*Released May 17th, 2012*

COMSOL Multiphysics version 4.3 establishes COMSOL as the leading innovator in multiphysics simulation for electrical, mechanical, fluid, and chemical applications.

### Major news in version 4.3

Turbulent mixing

Turbulent mixing is now available in the CFD Module for mass transport simulations.

- New Products
- Mesh and Geometry
- Studies and Solvers
- Results and Visualization
- COMSOL Desktop
- CAD Import Module and LiveLink Products

- AC/DC Module
- RF Module
- Structural Mechanics Module
- Geomechanics Module
- Acoustics Module
- MEMS Module
- CFD Module
- Heat Transfer Module
- Plasma Module

- Microfluidics Module
- Subsurface Flow Module
- Particle Tracing Module
- Batteries & Fuel Cells Module
- Chemical Reaction Engineering Module
- Electrodeposition Module
- Optimization Module
- Further Reading

### Pipe Flow Module

The Pipe Flow Module is used for simulations of fluid flow, heat and mass transfer, hydraulic transients, and acoustics in pipe and channel networks. Pipe flow simulations yield the velocity, pressure variation, and temperature along the pipes and channels. The module is suitable for pipes and channels which have lengths large enough so that flow in them can be considered to be fully developed and represented by a 1D approximation.

The module can be used to design and optimize complex cooling systems in turbines, ventilation systems in buildings, pipe systems in chemical processes, and pipelines in the oil, gas and mining industry. User interfaces for piping components such as bends, valves, T-junctions, contractions/expansions and pumps are available. Interfaces for water hammer simulations and pipe acoustics are also included.

Learn more### Corrosion Module

The Corrosion Module empowers engineers to simulate the electrochemistry of corrosion and corrosion protection of metal structures. Models in 1D, 2D, and 3D are set up to include the relevant corrosion and other reactions within the electrolyte and at the metal surface interface using a series of predefined user interfaces. These are solved while considering the transport of ions and neutral species in the solution, the current conduction in the metal structure, and other phenomena such as fluid flow and heat transfer.

Simulations using the Corrosion Module can be used to understand and avoid corrosion situations, as well as to design and optimize corrosion protection. This can be done at the microscopic scales, such as in crevice and pitting corrosion where the localized concentrations can be significant parameters in the charge-transfer reactions, or at larger scales, where the placement of sacrificial anodes around a structure is the goal of the simulation. In some cases, linking the simulations at both these scales is necessary and also achievable with the Corrosion Module.

Learn more### Nonlinear Structural Materials Module

The Nonlinear Structural Materials Module augments the mechanical capabilities of the Structural Mechanics and MEMS Modules by adding nonlinear material models, including large strain plastic deformation capabilities. When the mechanical stress in a structure becomes large, certain nonlinearities in the material properties force the user to abandon linear material models. This situation also occurs in some operating conditions, such as high temperature.

The module adds elastoplastic, viscoplastic, creep, and hyperelastic material models. User-defined material models based on strain-invariants, flow rules, and creep laws can easily be created directly in the user interface with the built-in constitutive laws as a starting point.

Learn more### Mesh Selections for Creating New Boundaries and Domains

Mesh Selections are now available for subdividing an imported mesh. A mesh which was not created with COMSOL's native mesh generator but imported from another software may not have the desired domain and boundary partitioning. The new Ball, Box, Join Entities, Delete Entities, and Create Vertex operations allow for grouping existing mesh elements and make it easy to assign boundary conditions and material properties where desired.

View Screenshot1. A legacy mesh without an associated CAD geometry is imported. The mesh elements on the boundary are grouped in a way that is not suitable for the wanted analysis.

2. A boundary condition will be applied to an annular ring. Yet only half of the ring can be selected as the other half is grouped with other boundary elements.

3. The new Mesh Selection operations are used to form the other half of the annular ring. A boundary condition can now be assigned to the annular ring.

### STL File Export

You can now export the geometry, mesh, or deformed mesh to the STL
(Standard Tessellation Language) file format (file extension **.stl**).
The format represents a geometry with a triangular surface mesh and
was originally used for stereolithographic 3D printing, but is now
supported by many CAD packages for standardized file import/export
of triangulated geometry data. This and earlier COMSOL Multiphysics
versions also allow for the export of geometries on the Parasolid
.x_t and .x_b formats.

