All Solutions

What to do when a linear stationary model is not solving

Solution Number: 1260 Versions: All versions

I am solving a linear stationary finite element model but the software is not solving. Why? What can I do about this? A linear finite element model is one in which all of the material properties, loads, boundary ...


How can I see the equations COMSOL is defining? How do I implement a user-defined Multiphysics coupling?

Solution Number: 1259 Versions: All versions

I would like to define my own customized coupling between two existing physics interfaces. How can I do this? How can I find the names of the variables that I will need to use? How can I see the names of all ...


Understanding the Fully Coupled vs. Segregated approach and Direct vs. Iterative linear solvers

Solution Number: 1258 Versions: All versions

How, and why, switch between a fully coupled and a segregated approach to solving a multiphysics model? How, and why, switch between the direct and iterative linear system solver? ## Fully Coupled versus Segregated ...


Solving electromagnetic heating models with high-frequency loads

Solution Number: 1257 Versions: All versions

I am solving a Multiphysics problem involving electromagnetics and heat transfer. The electromagnetic fields are varying at a constant frequency, and the period is very short compared to the timespan over which the ...


I get an error message when trying to open my glTF-file in an external viewer

Solution Number: 1256 Versions: 5.4

After exporting a glTF-file from my COMSOL Multiphysics model, I get an error message when I try to open it in an external viewer. The most probable cause for this issue is that the external glTF-file you are using ...


Reducing the amount of solution data stored in a model

Solution Number: 1255 Versions: All versions

My models contain a lot of solution data, and I do not want my file sizes to get too large, it takes a lot of disk space. What can I do to reduce file size? Will this reduce the time it takes to solve the model? File ...


Controlling the Time Dependent solver timesteps

Solution Number: 1254 Versions: All versions

I am solving a transient model and changed the stepsize in the Times: field in the Study Settings, but the solver is still taking exactly the same timesteps. It seems the timesteps that the solver is taking are not ...


When the primary server for our license server triad crashes, license handling does not work.

Solution Number: 1253 Applies to: COMSOL Multiphysics Versions: 5.3, 5.3a, 5.4

When using a three-server redundancy setup for hosting the license manager, license handling does not work correctly if the designated Primary server goes down. To work around this, make sure that the license manager ...


Solving Wave-Type Problems with Step Changes in the Loads

Solution Number: 1244 Applies to: COMSOL Multiphysics Versions: All versions

I am solving a transient model and am expecting the solution to oscillate over time in response to step changes in the loads. How should I set up such a model? What solver changes should I make? Certain models will ...


License error -5,414 in COMSOL Multiphysics

Solution Number: 1252 Versions: 5.4, 5.5

In COMSOL Multiphysics 5.5, I receive some or all of the following error messages: The license could not be validated No such feature exists Feature: SERIAL License Path: C:\...\license.dat FlexNet licensing error:-5 ...