An isosurface is a surface upon which
a particular variable has a constant value, called the level. For instance, an Isosurface of pressure would
be a surface consisting of all the points in the geometry where the
pressure took a value of 1.32e+05 Pa. In CFD-Post,
isosurfaces can be defined using any variable. You can also color
the isosurface using any variable or choosing a constant color.
The following characteristics of isosurfaces will be discussed:
Note: There are several ways to insert an isosurface:
From the menu bar, select Insert > Location > Isosurface.
From the toolbar, select Location > Isosurface.
Depending on the context, you may be able to perform an insert from the shortcut menu in the tree view.
Note: When you are creating an isosurface using a variable that is fundamentally discontinuous within a domain, some unexpected portions of the isosurface may appear near the discontinuity. A common example is a variable Theta that is discontinuous at 0° in a full 360° domain. In such a case, creating an isosurface for any value of Theta will result in two basic parts: the expected part of the isosurface that was defined by the Theta value that was selected; a spurious part that appears along the border between nodes with Theta values near 0° and nodes with Theta values near 360°. The spurious part should be ignored.
Note: When you are creating an isosurface (or another object such as a contour plot or a chart), and the range of the specified variable is discontinuous at any point in its domain, the resulting range may be different from what you expect it to be. For example, consider a case with a cylindrical domain in which you would expect the Theta value to have a minimum value of 0° and a maximum value of 360°. In reality, the range will depend on the vertices of the mesh and the Theta values of the vertices. For example, an extremely coarse mesh with only 10 equidistant nodes on the circumference with Theta values of 0°, 36°, 72°, 108°, 144°, 180°, 216°, 252°, 288° 324°, and 0°, will result in a range of 0° to 324° for Theta. If the nodes appear on Theta values of, for example, 10°, 46°, 82°, 118°, 154°, 190°, 226°, 298°, 334°, and 10°, then the range for Theta will be from 10° to 334°. Therefore, the exact range of Theta will be dependent on the mesh. Refining the mesh will cause the actual range to be more similar to the expected range.
Note: Isosurface locator face IDs and node numbering are typically altered by the use of multithreading (see Threading). As a result, sampled vector plots on isosurface locators might look different when generated with multithreading compared to when generated without multithreading. Multithreading has no effect on vector plots that place a vector at each and every node.
For details, see Domains.
The Variable setting specifies the variable that you want to plot.
Tip: Click the Location Editor 
to open the Variable Selector dialog box, which displays the complete list of available options.
For help on which field to select, see Hybrid and Conservative Variable Values.
You can change the color settings by clicking the Color tab; for details, see Color Tab.
To change the rendering settings, click the Render tab. For details, see Render Tab.
The View tab is used for creating or applying predefined Instance Transforms for a wide variety of objects.
For details on changing the view settings, see View Tab.