Coordinate Systems Reference

Coordinate Systems Manager Right-Click Actions

New Block-Mapped
Executes the create block-mapped coordinate system action to add a new block-mapped coordinate system to the Coordinate Systems node. See Block-Mapped Coordinate Systems.

Local Coordinate Systems Reference

For defining a local coordinate system, Simcenter STAR-CCM+ accepts user inputs for the central axis direction and a vector on the orthogonal plane. Simcenter STAR-CCM+ attempts to compute normalized and orthogonal unit vectors that honors these inputs. If it cannot honor the inputs, Simcenter STAR-CCM+ computes a valid coordinate system but does not change the user inputs. To alert you that a problem with the user input exists, Simcenter STAR-CCM+ displays:

  • a warning badge on the coordinate system node
  • a red outline around the problematic input field(s)
  • a warning message in the Output window every time the coordinate system is used while in this state

When you specify input vectors, consider that:

  • Only simulation parameters are usable in input vector expressions (see Global Parameters).
  • There are three scenarios where the axis input or the plane input can be considered invalid:
    • It contains an invalid expression (that is, one that cannot be evaluated).
    • One or more of its components are divided by zero.
    • It is set to [0, 0, 0].
  • Additionally, the plane input can be considered invalid when it is parallel to the axis input (regardless of whether the plane input is an expression or a static value).

When the input is invalid, the coordinate system either uses the most recent valid values (for example, in the case of changes to a pre-existing coordinate system), or attempts to adjust your inputs to generate normalized and orthogonalized values. These automatic attempts may continue during the simulation session, particularly as the dependency (use of the coordinate system by other objects) changes.

Although the resulting axis values ultimately define a usable coordinate system, and the simulation will still run, the results are not guaranteed to be correct.

Local Coordinate System Right-Click Actions
Transform System
Transforms the coordinate system in a manner selected in the sub-menu:
Coordinate Transform
Activates a dialog for transforming the selected coordinate system in the same way as a given second coordinate system is transformed to a third one. See example in: Transform Coordinate System Workflow.
Translate
Activates a dialog for translating the coordinate system.
Rotate
Activates a dialog for rotating the coordinate system.
Duplicate System to
Creates a duplicate of the selected coordinate system with respect to a new reference coordinate system. The location and orientation of the coordinate system is unchanged compared to the original system—the origin and orientation of the selected coordinate system are recalculated with respect to the new reference system. See example in: Duplicate Coordinate System.
Cartesian and Body-Fitted Local Coordinate Systems Properties
X Axis Input
Specifies the X-axis direction.
Vector on X-Y Plane Input
Specifies a vector on the X-Y plane.
X Axis Direction
Y Axis Direction
Z Axis Direction
Cartesian unit vectors (read-only) that, along with the Origin, define the x, y, and z axes respectively. These unit vectors are calculated from the X Axis Input and the Vector on X-Y Plane Input. The unit vectors are guaranteed to be orthogonal and normalized even if they cannot honor the user inputs.
Origin
Specifies the Cartesian position vector defining the origin of the x-, y-, and z-axes.
Reference System
Displays the system to which the current coordinate system refers (read-only).
Cylindrical Coordinate System Properties
Radial Axis Input
Specifies the radial axis direction.
Vector on R-Theta Plane Input
Specifies a vector on the R-Theta plane.
Radial Axis Direction
Tangential Axis Direction
Axial Axis Direction
Cartesian unit vectors (read-only) that, along with the Origin, define the radial, tangential, and axial axes respectively. These unit vectors are calculated from the Radial Axis Input and the Vector on R-Theta Plane Input. The unit vectors are guaranteed to be orthogonal and normalized even if they cannot honor the user inputs.
Origin
Specifies the Cartesian position vector defining the origin of the radial, tangential, and axial axes.
Reference System
Displays the system to which the current coordinate system refers (read-only).
Spherical Coordinate System Properties
Radial Axis Input
Specifies the radial axis direction.
Vector on R-Theta Plane Input
Specifies a vector on the R-Theta plane.
Radial Axis Direction
Polar Axis Direction
Azimuthal Axis Direction
Cartesian unit vectors (read-only) that, along with the Origin, define the radial, polar, and azimuthal axes respectively. These unit vectors are calculated from the Radial Axis Input and the Vector on R-Theta Plane Input. The unit vectors are guaranteed to be orthogonal and normalized even if they cannot honor the user inputs.
Origin
Specifies the Cartesian position vector defining the origin of the radial, polar, and azimuthal axes.
Reference System
Displays the system to which the current coordinate system refers (read-only).

Block-Mapped Coordinate System Reference

Region
Displays a drop-down list of the regions in the simulation, from which you select a region to specify boundary groups.
Interpolation Points
Defines a set of points along the three dimensions, representing the number of cells in the background grid along the Umin/Umax, Vmin/Vmax, and Wmin/Wmax directions. Increasing the number of points improves the accuracy with which the coordinate system follows the contours of the mapped surfaces.