements, you can now define Infinite Elements in the Model Definitions node, eliminating redundant action on each Physics Interface.

The interface for Transport of Diluted Species now provides Infinite Elements for diffusion simulations using the new mechanism. The picture shows the new Model Builder tree node.

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Parameter Estimation in Chemical Reaction Models

By combining the Chemical Reaction Engineering with the Optimization Modules, you can use a new Parameter Estimation feature for predefined reactor types in the Reaction Engineering interface.

Surface Reactions

A new Surface Reactions interface is used for reactions involving surface adsorbed species and species in the bulk of a reacting surface. The interface is applied to the boundary of a model and is coupled to a mass transport interface in the adjacent bulk domain. The Surface Reactions interface can be used together with the Chemical Species Transport, Reacting Flow, and the Electrochemistry interfaces. Predefined expressions for the growth velocity of the reacting surface makes it easy to set up models with moving boundaries.

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Parameter Estimation in Chemical Reaction Models
The picture shows a tutorial model for finding the Arrhenius parameters of a first-order reaction where Benzene diazonium chloride decomposes to benzene, chloride, and nitrogen.
Heat Transfer Module

Thermal Wall Functions with Radiation

Thermal wall functions with turbulence now support the Surface-to-Surface Radiation and Highly Conductive Layer features. This enables very sophisticated thermal simulations: including any combination of turbulent flow, heat transfer in fluids, heat transfer in solids, heat radiation, and thin thermally high-conducting layers such as metal sheets.

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Heat Transfer in Multilayered Structures

For heat transfer in thin layers, a new multilayer option of the Thin Thermally Resistive Layer makes it possible to quickly model thin structures with multiple layers of different conductivity.

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Fan and Grill Boundary Conditions

Electronic cooling simulations are made easier by the new Fan and Grill boundary conditions. A new Fan boundary condition is also available on interior boundaries, called a slit condition. Fan curves can be entered, or loaded from file, in table format for use at inlets in flow models.

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Thermal Light Color Table

A new default Color Table (color scale) named Thermal Light is optimized for visualization of heat transfer simulations. The color range is truncated at the lower end and eliminates the darkest shades of red.

Thermal Light Color Table
Plasma Module

Surface Reactions for Plasmas

New tools are available for modeling surface reactions and species.

The picture shows the accumulated height of Silicon deposited on the wafer surface as a function of time. The model verifies that the total mass in the system is conserved. The principle can be applied to study processes like chemical vapor deposition (CVD) and plasma enhanced vapor deposition (PECVD).

RF Module

Far-Field in a Medium (RF) and New Models

For computing radiation patterns from antennas and radiating components, far-field evaluation is an essential tool. The far-field feature has been extended and now supports computing the far field in a medium other than vacuum. It has changed from being a boundary feature to being a domain feature with a domain selection and a boundary selection.

Far-Field in a Medium (RF) and New Models
The picture to the right shows a model of a plane wave 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. This analysis is made possible by a new port boundary condition for Floquet-type periodic boundary conditions.
The picture to the left shows a new tutorial models for impedance matching of a lossy anisotropic ferrite 3-port circulator.
New Structural Mechanics Features

Piezoelectric PMLs

New Piezoelectric Perfectly Matched Layers (PMLs) are capable of simultaneously absorbing the elastic and electric components of an outwards traveling piezoelastic wave. This feature is important for modeling piezo transducers and acoustic wave filters such as BAW and SAW. The functionality is available in the Structural Mechanics Module, MEMS Module, and Acoustics Module.

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Infinite Elements for Solid Mechanics

For Solid Mechanics, certain modeling tasks require the computation of stress and strain for a large slab of material. For practical reasons such models are artificially truncated close to a region of interest and the analyst then faces the problem of what boundary conditions to apply to the truncated domain boundaries. Modeling with Infinite Elements avoids this problem entirely by automatically scaling the computational domain to infinity. The Structural Mechanics and the MEMS Modules offer Infinite Elements as a new feature under the Model Definitions node in the Model Builder tree.

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Springs and Dampers

For simulating non-rigid boundaries, new boundary conditions for springs and dampers have been added for points, edges, boundaries, and domains. This functionality is available for all interfaces in the Structural Mechanics Module and for the Solid Mechanics interfaces in the Acoustics and MEMS Modules. Similarly, a new Thin Elastic Layers boundary condition is available on interior boundaries and between pairs in assemblies.

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Beam Cross-Section Library with
Common Sections

The Structural Mechanics Module now features a tool for automatic computation of beam cross-section properties for a number of common cross sections when using the Beam interface.

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Prestressed Analysis

The Structural Mechanics, MEMS , and Acoustics Modules offer new powerful and easy-to use tools for prestressed analysis of eigenmode and frequency-response. Structures modeled with the Solid Mechanics interface can be prestressed by mechanical, thermal, or arbitrary multiphysics-based loads.

Prestressed Analysis
The picture shows one of the tutorial models in the Model Library of the Structural Mechanics Module, which compares the frequency response of an unloaded case with that of a prestressed case.

Added Mass

Added mass can now be specified for edges, boundaries, and domains for all interfaces in the Structural Mechanics Module and for the Solid Mechanics interfaces in the Acoustics and MEMS Modules. Important applications are: modeling non-structural added mass for a vibrating structure immersed in a fluid, adding mass from thin layers that are not contributing to the structure's stiffness, correcting for mass changes due to CAD defeaturing, or including mass from components that are not represented by any geometry in the model.

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Subsurface Flow Module

Subsurface Flow Module

The Subsurface Flow Module (previously named the Earth Science Module) benefits from many of the new features of Version 4.2.

Combining the new Geomechanics Module with the Subsurface Flow Module enables new geotechnical multiphysics combinations such as elastoplastic soil models with poroelasticity as well as rock material models with solute transport.

Thin Diffusion Barrier Boundary Condition

A new Thin Diffusion Barrier boundary condition for interior boundaries in the Solute Transport interface enables modeling of thin layers of much thinner diffusion coefficient than that of adjacent domains.

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Further Reading