Solver
Performing a Mesh Refinement Study
Solution Number: 1261 Versions: All versionsHow do I gain confidence in the accuracy of the solution to my problem? How do I perform a mesh refinement study? All of the numerical methods used within COMSOL Multiphysics® discretize the modeling space via a Mesh ...
What to do when a linear stationary model is not solving
Solution Number: 1260 Versions: All versionsI 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 ...
Understanding the Fully Coupled vs. Segregated approach and Direct vs. Iterative Linear Solvers
Solution Number: 1258 Versions: All versionsHow, 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 versionsI 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 ...
Reducing the amount of solution data stored in a model
Solution Number: 1255 Versions: All versionsMy 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 versionsI 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 ...
Solving Wave-Type Problems with Step Changes in the Loads
Solution Number: 1244 Applies to: COMSOL Multiphysics Versions: All versionsI 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 ...
Running parametric sweeps, batch sweeps, and cluster sweeps from the command line
Solution Number: 1250 Versions: All versionsThis solution describes how to launch a parametric sweep, a batch sweep, or a cluster sweep simulation in COMSOL Multiphysics® from the command line. ## Short Summary Model methods are presented as a concept to ...
Solving Models with Step Changes to Loads in Time
Solution Number: 1245 Versions: All versionsHow should I model loads that change magnitude at a particular time? I am solving a transient model which has loads that change instantaneously in time, but the solver appears to be missing some of these changes in ...
Manually Setting the Scaling of Variables
Solution Number: 1240 Versions: All versionsThe default behavior of the software is to assume a different scaling for each set of variables in your model. These scale factors are by default automatically determined, but sometimes may need to be manually tuned. ...