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1034: Particle tracing feature gives unexpected results The particle tracing feature in COMSOL Multiphysics sometimes gives unexpected results in Axial symmetry (2D) application modes. Workaround for...
1033: Installation of SolidWorks Live Connection add-in fails On 64 bit Windows Vista the SolidWorks Live Connection add-in to SolidWorks is not installed when installing COMSOL Multiphysics, and the steps...
1032: License manager fails to start as a service on Vista or Windows... The version of the license manager that is shipped with COMSOL Multiphysics 3.4 cannot be installed as an automatic service in Windows Vista and...
1031: Flux through interior boundaries When plotting the normal flux through the boundaries in my model, I am surprised to see that two adjacent boundary segments have opposed flux. This...
1030: Error message: "Out of memory" The error message "Out of memory" occurs mostly on 32-bit platforms, due to the inherent limit in memory address space. We recommend a 64-bit...
1029: My transient 3.3 model does not work in version 3.4 I have a transient model that worked fine in COMSOL 3.3a but when I open it in version 3.4 and run it I get the error message Error: Time 0: ...
1028: Electric and Magnetic Dipoles How can I model an oscillating/radiating electric/magnetic dipole in Comsol Multiphysics? There are two ways to model an electric dipole and two...
1025: Level Set method for two-phase flow, how does it compare with the... I am new to COMSOL Multiphysics and have seen that you can use the Level Set method to track phase boundaries, for example in a rising bubble. I...
1024: 3.4 installation DVD hangs or reboots my Windows system When I insert the COMSOL 3.4 installation DVD, my Windows system reboots or hangs showing a blue screen. We have received this problem report from a...
1023: Support for RedHat Enterprise 5 I cannot find RedHat Enterprise 5 on your System Requirements page. Is it safe to run COMSOL on that platform? RedHat Enterprise 5 is not yet part...
1022: Updating the COMSOL License Manager (Error: License server system... I just received the new license file for COMSOL 3.4. The first line in the license file starts with the word SERVER, which means a COMSOL License...
1021: Thermal turbulent wall functions give incorrect heat flux In COMSOL Multiphysics 3.4 there is a problem with the thermal wall function boundary condition, which is available in the turbulent fluid-thermal...
1020: MATLAB 2007b window does not appear when started with COMSOL... When I start COMSOL 3.4 with MATLAB 2007b, neither MATLAB nor the COMSOL Multiphysics user interface appear. This problem has been reported by some...
1019: Can I solve systems of nonlinear algebraic equations with COMSOL? Can I solve nonlinear equation systems with COMSOL? Yes, you can. The easiest way is to use the daspk solver from the COMSOL Script command line....
1018: Error message: UnsatisfiedLinkError: libfldynload.so:... I use Debian Linux 3.1, 32-bit. When I start COMSOL 3.4 with MATLAB 2007a or MATLAB 2007b, the following error...
1017: Error: Fatal exception occurred. Program will exit. During installation of COMSOL Multiphysics 3.4 on Windows the, error message "Fatal exception occurred. Program will exit." or "Unsatisfied link...
1016: License borrowing in COMSOL 3.4 How to borrow license keys on a floating network license License borrowing means that you can use COMSOL (for a limited time) without a network...
1015: Error: Error in callback, Error in built-in function javaMethod If you have a multicore machine, and start COMSOL Script in 32-bit mode with the Desktop environment enabled (for example on Windows, with the...
1014: Error message: java: xcb_xlib.c:52: xcb_xlib_unlock: Assertion... I have SuSE Linux 10.3 or Fedora Core 8. When I start COMSOL, the following error occurs: java: xcb_xlib.c:52: xcb_xlib_unlock: Assertion...
1011: Creating Flash® Animations from COMSOL results plots Suppose you want to create an animation of your model to put on a web page or maybe to include in a presentation. Using the built-in avi or...
1010: Error 7067, System matrix is zero I get the error message "Error 7067, System matrix is zero". What can it be? The problem could be that you only made surface...
1009: How do I model materials with gain/losses? I am using a time-harmonic application mode to solve an electromagnetics problem. If I want to introduce lossy materials, or materials with gain,...
1008: SolidWorks import: Error 1095, failed to load model... I imported a SolidWorks geometry and saved to an mph file. Next time I start COMSOL Multiphysics and try to open the mph file I get the error...