### Extrude, Revolve, and Sweep Directly in 3D

You can now extrude, revolve, or sweep planar faces directly in a 3D geometry without first defining a Work Plane. For the revolve operation, the axis of rotation can be specified directly in 3D or in a local coordinate system defined by the planar face. Sweeps can now be made along a sequence of edges of an already existing geometry, as well as along parametric curves.

View Screenshot### Efficiency when Working with Large Models

You can disable the Automatic rebuild of geometry sequences, in Preferences, which will allow you to modify Physics settings without having to wait for the geometry to rebuild. This makes working with large models faster. In this case, full geometric associativity automatically maps material settings and boundary conditions to the new geometry at the time of mesh creation.

View Screenshot### Meshing using Virtual Operations

Virtual Operations were added in Version 4.2. They allow for simplifying a CAD model without changing the underlying surface curvature or topology. By applying Virtual Operations, a much more useful mesh is produced that accurately represents the surface shape without adding too many elements. Version 4.3 adds to the suite of Virtual Operations for geometry modification with the new Ignore Faces and Form Composite Domains operations. In addition to 3D, Virtual Operations are now also available for 2D modeling.

View ScreenshotAdditional Virtual Operations are now available for local control over mesh layout and density. The new Mesh Control operations for Vertices, Edges, Faces, and Domains make it possible to add geometric features exclusively for the purpose of controlling the local mesh properties. Geometric objects used for Mesh Control do not affect the underlying subdivision of edges, faces, or domains. Virtual Operations for Mesh Control are particularly important for CFD simulations where regions of known rapid changes or steep gradients can be meshed with higher element density or different element shapes.

View Screenshot### New Nonlinear Solver

The new Double Dogleg solver addresses a larger class of highly nonlinear simulations and complements an earlier Newton solver. As always in COMSOL, if a nonlinearity is detected in a model, a nonlinear solver is automatically engaged.

The Double Dogleg solver can be described as a Trust region solver and is a sophisticated combination of the Steepest descent and Newton-Raphson methods. This new solver is the default for mechanical contact in the Structural Mechanics and MEMS Modules, and is available as an option for any other simulation type.

View Screenshot### New Multiple-Parameter Sweep User Interface

A new user interface for parametric sweeps with multiple parameters allows for easy specification of sweeps over one, two, or more parameters. Select between sweeping for all combinations of the given parameters or only a specified subset of combinations. For results and visualization, select directly from a drop-down list for each parameter or parameter combination.

View Screenshot### Control Active Physics from Model Wizard

The Model Wizard has a new Selected physics utility for controlling precisely which Physics should be active when adding a Study. This simplifies multiphysics modeling with several Physics and Studies and avoids unnecessary editing of Studies that have already been added.

View Screenshot### Cluster Sweep and Batch Sweep

New Cluster Sweep and Batch Sweep user interfaces allow for easy definition of massively parallel and independent parametric sweeps. You can start, stop, and restart jobs for individual parameter combinations as well as access parametric sweep results before the full sweep is complete. For users of a Floating Network License, the Cluster Sweep option offers optimized information transfer between a COMSOL Client and a COMSOL Server. This allows for jobs to be run on a remote cluster over limited bandwidth local-area network or internet connections. For users of a Named Single User License or CPU License, the Batch Sweep option is available for multicore shared-memory computers.

View Screenshot### Control the Physics Tree per Study Step

A new Study step tool allows you to modify the Physics tree and variables for each study step. You can disable and enable Physics settings per study step to create a customized analysis sequence. The results of one Study step can be used as input to the next one, where each Study step can run a slightly different version of the same model.

View Screenshot### Report Generator Saves to Microsoft^{®} Word Format

Reports can now be saved as .docx files for use with Microsoft® Word, in addition to the already available HTML format. The 2007 and 2010 Office versions of Word are supported. Reports can now be augmented, from within COMSOL, with text segments that include formatted text using special character formats for user interface labels, strong (bold), emphasis, code segments, equation variables, constants, subscripts, and superscripts. There is also support for Greek letters and dashes. A new Equation node supports creating custom equations by using LaTeX commands or importing an image.

View Screenshot### Visualize on Demand

You can disable the Automatic update of plots, in Preferences, which will allow you to load and manipulate large models without having to wait for visualizations to be rendered during your workflow. This makes working with large models quicker and easier. Visualization of each plot group is then triggered manually by simply clicking a plot button.

