Creating a Sketch on a 3D-CAD Model

Creating a Sketch from Existing Edges

A face sketch is a sketch that comes from the edges of a planar face on existing bodies. To create a face sketch:
  1. Right-click on the target face in the 3D-CAD View scene and select Create Sketch > From Face Edges.
    Simcenter STAR-CCM+ activates sketch mode, and adds the edges that define the face to the sketch.

  2. If you intend to use the face edges for reference only, convert them to construction entities.
    • Multi-select the edges on the sketch, right-click, and choose Set As Construction.
  3. Add other sketch entities as required.
  4. When complete, click OK on the Sketch panel.

    A Sketch node is added to the feature tree.

Creating Equation-based Curves in 2D-Sketch

You can define curves directly by providing expressions for the X, Y coordinates. Using expressions allows you to define the curve point coordinates as function of specified parameters.

To create an equation-based 2D curve:

  1. Define the required interval design parameters and scalar design parameters for the equations (see Creating a New Design Parameter).

    For each component of the curve, define the equation directly in the Equation Base Curve dialog. The equations specified for the x and y components must contain an interval design parameter. The design parameters required to create a 2D sketch are Angle, Generic, andLength interval parameters. For more information, see Interval Design Parameters. You must use the interval parameters directly in the equations. The equation is not defined if the interval design parameter is defined in a separate design parameter.

  2. In the Sketch panel, click (Create Equation Based Curve).
  3. In the Create Equation Based Curve dialog, specify the X and Y, component equations using the Simcenter STAR-CCM+ expression syntax as well as the Interpolation Points.

    The interval range specified in the interval design parameter is split according to the number of Interpolation Points you specify. For each interpolation point the x and y coordinates are calculated using the equations specified. If you use a higher number of interpolation points, Simcenter STAR-CCM+ defines the curve with greater accuracy. Between each point of the curve a spline interpolation is used to connect the points.

    The x and y component equations can be exposed by clicking (Expose Design Parameter). For more information, see Exposing a Parameter. If you expose a parameter, do not use the exposed parameter in any other equation or scalar design parameter.

  4. If required, deactivate Zero Curvature At End Points.

    If activated, the option creates a natural spline with zero curvature at end points, otherwise the spline will have some curvature at end points. NACA curves and aero foil curves are created better when the Zero Curvature at End Points option is deactivated.

    For details on all equation-based curve properties, see Equation Based Curves Panel.

  5. To edit the curve, in the 3D-CAD View scene, right-click the curve and select Edit Equation Curve.
  6. To complete the 2D sketch, click OK.

Creating a Sketch at the Center of a Face

You can choose to place a sketch at the center of a face on an existing body. The center of the face is calculated and the origin is placed at this location.

To create a sketch at the center of a face:
  1. In the Graphics window, right-click the desired face and select Create Sketch > At Face Center.


    The sketch plane is placed on the selected face with the origin set to the center of the face.

  2. Draw the sketch entities.
  3. When complete, click OK.

    A Sketch node is added to the feature tree.