1007: Solving Algebraic and Transcendental Equations How can I solve algebraic equations and transcendental equations in COMSOL? The Global Equation interface can handle more than ODEs. By skipping the...
1006: Calling external programs from COMSOL Script I have an external program I need to call from COMSOL Script, is this possible? It is easy to call executable programs from COMSOL Script with the...
1005: Linking COMSOL to external functions Can COMSOL Multiphysics be connected to external functions written in other languages? Yes, it is possible to link COMSOL Multiphysics to external...
1004: Resolving the Skin Depth Why do the currents in my metal look strange? How can I get a realistic solution at high frequencies? Not resolving the skin depth is one of the...
1003: Plotting the mesh together with the solution How can I see both the mesh and the solution of my COMSOL Multiphysics model? The most straight-forward way to see the mesh of a COMSOL Multiphysics...
1001: Running COMSOL in parallel mode This solution describes how you enable parallel use of the processors on a multicore or multiprocessor computer. Introduction COMSOL supports...
999: Error: ld.so.1, LMCOMSOL Why do I get a message about missing symbols when starting the COMSOL 3.3 License Manager on Sun? When lmgrd is started , the following error...
990: Error: 3016, Internal error CAD import. In COMSOL Multiphysics version 3.3 the following error message can occur on Linux and Sun platforms: Error: 3016 Internal error CAD import. This...
989: Does COMSOL support the Mac Intel platform? Yes, see further on the system requirements page.
987: MATLAB compatibility Which versions of MATLAB can I interface COMSOL Multiphysics to? COMSOL 3.4 For full MATLAB version information see the system requirements...
986: Error messages, general What is the meaning of the error message that Comsol Multiphysics gives me? The Comsol Multiphysics documentation contains a section that summarizes...
985: Warning message: Inverted mesh element near coordinates (x,y,z) Why do I get a warning about an inverted mesh element? Either of the following two solutions should fix the problem: If you are experiencing...
984: How to do a parametric study for a time dependent or an eigenvalue... I want to solve a time dependent or an eigenvalue problem for many different values of a parameter. Can this be done automatically? The parametric...
983: Error message: Internal Error in Geometry Decomposition Why do I get the error message “Internal Error in Geometry Decomposition”? This error usually means that Comsol Multiphysics failed to...
982: Axisymmetric plot swept to 3D How do I make a 3D plot from an axisymmetric 2D calculation? COMSOL Multiphysics 3.4This is described in the COMSOL Multiphysics User's Guide...
980: Can I run COMSOL Multiphysics in batch mode? I would like to run my COMSOL Multiphysics computations in batch mode. If I have neither COMSOL Script nor MATLAB. If you have COMSOL Script, you...
979: COMSOL Script or MATLAB? What is the difference? Is there any difference between interfacing COMSOL Multiphysics to MATLAB on one hand and using COMSOL Script on the other hand. COMSOL Script...
977: How do I turn an interior boundary into a perfect conductor in my... I am using the In-Plane TM Waves application mode in the RF Module. I would like to embed a perfect electric conductor, but this boundary condition...
975: Create a graphical user interface for customized applications I would like to generate my own graphical user interface for an application generated in COMSOL Script, or for a COMSOL Multiphysics model. Using...
974: Error message: License Error - FLEXnet error -9 (Invalid host. The... I have a PC/Windows or a Macintosh computer with an NSL/CPU license for COMSOL Multiphysics. My COMSOL license file is locked to a network...
973: My flux calculation seems wrong I am solving a diffusion-like problem in COMSOL Multiphysics and discovered that boundaries that are defined with insulation/symmetry conditions...
971: Error message: FLEXnet error -84 (USER_BASED license has no... I have a Named Single User License (NSL) for COMSOL Multiphysics and get an error message. When I click the "Details>>" button in the error...
970: Improving convergence for ALE and parameterized geometry When you are working with the Moving Mesh (ALE) and Parameterized Geometry application modes to move things around, the computational mesh gets...
968: Error message: FLEXnet Licensing error: -103 I am getting an error message and when I click "Details>>" I can read the following log: Exception: ...
966: Background and Theory References on Equation-Based Finite Element... Where can I find documentation on the theoretical background of the algorithms and techniques used by COMSOL Multiphysics for Finite Element...
