Known limitations

3D magnetic fields (A–V formulation);

turbulence;

structural transient and frequency-response analysis;

contact;

probes;

animations;

acoustic boundary elements (BEM) and perfectly matched layers. Open acoustic domains use Spherical Wave Radiation, and the field beyond the mesh comes from the Exterior Field Calculation;

exterior field calculation in 2D planar models (it would need Hankel functions);

result filters, dataset joins, and Combined/Array datasets;

adaptive mesh refinement;

LiveLink-style CAD synchronisation;

the Application Builder;

reading or writing COMSOL .mph files.

Boundary-layer meshing is not exposed.

Library materials have constant properties at 20 °C, unless you enter an expression.

The physics-controlled mesh refines automatically only for laminar flow and acoustics.

With an incident plane wave the acoustic solution is the total field. The exterior field is then most accurate when integrated over the scatterer’s surface.

Coupling operators work in results, not inside the equations.

In the electrochemistry interfaces, there is no electrode (solid-phase) domain, total-current or total-power electrode condition, or double-layer capacitance.

The desktop has one light theme. The Graphics window has light, white and dark themes, with a separate theme for exported images.

F1 opens the help in the web browser. There is no Help window inside the desktop.

Recovery keeps the unsaved model and reuses the interrupted session’s solutions, but cannot continue a solve from where it stopped (COMSOL’s Continue).

The mouse wheel zooms. Hidden entities are reached with Up/Down or +/- (the wheel does not step through them).

A font size change takes effect at the next start.

Integrals over quadratic elements use linearized cells (about 0.1 % on smooth fields). Boundary fluxes from reaction loads, such as electrode currents and heat flows, are exact.

Units are checked and reported, but a value of the wrong unit is still used (its SI number), as in COMSOL.

A component uses another component’s results only through coupling operators (scalars), one way, evaluated once per study step.

Identity pairs give continuity for scalar fields (heat transfer, electrostatics, electric currents, coefficient-form PDE); solid mechanics, flow and transport do not use them yet.