You can optionally adjust the rendering properties of an injection region by right-clicking it in the Outline tree view and selecting Render > Properties, then using the Render Options dialog box.

The Injection Shape option (under Symbols > Symbol) applies only for injection regions that appear, in the 3D Viewer, as symbols; such injection regions have Injection Model (as set in the details view, on the Injection Details tab) set to one of the following options: Circular Hole, Cylindrical Hole, Axisymmetric Slot.

The Injection Shape option produces an outline showing the approximate shape of the hole, or axisymmetric slot, at each injection position.

The symbol locations and orientations are intended to give a visual indication of the injection region settings. They will not always be exactly representative of what the CFX-Solver calculates, particularly if the injection region is not located reasonably close to one of the specified 2D regions.

The center of the symbol is located at the specified injection position. It will not be projected onto a 2D or 3D region.

The symbol size is calculated from the applicable injection region settings, which can include Diameter, Slot Width, and Slot Pitch.

The symbol orientation is calculated from the applicable injection region settings.

When a Normal to Boundary Condition option is used, or the orientation is implicitly normal to the boundary (for example, a circular hole specified with an Injection Location Type option of Selected 2D Regions), the normal is calculated by projecting an injection position onto the selected 2D regions and using the surface normal at that projected point. Where the projection fails (for example, if the injection position is not close enough to the selected 2D regions), a default orientation is used just to show the specified injection position and size of the hole/slot. The CFX-Solver might fail to locate such a hole/slot on any surface, or it might successfully locate such a hole/slot on one of the selected 2D regions, depending on exactly how the injection position matches the selected 2D regions.

For injection regions with the Injection Location Type option set to Domain, a circular symbol is used if there is a Flow Direction specification, with the circle orientation representing the direction of the inlet flow. If there is no Flow Direction specification (for example, if the injection region is an outlet or if the settings do not otherwise include a Flow Direction specification), then a sphere of the specified diameter is used instead.

For injection regions of type Cylindrical Hole, the symbol represents the projection of the specified cylinder onto the selected 2D regions. If the hole direction is parallel or nearly parallel to the 2D regions, there is an injection region setup error and the symbol displayed will not accurately represent the hole projection. Although a nominal projection will be displayed (to help identify the setup error), the case will most likely fail to run in the CFX-Solver.

In some circumstances, the CFX-Solver uses rotational periodicity to relocate injection positions onto a domain. This relocation is not performed when calculating injection position symbols, so in these circumstances, some injection position symbols might appear significantly outside of the domain geometry in CFX-Pre even though they will be located inside the domain by the CFX-Solver.