30.6.1 Generating a Surface Integral Report

To obtain a report for selected surfaces of the area or mass flow rate or the integral, flow rate, sum, facet maximum, facet minimum, vertex maximum, vertex minimum, or mass-, area-, facet-, or vertex-averaged quantity of a specified field variable, use the Surface Integrals dialog box (Figure  30.6.1).

Reports Surface Integrals Set Up...

Figure 30.6.1: The Surface Integrals Dialog Box

The steps for generating the report are as follows:

1.   Specify which type of report you are interested in by selecting Area, Integral, Area-Weighted Average, Flow Rate, Mass Flow Rate, Mass-Weighted Average, Sum, Facet Average, Facet Minimum, Facet Maximum, Vertex Average, Vertex Minimum, or Vertex Maximum in the Report Type drop-down list.

2.   If you are generating a report of area or mass flow rate, skip to the next step. Otherwise, use the Field Variable drop-down lists to select the field variable to be used in the surface integrations. First, select the desired category in the upper drop-down list. You can then select a related quantity from the lower list. (See Chapter  31 for an explanation of the variables in the list.)

3.   In the Surfaces list, choose the surface(s) on which to perform the surface integration.

If you want to select several surfaces of the same type, you can select that type in the Surface Types list instead. All of the surfaces of that type will be selected automatically in the Surfaces list (or deselected, if they are all selected already).

Another shortcut is to specify a Surface Name Pattern and click Match to select surfaces with names that match the specified pattern. For example, if you specify wall*, all surfaces whose names begin with wall (e.g., wall-1, wall-top) will be selected automatically. If they are all selected already, they will be deselected. If you specify wall?, all surfaces whose names consist of wall followed by a single character will be selected (or deselected, if they are all selected already).

4.   Click Save Output Parameter.... The Save Output Parameter dialog box (Figure  30.3.2) will open where you will specify the name of the newly created output parameter, or overwrite an existing output parameter of the same type. The default report name format is report-type-n (e.g. surface-integral-1).

After the output parameter is created, it is listed in the Parameters dialog box. You can create any number of output parameters of this report type.

5.   Click on the Compute button. Depending on the type of report you have selected, the label for the result will change to Area, Integral, Area-Weighted Average, Flow Rate, Mass Flow Rate, Mass-Weighted Average, Sum of Facet Values, Average of Facet Values, Minimum of Facet Values, Maximum of Facet Values, Average of Surface Vertex Values, Minimum of Vertex Values, or Maximum of Vertex Values, as appropriate. The computed results will also be printed in the ANSYS FLUENT console window.

6.   To save the computed results to a file, click the Write... button and specify the filename in the resulting Select File dialog box.

Note the following items:

• Mass averaging "weights'' toward regions of higher velocity (i.e., regions where more mass crosses the surface).

• Flow rates reported using the Surface Integrals dialog box are not as accurate as those reported with the Flux Reports dialog box (described in Section  30.3).

• The facet and vertex average options are recommended for zero-area surfaces.