View Screenshot### New Visualization and Results Tools

Among the new visualization and results tools are 3D and 2D fast far-field plots for RF Module and Acoustics Module applications. Comet tail plots for the Particle Tracing Module allow for simultaneous visualization of position and velocity of the particles.

### Model Library

The Model Library now supports partially stored example models. This allows for many more tutorial models to be easily accessible without occupying disc space.

You can download large tutorials and new tutorials on demand from the Model Library Update.

Solution time information is now available for each model together with information on which hardware configuration was used.

View Screenshot### COMSOL Desktop Updates

The COMSOL Desktop has a new GUI layout with easy-to-reach placement of buttons in settings windows. It is easy to switch between the new and old layout.

You can now, directly from Preferences, control both the extent of solution storage in memory and the number of processors used on a multicore computer.

Physics settings as well as Definitions for variables and parameters can be sorted based on space dimensions; all settings can be grouped into folders named Domain, Boundary, Edge, and Point.

View Screenshot### Fast Meshing

Users of the CAD Import Module or one of the LiveLink products for CAD will benefit from fast meshing in version 4.3, particularly when using Virtual Geometry operations. A number of important updates to the meshing algorithms have made this possible. In addition, mesh quality has been improved.

### New and Updated File Formats

The CAD Import Module and the LiveLink products for CAD now support the following new and updated file formats:

- Creo™ Parametric 1.0 (new)
- ACIS® (SAT) R22
- CATIA® V5 R21 (needs license for File Import for CATIA V5)
- Inventor® 2012
- Parasolid® R23, R24
- SolidWorks® 2012

### LiveLink™ for Pro/ENGINEER^{®} and LiveLink™ for Creo™ Parametric

The LiveLink for Pro/ENGINEER now automatically links parameter names from Pro/ENGINEER to COMSOL for easier set up of parametric sweeps. The LiveLink for Creo Parametric also comes with this functionality.

View Screenshot### LiveLink™ for SolidWorks^{®}

The LiveLink for SolidWorks now automatically links parameter names from SolidWorks to COMSOL for easier set up of parametric sweeps.

For faster synchronizing of large CAD models, you can now control associativity per geometric entity type.

The One Window Interface for SolidWorks now comes with support for particle tracing, when combined with the Particle Tracing Module.

Additional updates to the One Window Interface include: selections and selection highlighting improvements, Virtual Geometry operations, display of progress information for the solution process in a docked window, connection to external server or cluster.

View Screenshot### LiveLink™ for Inventor^{®}

The LiveLink for Inventor now automatically links parameter names from Inventor to COMSOL for easier set up of parametric sweeps.

View Screenshot### LiveLink™ for MATLAB^{®}

You can now update the MATLAB installation folder directly in Preferences. A new method has been introduced for disabling automatic variable updates; this can give better performance when working with large models. The LiveLink for MATLAB has the following new functions:

**mphimage2geom**Convert image data to geometries.**mphevalpoint**Evaluate expressions at geometric vertices.**mphmean, mphmin, mphmax**Evaluate mean, minimum, and maximum of expressions in a data series.**mphevalglobalmatrix**Evaluate a global matrix, such as an S-parameter matrix.**mphsearch**User interface to search for expression, variables and tags in a model.

New functionality in existing LiveLink for MATLAB functions:

**mphnavigator**Additional nodes and information are available. You can also get solution information such as how the solution object and the solution data sets are connected.**mpheval, mphint**Selection tags are now available.**mphinterp**Extrapolation allows for evaluation of data outside the geometry.**mphplot**Contour labels for 2D and 3D models.

### Automatic Coil Excitation in 3D

Automatic coil excitation is now available for 3D coils of arbitrary shape including toroid, helicoid, and saddle. Available options are Single-Turn Coil and Multi-Turn Coil. Prior versions had this functionality for 2D and 2D axisymmetric coil models.

View Screenshot### S-parameter Computation for Terminals and Z/Y/S Conversion

Terminals now support a terminating impedance condition, in addition to the existing Current, Voltage, and Circuit conditions. Terminals will automatically define an S-parameter matrix variable that can be evaluated using a new Global Matrix Evaluation tool or exported with the Touchstone Export.

Lumped parameter matrices can now automatically be converted, for example, from admittance, Y, to impedance, Z. By specifying a characteristic impedance, it is also possible to compute the S-parameter matrix directly from Z and Y, or vice versa. For a terminal sweep and a frequency sweep in the same study, plots of lumped parameters or S-parameters as functions of frequency are created automatically.

