28.10 Transforming Surfaces

You can create a new data surface from an existing surface by rotating and/or translating the original surface. For example, you can rotate the surface of a complicated turbomachinery blade to plot data in the region between blades. You can also create a new surface at a constant normal distance from the original surface.

To transform an existing surface to create a new one, you will use the Transform Surface dialog box (Figure  28.10.1).

Surface $\rightarrow$ Transform...

Figure 28.10.1: The Transform Surface Dialog Box

The steps for transforming a surface are as follows:

1.   Select the surface to be transformed in the Transform Surface list.

2.   Set the appropriate transformation parameters, as described below. You can perform any combination of translation, rotation, and "isodistancing'' on the surface.

• Rotation: To rotate a surface, you will specify the origin about which the rotation is performed, and the angle by which the surface is rotated.

  In the About box under Rotate, you will specify a point, and the origin of the coordinate system for the rotation will be set to that point. (The $x$, $y$, and $z$ directions will be the same as for the global coordinate system.) For example, if you specified the point (1,5,3) in 3D, rotation would be about the $x$, $y$, and $z$ axes anchored at (1,5,3). You can either enter the point's coordinates in the x,y,z fields or click on the Mouse Select button and select a point in the graphics window using the mouse-probe button. (See Section  29.3 for information about mouse button functions.)

  In the Angles box under Rotate, you will specify the angles about the $x$, $y$, and $z$ axes (i.e., the axes of the coordinate system with the origin defined under About) by which the surface is rotated. For 2D problems, you can specify rotation about the $z$ axis only.

• Translation: To translate a surface, you will simply define the distance by which the surface is translated in each direction. Set the x, y, and z translation distances under Translate.

• Isodistancing: To create a surface positioned at a constant normal distance from the original surface, you need to set only that normal distance between the original surface and the transformed surface. Set the value for d under Iso-Distance.

3.   If you do not want to use the default name assigned to the surface, enter a new name under New Surface Name. The default name is the concatenation of the surface type and an integer which is the new surface ID (e.g., transform-9). (If the New Surface Name you enter is the same as the name of a surface that already exists, ANSYS FLUENT will automatically assign the default name to the new surface when it is created.)

The surface name that you enter must begin with an alphabetical letter. If your surface name begins with any other character or number, ANSYS FLUENT will not accept the entry.

4.   Click on the Create button. The new surface name will be added to the Transform Surface list in the dialog box. (The original surface will remain unchanged.)

If you want to delete or otherwise manipulate any surfaces, click on the Manage... button to open the Surfaces dialog box. See Section  28.11 for details.