Select Error indicator to specify an error indicator using an error expression, which you add to the Error expression table below using the Add (
) button. The error expression can be any expression, including field variables and their derivatives, defined in the domain. Select the Active check box for the error expressions that should be part of the error indicator. Use the Move Up (
), Move Down (
), and Delete (
) buttons as needed to rearrange and remove error expressions.
By default, the software automatically determines the order of decrease in equation residuals on basis of the shape function orders in the geometry. To specify a residual order manually, select the Residual order check box and specify a nonnegative integer in the accompanying field (available when Error estimate is L2 norm of error squared or Functional ).
From the Solution selection list, select which solution that should be used to evaluate error estimates:
Select Use last (the default for all study types except Eigenvalue) to use the last solution. Select Use first to use the first solution. Select All (the default for Eigenvalue studies) to use all solutions from that study.Select Manual to use a specific solution number that you specify as solution indices in the Indices field.
In the Weights field (only available when Solution selection is Manual or All ), enter weights as a space-separated list of positive (relative) weights so that the error estimate is a weighted sum of the error estimates for the various solutions (eigenmodes). The default value of 1, which means that all the weight is put on the first solution (eigenmode). That is, any omitted weight components are treated as zero weight.
From the Adjoint solution error estimate list (only available when Error estimate is Functional ), select an error estimate method in the adjoint solution: a recovery technique or a gradient-based method. Select PPR for Lagrange (the default) to enforce using the recovery technique when possible, and select Gradient based to use the gradient-based method.
The Save solution on every adapted mesh check box is selected per default. Clear this check box if you do not want to save solution on every adapted mesh. In that case, the last two solutions are saved (the finest one and the second finest).
Under Mesh adaptation , the following settings are available.Use the Adaptation method list to control how to adaptively refine mesh elements. Select one of these methods:
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 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 you have selected to allow coarsening, specify the Maximum coarsening factor (a value of 5 by default) to scale the refined mesh size in the regions where refinement is not needed
Rebuild mesh , to set up a size expression describing the error and rebuild the meshing sequence using the size expression as input. Note that structured meshes, such as mapped and swept meshes, in general are not appropriately refined. This method is not supported on imported meshes. The size of the refined mesh is the minimum of the size of the original mesh (previous refined mesh) and the size defined by the refinement. Specify the Maximum coarsening factor (a value of 3 by default) to scale the refined mesh size in the regions where refinement is not needed.
Regular refinement , to make the solver refine elements in a regular pattern by bisecting all edges of an element that needs refinement.
Longest edge refinement , to make the solver refine only the longest edge of an element by recursively bisecting the longest edge of edge elements that need refinement. This method is less suitable for models with nonsimplex elements. This is the default method.
For all adaptation methods except Rebuild mesh , you can specify the maximum number of refinements of the mesh elements (default: 5) in the Maximum number of refinements field.
Use the Element selection list to specify how the solver should select which elements to refine. Select:
Rough global minimum to minimize 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 number of elements increases by about 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.
Use the Maximum number of elements field to specify the maximum number of elements in the refined mesh. If the number of elements exceeds this number, the solver stops even if it has not reached the number specified in the Maximum number of adaptations field. The default value is 10,000,000 (ten million) elements.
With the settings in the Goal-oriented termination list you or the physics interfaces can add a number of global goal-oriented quantities so that the mesh adaptation will terminate when these are stable to a requested accuracy instead of after a fixed number of adaptation iterations. Choose Off (the default), Auto , or Manual to control. You, when the list is set to Manual , or the physics, when the list is set to Auto , can add a number of global goal-oriented quantities, and the mesh adaptation will terminate when these are stable to a requested accuracy. These goal-oriented quantities could, for example, for an RF simulation be the S-parameters or another quantity of interest. The goal-oriented termination can be used with any of the available error estimation methods. When the Goal-oriented termination list is set to Manual , you can add goal-oriented terminal expressions in the table at the bottom of this section. Click the Add button () to add an expression (default: 1) that you can edit in the Goal-oriented termination expression column. If desired, adjust the tolerance (default: 0.01) in the Tolerance column, and the type of tolerance in the Tolerance type column: Relative (the default) or Absolute . Use the Active buttons to manage which goal-oriented termination expressions to include. The mesh adaptation will run until the relative changes for all expressions (applied individually for all expressions) go below their respective thresholds, unless the maximum number of adaptations limit is met, in which case the algorithm terminates with a warning.
Use the Maximum number of adaptations field to specify the maximum number of adaptive mesh refinement iterations. The default value is 5 in 1D, 2 in 2D, and 1 in 3D. With the Goal-oriented termination set to Auto , the default value is set to 20 in 1D, 15 in 2D, and 10 in 3D.
With the Goal-oriented termination set to Auto or Manual , you can control the display of convergence from the adaptation when the Output goal-oriented termination increments check box is selected. It is possible to choose the plot window to display the convergence as well as the table to be used by the plot from the Plot window — select New window (the default) or Graphics — and Output table lists, respectively. If you choose New from the Output table list, two new tables are created, one for the adaptation convergence plot and one for providing verbose information.
Also choose the level of detail for the log from the Goal-oriented termination log list: Minimal , Normal (the default), or Detailed . Choose Detailed if you want to include the evaluations for all the parameters, frequencies, or eigenvalues in the log.
From the Geometric entity level list, choose the geometric entity on which you want to do adaptive mesh refinement: Entire geometry (the default), Domain , Boundary , or Edge (3D only). For example, selecting Boundary can be useful if the model includes a physics interface defined on boundaries (surfaces) and you want to base the adaptation on that physics interface. For all levels except Entire geometry , make a selection of the geometric entities to include using the Selection list and selection tools below.
Select the Auxiliary sweep check box to enable an auxiliary parameter sweep, which corresponds to a Parametric solver attribute node. For each set of parameter values, the chosen Sweep type is solved for. This is available for Stationary, Time Dependent, and Frequency Domain studies.
Select a Sweep type to specify the type of sweep to perform:Specified combinations (the default) solves for a number of given combinations of values as given for each parameter in the list. The parameter lists are combined in the order given, that is, the first combination contains the first value in each list, the second combination contains all second values, and so on.
All combinations solves for all combinations of values; that is, all values for each parameter are combined with all values for the other parameters. Using all combinations can lead to a very large number of solutions (equal to the product of the lengths of the parameter lists).
In the table, specify the Parameter name , Parameter value list , and (optional) Parameter unit for the parametric solver. Click the Add button (
) to add a row to the table. When you click in the Parameter value list column to define the parameter values, click the Range button (
) to define a range of parameter values. The parameter unit overrides the unit of the global parameter. If no parameter unit is given, parameter values without explicit dimensions are considered dimensionless.
An alternative to specifying parameter names and values directly in the table is to specify them in a text file. Use the Load from File button () to browse to such a text file. The read names and values are appended to the current table. The format of the text file must be such that the parameter names appear in the first column and the values for each parameter appear row-wise with a space separating the name and values and a space separating the values.
Click the Save to File button () to save the contents of the table to a text file (or to a Microsoft Excel Workbook spreadsheet if the license includes LiveLink™ for Excel ® ).
Loading and saving the parameter table data using Excel include the units in the Parameter unit column. The unit column is ignored when saving and loading parameter data to *.txt, *.csv, and *.dat files.
For a Stationary or Frequency Domain study, select an option from the Run continuation for list: No parameter or one of the parameters given in the list.