View Screenshot### Porous Media Mixture Model

The mixture model for Porous Media and Archie's Law, previously available only for the Electric Currents interface, is now available for all the user interfaces of the AC/DC Module. For Porous Media, a dedicated subnode can be used to compute an averaged value of the electrical conductivity, relative permittivity, and relative permeability of mixtures with up to five materials. In addition, a dedicated subnode is available to compute the electrical conductivity in saturated nonconductive porous media using Archie's Law.

View Screenshot### Electric Motors and Generators in 3D

Brushless motors and generators, radial and axial flux machinery, as well as brushed DC electric motors can now be modeled in 3D thanks to a new Rotating Machinery user interface. A dedicated mixed electromagnetic potential formulation has enabled this type of analysis.

Powerful and general postprocessing tools allow quick access to any results of interest for electromachinery design including axial torque, coil currents, and field plots.

View Screenshot### Fast Far-Field Plots

New fast far-field plots make it easy to visualize the asymptotic radiation pattern for RF and microwave antennas. Far-field plots are available for 3D, 2D, and user-defined 3D cut planes. A new directivity calculation tool gives the power density that the antenna radiates in the direction of its strongest emission.

The radiation pattern from a microstrip patch antenna is visualized with the new fast far-field plots for 3D, 2D, and 3D cut planes.

### Mixture and Porous Media Material Models

Mixture and porous media material models are available for both the frequency-domain and the transient RF Module user interfaces. The conductivity can be specified using Archie's law. Volume fractions can be defined for up to 5 different materials of a mixture with different permittivity, permeability, and conductivity.

View Screenshot### Dispersive Media Material Models

Real-world materials are often dispersive: waves of different wavelength propagate at different phase velocities. The RF Module has been used to model dispersive media for quite some time where users have entered their custom equation expressions for various dispersion models.

Version 4.3 offers three important dispersive media material models as preset options for frequency-domain analysis: Drude-Lorentz, Debye, and Sellmeier.

The Drude-Lorentz model is suitable for approximating the permittivity of metals. The Debye dispersion model describes the dielectric response of an ensemble of ideal, non-interacting dipoles. Finally, the Sellmeier formula is widely used in optics for specification of the refractive index of optical materials as a function of wavelength. The different material models are also available when specifying impedance and transition boundary conditions.

View Screenshot### Easy Conversion between S, Z, and Y

A characteristic impedance input for Results now allows for conversion between S-parameters, impedance Z, and admittance Y, for already solved models. This feature is available through the Global Matrix Evaluation tool for Derived Values.

View Screenshot### Transmission Line Equation

A new Transmission Line user interface solves the time-harmonic transmission line equation for the electric potential. The interface is used when solving for electromagnetic wave propagation along one-dimensional transmission lines and is available in 1D, 2D, and 3D.

View Screenshot### More than 20 New Tutorial Models

More than 20 new tutorial models are available in the RF Module's Model Library. All of these come with step-by-step instructions and, when applicable, analytical solutions are used for validation. Among the new tutorials now available are: microstrip patch antenna, double-layered dielectric lens radome, branch line coupler, evanescent-mode cavity filter, and dielectric resonator antenna.

View Screenshot### New Solver for Mechanical Contact

The new and general nonlinear Double Dogleg solver is the new default for mechanical contact. This solver is also useful for highly nonlinear simulations such as for large strain plastic deformation or hyperelastic materials, when combined with the new Nonlinear Structural Materials Module.

### New Boundary Condition for Dynamic Cyclic Symmetry and Floquet Periodicity

A new and redesigned periodic boundary condition for solid mechanics and piezoelectric applications allows for dynamic cyclic symmetry and Floquet periodicity. In addition, an option to prescribe the periodic conditions on the entire displacement vector has been added and is the new default option.

View Screenshot### Silent Boundaries

A new low-reflecting boundary condition, also known as a silent boundary, lets elastic waves pass out from a model without reflection. This complements using Perfectly Matched Layers (PMLs) in the frequency-domain, by also providing infinite-domain absorption for time-dependent analysis. As a default, the new boundary condition applies material data from a domain to create an impedance match for both pressure waves and shear waves.

