Base de connaissances du support

Initial guess leads to undefined function value

Solution numéro: 1192 Se réfère à: COMSOL Multiphysics Versions: Toutes les versions

An error "Initial guess leads to undefined function value" occurs. This error message usually appears when you have set up an expression that returns “not a value”; that is, it is undefined for the initial condition ...

---

Maximum number of linear iterations reached

Solution numéro: 1193 Se réfère à: COMSOL Multiphysics Versions: Toutes les versions

An error "Maximum number of linear iterations reached" occurs. If you get this error, the iterative linear system solver did not converge due to a bad initial guess or a bad preconditioner. To avoid the error, increase ...

---

Singular Matrix

Solution numéro: 1194 Se réfère à: COMSOL Multiphysics Versions: Toutes les versions

An error "Singular matrix" occurs. The system matrix (Jacobian matrix or stiffness matrix) is singular, so the solver cannot invert it. Usually this means that the system is underdetermined. Check that all equations ...

---

License Error

Solution numéro: 1195 Se réfère à: COMSOL Multiphysics Versions: Toutes les versions

I receive a license error when installing, or launching, COMSOL Multiphysics, There are separate Knowledge Base entries for the most common error messages users experience. See the list under Related Issues below. If ...

---

'Command not found' or 'No such file or directory' error when starting the license manager on Linux

Solution numéro: 1199 Versions: Toutes les versions

When I try to start the license manager for COMSOL 5.0, or later, on my Linux distribution I get an error message saying: ./lmgrd: Command not found. or ./lmgrd: No such file or directory The license manager ...

---

Solving time dependent models with inconsistent initial values

Solution numéro: 1172 Versions: Toutes les versions

A common mistake when setting up transient models is to have initial conditions that are inconsistent with the loads and boundary conditions. This occurs most often when running transient fluid flow studies, but the ...

---

COMSOL Multiphysics crashes when trying to access the documentation

Solution numéro: 1178 Versions: 5.4, 5.3a, 5.3, 5.2a

COMSOL Multiphysics crashes when I try to access the documentation on my Linux Machine. With the release of COMSOL Multiphysics 5.4, the documentation will automatically be opened in an external web browser if ...

---

Improving Convergence of Nonlinear Stationary Models

Solution numéro: 103 Versions: Toutes les versions

Stationary (time-invariant) models with nonlinearities may converge very slowly. A nonlinearity can be introduced into the model either in the governing equation, or by making any of the material properties, loads, or ...

---

Error: Failed to Connect to Inventor LT

Solution numéro: 1167 Versions: Toutes les versions

When I try to synchronize the geometry between COMSOL and Inventor LT, the error message Failed to connect to Inventor. Please make sure Inventor is running. is displayed. Inventor LT does not support third party ...

---

Using Symmetries in COMSOL Multiphysics

Solution numéro: 1038 Versions: Toutes les versions

How do I take advantage of the symmetries in my COMSOL model? ##Using Symmetries to Reduce Model Size By using symmetries in a model you can reduce its size by one-half or more, making this an efficient tool for ...

---