Physics-Controlled Meshing

When a physics-controlled sequence is built, a sequence of ordinary meshing features is created. This sequence can be customized by editing these features. However, do not assume the existence of a certain feature in a Java program designed to run with future versions of COMSOL Multiphysics. The actual contents of the sequence might change.

A physics-controlled meshing sequence examines the physics to automatically determine size attributes and sequence operations needed to create a mesh adapted to the problem. The physics-controlled sequence is based on heuristics and knowledge built-in by application experts. It is not adapted by numerical error estimates — that type of adaptation is provided by mesh adaptation in the solver sequence.

When a mesh is built or a problem solved, the physics-controlled sequence is updated to match the currently active physics. If the sequence is in any other state than physics-controlled, it is not updated or modified before it is built.

By default, a meshing sequence is in the physics-controlled state. If you manually add a feature to the sequence or edit a feature, the sequence automatically switches to the user-controlled state. It is also possible to explicitly switch to user-controlled state by entering

model.mesh(<tag>).automatic(false);

To switch back to physics-controlled mesh, enter

model.mesh(<tag>).automatic(true);

The current sequence is then modified or overwritten next time the sequence is built or the problem is solved.

Use model.mesh(<tag>).isAutomatic() to determine in which state the sequence is.

You can adjust the overall size of a physics-induced mesh by using the method

model.mesh(<tag>).autoMeshSize(<size>);

The value 5 of <size> corresponds to the default size, the values 4, 3, 2, and 1 give you an increasingly finer mesh, whereas the values 6, 7, 8, and 9 give you a coarser mesh. The method model.mesh(<tag>).autoMeshSize() returns the current size adjustment.