View Screenshot### New User Interfaces for Load Cases

A new mechanism for load cases allows for tagging loads or constraints with new Load or Constraint groups. Each load or constraint can be assigned to belong to a certain Load or Constraint Group. The activation of load cases is controlled through settings for each Study.

View Screenshot### Membranes

A new Membrane user interface enables modeling of prestressed membranes, claddings on solids, and inflatable flexible bags (balloons). Membranes can be seen as a representation of plane stress in a 3D geometry or as a shell without bending stiffness. Another important application area, when combining the Membrane user interface of the Structural Mechanics Module with the Acoustics Module, is for Microphone diaphragms in condenser microphones.

View Screenshot### Rigid Connectors, Kinetic Energy, Trusses, and More

The Structural Mechanics Module has a number of additional new features and improvements. For rigid connectors, there are two important additions: rigid connectors between shell edges are now available and rigid connectors from shell and solid interfaces can be attached to each other.

For the truss user interface, linear buckling is now available as well as prestressed analysis in the frequency domain.

The rate of strain and spin tensors are now available as predefined variables in the solid interfaces, strain energy density is now available for Truss, Beam, Shell, and Plate. Shell curvature data is now available as variables, which you can use to modify material, thickness, or initial stress for deep drawn sheets. Kinetic and elastic potential energy are now available for all structural mechanics user interfaces.

Gauss point results are now available for almost all stress results in Structural Mechanics, and all Gauss point results have been moved to separate groups in the plot list.

### More Material Models

The Geomechanics Module now allows for large strain plastic deformation which is important for geomechanics applications where strain levels are beyond 10%.

Tension cut-off is available for the soil plasticity and concrete materials models: Drucker-Prager, Mohr-Coloumb, Matsuoka-Nakai, Lade-Duncan, Bresler-Pister, Ottosen, and Willam-Warnke.

A number of built-in creep material models are available: Deviatoric, Potential, User-defined, and Volumetric.

### Pipe Acoustics

Combine the Acoustics Module and the Pipe Flow Module for transient acoustics in 1D pipes. Pipes can be connected to volumetric pressure acoustics domains for efficient mixed-dimensional acoustics simulations.

### Membrane-Acoustics Simulations

The new Membrane user interface of the Structural Mechanics Module allows for sophisticated microphone simulations. A combination of the Acoustics, Structural Mechanics and AC/DC Modules allows for condenser microphone modeling that includes all the relevant physics and determines the sensitivity for the specific microphone geometry and material parameters. This involves solving a fully coupled finite-element model for the acoustic-electric-mechanical system, using a linear perturbation solver in the frequency domain. The Thermoacoustic, Electrostatic, and Membrane user interfaces are used in such simulations.

View Screenshot### Silent Boundaries

A new low-reflecting boundary condition, also known as a silent boundary, lets elastic waves pass out from a model without reflection. This complements using Perfectly Matched Layers (PMLs) in the frequency-domain, by also providing infinite-domain absorption for time-dependent analysis. As a default, the new boundary condition applies material data from a domain to create an impedance match for both pressure waves and shear waves.

View Screenshot### Fast Far-Field Computations, Thermoacoustic-Shells, and Cyclic Symmetry

A new calculation method enables very fast and high resolution far-field plots in 1D, 2D, and 3D.

The Thermoacoustics modeling tools have been updated with a new Thermoacoustic-Shell Interaction user interface: combine the Acoustics Module with the Structural Mechanics Module for bidirectionally coupled thermoacoustic-shell simulations. In addition, Thermoacoustic modal analysis is now available.

A new and redesigned periodic boundary condition is available for cyclic symmetry and Floquet periodicity. Applications span pressure acoustics, thermoacoustics, solid mechanics, as well as elastic, and poroelastic waves.

View Screenshot### Piezoresistivity

The MEMS Module has three new user interfaces for Piezoresistivity simulations corresponding to the analysis cases: Piezoresistive shells, domains, or with boundary currents. These new user interfaces are accompanied by a Piezoresistive material library for single crystal and polycrystaline p- and n-doped silicon.

### New Linear Elastic Dielectric Material Model, Coordinate Visualizations, and More

The Electromechanics interface has been improved and upgraded in a number of ways including new designs of the Linear Elastic Dielectric and Linear Elastic material models. The new Linear Elastic Material can be used for more efficient simulations when solving for the electric potential within a solid is not required. This makes it easier to control which domains have active electric and elastic physics settings.

New coordinate visualizations make it easier to visualize the different material orientations in stacks of piezoelectric materials.

