For stationary and eigenvalue solvers, the Adaptive Mesh Refinement node cannot be added manually but is instead added by the solvers to indicate that they run an adaptive mesh refinement. The Adaptive Mesh Refinement node then only includes an Output section with information about the adaptation solutions and meshes.
|
•
|
The Time-interval length can be controlled manually or automatically. Select Manual (default) or Automatic. If Time-interval length is Automatic, the algorithm strives to assume the given value for the fraction of maximum refinement (default value: 0.2) by controlling the size of the time interval. A value of zero means no refinement of the base mesh and a value of one means refinement everywhere using the maximum element refinements. The shortening and lengthening of the interval is determined by the interval reduction and growth factors described below.
|
•
|
The value in the Interval reduction factor field (default value: 0.5) determines how the solver reduces the time interval length. A value of 0.5 makes the interval length half of the previous interval length when reduced.
|
•
|
By default, the solver determines the Interval length (unit: s) automatically (only available when Time-interval length is Manual) using an interval length that gives a total of 10 intervals. The length of the time interval is the simulation time before a refinement of the mesh takes place. Select the check box to specify a user-defined time interval length in the field (default value: 0.1 s).
|
•
|
The value in the Interval growth factor (only available when Time-interval length is Automatic) text field (default value: 2.0) determines how the solver increases the time interval length. A value of 2.0 makes the interval length twice as large as the previous interval length when increased.
|
•
|
By default, the solver determines the Initial interval length (unit: s) automatically (only available when Time-interval length is Automatic). The length of the initial time interval is the simulation time before the first refinement of the mesh takes place. Select the check box to specify a user-defined time interval length in the field (default value: 0.1 s).
|
•
|
By default, the solver also determines the Minimal interval length (unit: s) automatically. The minimal length of the time interval is the shortest possible simulation time without performing a mesh refinement. Click to select the check box to specify a user-defined minimal interval length in the field (default value: 0.01 s). The interval length is reduced according to the Interval reduction factor if the solver fails to converge with the current interval length, in which case the minimal interval length setting can be useful.
|
•
|
•
|
•
|
General modification, to use the current mesh as a starting point and modify it by refinements, coarsening, topology modification, and point smoothing. Use the Allow coarsening check box (selected by default) to control if mesh coarsening is used. If the mesh contains anisotropic elements (for example, a boundary layer mesh), it is best to disable mesh coarsening to preserve the anisotropic structure. If mesh coarsening is allowed, enter a Maximum coarsening factor (default: 5) if needed.
|
•
|
Rough global minimum to minimize the L2 norm of the error by refining a fraction of the elements with the largest error in such a way that the total number of elements increases roughly by the factor specified in the accompanying Element count growth factor field. The default value is 1.7, which means that the number of elements increases by roughly 70%.
|
•
|
Fraction of worst error to refine elements whose local error indicator is larger than a given fraction of the largest local error indicator. Use the accompanying Element fraction field to specify the fraction. The default value is 0.5, which means that the fraction contains the elements with more than 50% of the largest local error.
|
•
|
Fraction of elements to refine a given fraction of the elements. Use the accompanying Element fraction field to specify the fraction. The default value is 0.5, which means that the solver refines about 50% of the elements with the largest local error indicator.
|
Implementing a Point Source: Application Library path COMSOL_Multiphysics/Equation_Based/point_source.
|