965: 3D Euler Beam coordinate system 3D beams that are modeled on edges of a 3D structure need a local coordinate system for a number of reasons. Indata: You need a coordinate system...
964: Error message: Failed to find a solution: No convergence... I get this message: Failed to find a solution: Maximum number of Newton iterations reachedReturned solution has not converged. This message is...
962: Which element types are supported in COMSOL Multiphysics? How elements are defined and used in COMSOL MultiphysicsThe use of elements in defining a finite element model in COMSOL Multiphysics differs...
960: Error message: License error -15 Cannot connect to license server... I get this error message: License error -15 Cannot connect to license server system The text in the "Details" window shows something...
955: Optimization Can I do optimization in a COMSOL Multiphysics model? Optmization Lab If you run COMSOL Multiphysics in combination with the Optimization Lab, it is...
953: Error message: Singular Matrix What does the error message "Singular Matrix" mean? The problem is that the stiffness matrix of the linear system is singular and the...
952: Negative concentrations Why do I get negative values of the concentration? There are several possible reasons for negative concentrations: Numerical errors The most common...
951: How do I calculate the capacitance matrix of a multiconductor system? I have set up a model of a number of conductors. How can I compute all the entries of the multiconductor capacitance matrix? The COMSOL...
947: License manager error: TCP port number... I cannot run COMSOL Multiphysics on my system, and I get a license error message. When I look in the license manager log file I see this: 9:55:20...
945: Imposing both Neumann and Dirichlet condition on a single boundary I would like to solve the equation div(grad u) = 0 in 1D with the following boundary conditions: x = 0: u = 2 AND du/dx = 3 x = 1: no conditions...
942: How do I use coupling variables from the command line? How do I use coupling variables from the command line, for example to make periodic boundary conditions or impose an integral constraint in a script...
940: How to create a helix geometry object in COMSOL How do I create a helix in COMSOL Multiphysics? The are three available commands, helix1, helix2, and helix3, that can illustrate how low-level...
939: Can COMSOL Multiphysics handle polar, spherical, and cylindrical... Can COMSOL Multiphysics handle polar, spherical, and cylindrical coordinates? And how can I define these coordinates? You can define your own...
935: Interpolation of measured data I have data tables for my dependent material properties. For instance, I have values of the thermal conductivity at some different temperatures, and...
933: Troubleshooting graphics adapter problems Troubleshooting graphics adapter problems Background COMSOL Multiphysics relies on hardware accelerated graphics rendering for mesh visualization...
923: Installation of COMSOL Multiphysics with hardware lock (dongle) COMSOL dongle licenses are supported on the Windows platform. Please follow the steps below: Install the COMSOL products on your PC using the...
922: Why do I get an error when calling COMSOL Script functions from... When calling a COMSOL Script or MATLAB function from COMSOL Multiphysics, I get an error message such as Matrix power is only defined for square...
921: Time-step control How does COMSOL Multiphysics determine the time-step size? In all of the COMSOL Multiphysics solvers for time-dependent problems, the time step is...
916: Electromagnetic coils: multi-turn with fixed total current and skin... How can I model a multi-turn current-carrying circular or cylindrical coil with skin effect? How do I specify a fixed total current in each winding...
913: Computing Time and Space Integrals How do I compute time integrals in my time-dependent COMSOL Multiphysics model? How can I calculate a space integral? The best way to compute time...
909: Can COMSOL Multiphysics be used for TEM mode analysis? Can COMSOL Multiphysics be used for TEM mode analysis? Yes, you can make a TEM, or rather quasi-TEM mode analysis of microstrip line cross sections...
906: How do I extract the stiffness matrix of my problem? How do I extract the stiffness matrix of my problem? The assemble command can be used to extract the stiffness matrix and other system matrices from...
905: Smoothed step transitions in COMSOL Multiphysics When you provide a function, coefficient or material property as a step function to COMSOL Multiphysics, you may experience convergence problems....
903: License error -96, License error -15 When the COMSOL license manager is running on a computer with an active firewall, and the COMSOL Multiphysics client is outside of that firewall,...
902: Thin film approximation, contact resistance In modeling of transport by diffusion or conduction in thin layers, we often encounter large differences in dimensions of the different subdomains...
895: Can COMSOL Multiphysics handle left-handed materials? Can COMSOL Multiphysics handle left-handed materials? Introduction Left-handed materials/media is an important topic in optics and ...