A new and redesigned periodic boundary condition for solid mechanics and piezoelectric applications allows for dynamic cyclic symmetry and Floquet periodicity. In addition, an option to prescribe the periodic conditions on the entire displacement vector has been added and is the new default option.

View Screenshot### S-Parameter Calculations for Piezoelectrics and Electromechanics

The Terminal boundary condition now supports a terminating impedance condition, in addition to the existing Current, Voltage, and Circuit conditions. This feature is available for the Electrical, Piezoelectric Devices, and Electromechanics user interfaces. Terminals will automatically define an S-parameter matrix variable that can be evaluated using a new Global Matrix Evaluation tool or exported with the Touchstone Export. Lumped parameter matrices can now automatically be converted, for example, from admittance, Y, to impedance, Z. By specifying a characteristic impedance, it is also possible to compute the S-parameter matrix directly from Z and Y, or vice versa. For a terminal sweep and a frequency sweep in the same study, plots of lumped parameters or S-parameters as functions of frequency are created automatically.

View Screenshot### Biased Resonator Simulation Verification

An important application for the Electromechanics multiphysics interface is simulation of biased MEMS devices. A tutorial for electrostatically actuated MEMS resonators has been updated with information on experimental verification. The modeled device is driven by an AC + DC bias voltage applied across a parallel plate capacitor. The normal mode shapes and frequencies are computed, as a function of applied bias. These are compared with published experimental data obtained from a fabricated device: F.D. Bannon III, J.R. Clark, and C. T.-C. Nguyen, "High-Q HF Microelectromechanical Filters", IEEE Journal of Solid State Circuits, vol. 35, no. 4, pp. 512–526, 2000. The example model will be available from the Model Library Update.

### Turbulent Drift, Vacuum Pump, and More

Turbulent drift for the Mixture Model user interface has been updated for better accuracy and stability.

The Vacuum Pump boundary condition is now a separate boundary condition with enhanced graphical support which shows the intended flow direction while setting up a model.

The numerical stabilization schemes have been updated to increase accuracy for meshes with high aspect ratio.

New numerical scaling has been introduced for time-dependent turbulence. The new scaling method makes for more robust simulations.

### Turbulent Mixing

The user interfaces for Transport of Diluted Species and Transport of Concentrated Species have a new Turbulent Mixing feature. Turbulent Mixing models the additional mixing caused by turbulence by adding turbulent diffusivity to the molecular diffusivity.

View Screenshot### Time-Dependent Angular Velocity

Time-dependent angular velocity has been added in the Rotating Domain user interface. In the new implementation, the displacement angle of the rotating domain is defined as an ODE variable and integrated using the rotational frequency input. The implementation supports all types of definitions of time-dependent frequencies including analytic and interpolation functions.

View Screenshot### Solar Irradiation and other Heat Radiation News

A new option, solar position, is available to define external radiation source in 3D for all interfaces including surface-to-surface radiation features. This option provides a convenient way to define the direction and intensity of the incident radiation coming from the Sun from the position on the Earth, the date, and the time.

Refractive index is now available as a parameter for radiation in participating media. This parameter makes it possible to define a refractive index that is different than 1.0, enabling modeling radiation through, water, glass, and other media.

Surface-to-surface radiation can now be used together with the Thin Conductive Shell user interface, enabling radiative heat transfer between thin structures.

View Screenshot### Interior Thin-Walls for Turbulent Flow with Heat Transfer

A new boundary condition, Interior Wall, is available on interior boundaries in the Conjugate Heat Transfer and Non-Isothermal Flow interfaces. It makes it possible to define a wall condition between two fluid domains. This is especially useful for representing thin walls as interior boundaries. You no longer need to define a solid domain with a wall boundary condition on both sides, which can result in a dense mesh. This boundary condition implements wall functions when using the k-epsilon or k-omega turbulence (requires the CFD Module) model.

View Screenshot### Total Heat, Updated Inflow, Enthalpy, and Humid Air

New choices are available to define the total heat source or the total heat flux in Line Heat Source, Layer Heat Source, and Edge Heat Flux features. These options simplify the definition of models where the total heat source or heat flux is known because you no longer have to convert it into heat flux (or heat source) per surface area or length.

The inflow heat flux boundary condition has been improved so that heat transport into the domain is controlled by the flow convection. This change prevents unphysical results like computing high temperatures in no-flow parts of inflow heat flux boundaries.

