12.4.4. Streamline: Limits Tab

The Limits tab enables modification of the tolerance, segments, and maximum time settings.

 

12.4.4.1. Step Tolerance

The values for the streamline (location and direction) are calculated at points determined by the step tolerance mode. You can choose to have streamline elements calculated relative to the mesh (grid) or at absolute increments as shown in the table that follows:

 
12.4.4.1.1. Mode

The Mode setting has the following options:

OptionDescription

Grid Relative

Specifies that the streamline must lie within the specified fraction of the local grid cell size. Selecting Grid Relative means that the Tolerance is directly proportional to the mesh spacing. In areas where the mesh has been refined (such as areas where the flow pattern changes quickly), the Tolerance setting reduces the distance between streamline points proportionately. This in turn produces more accurate streamlines in these areas.

Absolute

Specifies that the calculation points for streamline elements must lie within the Tolerance distance specified.

 
12.4.4.1.2. Tolerance

The Tolerance setting specifies the accuracy of the path. As the Tolerance setting becomes finer, the accuracy increases but the calculation time increases.

 

12.4.4.2. Upper Limits

 
12.4.4.2.1. Max Segments

The Max Segments setting specifies the maximum number of segments allowed for a streamline before it ends.

 
12.4.4.2.2. Max Time

The Max Time setting specifies the maximum time allowed to pass before the streamline ends. A time of zero, in this case, represents infinite time (because zero would actually plot nothing).

 
12.4.4.2.3. Max Periods

The Max Periods setting is available only if the Cross Periodics check box is selected in the Geometry tab. This setting sets the number of times a streamline is able to pass through a periodic boundary.