881: Electromagnetic coils: Multi-turn without skin effect How can I model a multi-turn current-carrying coil in the DC and low frequency AC regime when the skin depth is much larger than the cross-section...
878: Should I use the RMS, the peak, or the instantaneous value to... Should I use the RMS, the peak, or the instantaneous value to specify sources for electromagnetic fields? How can I specify the phase angle? The...
877: What are the relative and absolute tolerance for a time dependent... What are the relative and absolute tolerances (Rtol and Atol) for a time dependent problem? How do I know which values to give them? In the manual...
875: What is meant by degrees of freedom (DOFs) in COMSOL Multiphysics? What is meant by degrees of freedom (DOFs) in COMSOL Multiphysics? The solution time and memory requirements are strongly related to the number of...
866: What hardware platform do you recommend for COMSOL Multiphysics? I am going to buy a new computer for COMSOL Multiphysics. What hardware platform do you recommend? What about CPU speed and amount of RAM?...
865: The inlet velocity is set as 4*Umax*s*(1-s). What does that mean? The inlet velocity profile in the model library model "Flow Past a Cylinder" is set to 4*Umax*s*(1-s). What does that mean ? The curve...
852: How can I model nonlinear magnetic materials? How can I model nonlinear magnetic materials? How can I introduce an experimental B-H curve? A nonlinear magnetic material can be implemented either...
850: Is there an 'open-boundary condition' for electrostatic or... I want to simulate an electrostatic or a magnetostatic problem in free space. How should I set up my simulation domain, and what boundary condition...
838: Can COMSOL Multiphysics import images? Can COMSOL Multiphysics import images? Yes, images of the formats BMP, JPEG, PNG, and TIFF can be converted into 2-D or 3-D geometry objects,...
830: Handling memory intensive models Handling memory intensive models Introduction On 32-bit platforms there is a theoretical upper limit of addressable memory (physical RAM + disk swap...
829: I want to extract my COMSOL Multiphysics data for external... I want to extract my COMSOL Multiphysics data for external postprocessing. BasicThe simplest way to extract data from a plot in COMSOL Multiphysics...
828: Obtaining a Hostid for FLEXnet licensing How do I obtain the FLEXnet (formerly FLEXlm) Hostid? For many license types in the COMSOL product family, your COMSOL sales representative will ask...
816: How do I solve a PDE with space derivatives of order higher than two? How do I solve a PDE with space derivatives of order higher than two? For example, the equation uxxxx + uxxyy + uyyyy = f for a function u(x,y). ...
808: Can I compute the magnetic forces in COMSOL Multiphysics? Can I compute the magnetic forces in COMSOL Multiphysics? Yes, there are three different methods that can be used under different circumstances:...
800: Why use the option "reset model"? Why use the option "reset model"? Clear the model history When saving a model as an M-file it contains by default all the command history....
796: Problem with import of DXF files I have a problem with importing DXF files to COMSOL. What could be wrong? To be able to utilize the automatic mesh generation, COMSOL requires a...
786: Where can I purchase COMSOL Multiphysics? Where can I purchase COMSOL Multiphysics? To purchase COMSOL Multiphysics, please contact your nearest sales office.
768: 3D slice plot of arbitrary shape Is it possible to get a slice plot at some other angle, i.e. not parallel to the coordinate planes? Can I even change its shape? The standard way...
125: Integration over arbitrary cross section The COMSOL Multiphysics GUI provides the Domain Plot Parameters dialog box for plotting an expression on any given cross section of a subdomain or...
124: Creating a COMSOL Multiphysics curve object from a 2nd degree... The COMSOL Script function beziercurve2 creates a 2D Bezier curve given two control points and their respective weights. If you prefer to specify...
120: Meshing a thin geometry Sometimes the geometry for a problem can be very thin in one direction. Since the COMSOL Multiphysics free meshing by default creates...
114: Plot of contour lines on different surface plots in 2D and 3D How do I plot contour lines on slice plots, surface plots in 2D, isosurface plots, and on my boundary plots? Use the function postcontonsurf, which...
107: Command line associative geometry Associative geometry is a method that COMSOL Multiphysics uses in the graphical user interface to associate physics, mesh and other settings to the...
103: Convergence problems at high reaction rates (large source terms) Problems with high reaction rates (high Ri), or more generally, large source terms, may result in convergence problems. You may for instance get...

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