Enthalpy and internal energy are now calculated using state integrals. This gives increased accuracy for heat and energy balances.

A new material, humid air, is available in the Liquids and Gases material library.

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### Inductively Coupled Plasmas

A new solver for Inductively Coupled Plasmas (ICP) provides increased robustness and allows more complicated systems and plasma chemistries to be modeled. In version 4.3, it is recommended to drive ICP coils with a fixed power. An important new tutorial model of Plasma Enhanced Chemical Vapor Deposition (PECVD) illustrates using the new solver.

### Ion Angular Energy Distribution Function

When combined, the Plasma Module and the Particle Tracing Module allows for computing and visualizing the ion angular energy distribution function (IAEDF) using a new 2D histogram plot.

View Screenshot### Reduced Field in the Two-term Boltzmann Equation

For the Two-term Boltzmann Equation user interface, it is now possible to solve for a reduced electric field using the new "Reduced Electric Fields" study type.

View Screenshot### Electronegative Inductively Coupled Plasma Tutorial

Electronegative plasmas exhibit different characteristics than electropositive discharges due to the presence of negative ions. This model simulates an inductively coupled plasma for a mixture of argon (30%) and oxygen (70%). The plasma chemistry consists of 62 reactions and 15 species. The negative ions are held in the core of the plasma because they cannot escape the ambipolar field.

View Screenshot### Controlled Diffusion Micromixer

A new version of the controlled diffusion micromixer example comes with flow-rate based inlet boundary conditions and shows how the concentration dependent viscosity affects the velocity profile.

### Transitional Flow

The transitional flow user interface, which solves the Lattice-Boltzman equation, is now also available in 3D. You can choose velocity space resolution by selecting from a list of predefined quadrature settings. In addition, optimized solver suggestions allow for controlling trade-off between memory usage and solution time.

View Screenshot### Sorbing Solute and Pesticide Transport

The Subsurface Flow Module features two important tutorials with highly detailed step-by-step instructions: Sorbing Solute and Pesticide Transport and Reaction in Soil.

In the Sorbing Solute example, water ponded in a ring on the ground moves into a relatively dry soil column and carries a chemical with it. As it moves through the variably saturated soil column, the chemical attaches to solid particles, slowing the solute transport relative to the water. In addition, the chemical concentrations decay from biodegradation in both the liquid and the solid phase.

In the example of Pesticide Transport and Reaction in Soil, the degradation of the insecticide Aldicarb is simulated. The carbamate initially decomposes into a sulfone which subsequently decays into a sulfoxide. Biodegradation reactions provide important pathways to reduce the amounts of toxic substances. A second modeling stage uses the computed reaction kinetics in a space-dependent model that describes the contamination of soil through Aldicarb transport and reaction.

View Screenshot### Brownian Force

A new Brownian Force has been added to the Particle Tracing Module for fluid flow applications. This type of force is used to model diffusion of particles suspended in a fluid and can be used to perform Monte Carlo simulations.

View Screenshot### Schiller-Naumann, Magnetophoretic and Thermophoretic Force

New option for drag force, Schiller-Naumann, is used when the relative Reynolds number between the background fluid and the particles is greater than one.

The Magnetophoretic Force option is used to model the transport of neutral particles in a magnetic field where the field gradients influence the particles.

The Thermophoretic Force option is used for transport of particles from regions of high to low fluid temperature.

View Screenshot### Sticking Probabilities

Sticking probabilities and expressions are now available as boundary conditions. Particles making contact with the wall can stick, freeze or disappear on the wall according to an arbitrary expression, or a probability. This type of boundary condition is important for both Charged Particle Tracing and Particle Tracing for Fluid Flow.

View Screenshot### Filtering of Particle Trajectories

Particle Trajectories can now be filtered. Choosing a fraction or a specific number of particles to render, allows for faster visualization when solving for a large number of particles.

### Particle-Particle Interactions

The Particle Tracing Module has the following particle-particle interaction forces available: Coulomb, Lennard-Jones, and user-defined. A requirement for particle-particle interaction is that forces must be continuously acting for all distances between particles.

View Screenshot### Secondary Particle Emission

Secondary particle emission is now available as an option for the Wall Condition. The number of secondary particles to be released can be a mathematical expression, such as a logical expression containing the particle energy.

The initial velocity of a secondary particle can be given by a number of options: isotropic or hemispherical where a secondary particle is emitted in a random direction, specular reflection, or user defined.

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### Particle Evaluation and Distribution Functions

A new Particle Evaluation feature for Derived Values writes numerical particle data to the Results window. This allows for inspection of individual particle characteristics such as the particle velocity.

Distribution functions are now available for: initial mass of the particles in the Particle Tracing for Fluid Flow user interface and auxiliary dependent variables in all user interfaces.

### Shell Electrodes

The Batteries & Fuel Cells Module comes with a new Electrode, Shell user interface for modeling of thin electrodes.

View Screenshot### Capacity Fade of a Li-ion Battery

This example demonstrates the new Events interface for simulating 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 in the negative electrode due to a parasitic lithium/solvent reduction reaction.

### Separator Domain

A new separator domain property is available for the Lithium-Ion Battery and Battery with Binary Electrolyte user interfaces. Properties of the separator include: electrolyte volume fraction, electrolyte conductivity, salt diffusivity, transport number, active dependence, and effective transport parameter correction.

View Screenshot### Potentiostatic Control

New Electrode Potential, Reference Electrode, and Electric Reference Potential features for handling potentiostatic control of electrochemical cells in all Electrochemistry interfaces.

View Screenshot### All-Solid-State Lithium-Ion Battery

A new tutorial model shows how to use the Tertiary Current Distribution interface to model the currents and electrolyte mass transport in a thin-film all-solid-state lithium-ion battery. A separate Transport of Diluted Species interface is coupled to the electrochemical reactions to model the mass transport of lithium in the positive electrode. Various discharge currents are studied, and the different sources of voltage losses are analyzed.

View Screenshot### Increased Performance and New Models

Performance is greatly increased for simulations with many chemical species. This is thanks to a new uniform scaling of concentration variables.

New models include: Protein adsorption, Dissociation in a tubular reactor, and Compression ignition chemistry in an engine, with more than 300 reactions.

View Screenshot### Reaction Engineering for Porous Media and Improved CHEMKIN Import

Reaction engineering chemistry can now be exported to the following interfaces for transport in porous media: Free and Porous Media Flow, Darcy's Law, Heat Transfer in Porous Media, Species Transport in Porous Media, and Solute Transport.

The new version of the Chemical Reaction Engineering Module also features greatly improved CHEMKIN import with support for hundreds of reactions.

View Screenshot### Moving Boundary Smoothing and Boundary Stretch Compensation

The Electrodeposition Module now features moving boundary smoothing of Depositing Electrode Surface ensures robust material build-up of thick deposited layers. A new boundary stretch compensation method is available for mass conservation on moving boundaries.

View Screenshot### New Electrodeposition Tutorials

A new tutorial shows modeling the deposition of an inductor coil in the μm-scale, where diffusion limitations govern the deposition rate. A 10 μm thick photoresist mask has been used create the deposition pattern. As the deposition process continues the depth of the pattern created by the mask decreases, which in turn affects the current distribution over the active surface.

An example of Electrodeposition on a Resistive Patterned Wafer models time-dependent copper deposition on a resistive wafer in a cupplater reactor. As the deposited layer builds up, the resistive losses of the deposited layer decrease. The benefit of using a current thief for a more uniform deposit thickness is demonstrated.

In the new Superfilling Electrodeposition tutorial, the deposition rate is accelerated in concave areas of the surface, where the concentration of a surface catalyst is increased due to the area contraction of the moving boundary. The simulation shows that concentration of a surface catalyst is increased due to the area contraction of a moving boundary.

### Shell Electrodes

The Batteries & Fuel Cells Module comes with a new Electrode, Shell user interface with Electrode and Depositing Electrode options for modeling of thin electrodes.

View Screenshot### Potentiostatic Control

New Electrode Potential, Reference Electrode, and Electric Reference Potential features for handling potentiostatic control of electrochemical cells in all Electrochemistry interfaces.

View Screenshot### Time-Dependent Sensitivity and Optimization

Time-dependent sensitivity and optimization is now generally available in the Optimization Module. A new tutorial example for time-dependent optimization starts from the nonlinear model equation:

and shows how to find the long-term periodic steady-state solution to a nonlinear time-dependent simulation. The model equation is representative of certain plasma simulations but is also important in other physics disciplines. Solving such problems with the time-dependent optimizer can accelerate computations significantly.