GUM-B v2 Tutorial: Nozzle/Post Geometry
  • Create Grid Topology. We will create the topological faces for the grid,
    which are called Four Curve Faces. A face of a block can be a NURBS
    surface, a Four Curve Face, or a composite (more on composites later).
    You decide which would suit your needs to effectively model your geometry.
    A Four Curve Face can be projected over a single or multiple surfaces, i.e.
    a Carpet Face. Faces are create automatically or manually. If an undesirable
    face is created, select it and delete it. This will occur frequently if automatic
    creation is used. Manually, all four edges need to be selected.
    1. Goto Topology.
    2. Create all the four sided faces ("Build Faces" button).

      Change to view 0 to see the faces better.

      Note: The exit and entrance faces were not created since the four
      boundaries are all derived from NURBS surfaces. By default these are
      ignored.

    1. Manually create the entrance and exit faces of the nozzle.

      1. Select the four corresponding edges for the entrance, the circular
        region.
      2. Create the face ("Build Faces" button).

      1. Select the four corresponding edges for the exit, the rectangular
        region.

      1. Create the face ("Build Faces" button).

    1. Turn off the geometry.
      1. Select the eight NURBS surfaces.
      2. Depress the x key (light bulb "off" icon).

        This will put the faces in an off draw buffer. t key or toggle switch icon
        will swap the display between the draw buffers. If nothing is selected
        when the on or off is depressed, the item in the Target option is acted
        upon.

    1. Clean up unwanted surfaces. There are four surfaces that need to be
      deleted so as extra blocks do not get created and that the point
      propagation does not get confused on the correct path for the
      block-to-block connectivity. Two faces are derived from the four
      intersection curves at the nozzle side walls. The other two are due to
      the curves that make up the outer boundary of the O-grid topology
      corresponding to the intersection curves. You should be able to look
      through the post.

    1. Create the blocks ("Build Blocks" button).

      All six sided regions are detected and created into blocks. A shrunken
      block will appear where a block has been created. The message buffer
      will reflect how many have been created. View 06 will show the blocks
      and edges. The colors indicate direction. Yellow is the I direction, Cyan
      is J, Magenta is K.

    1. "Display Information & Set Orientation" will allow you to renumber and
      reorient the blocks.

      Setting the Display Information Block menu to "Direction" will allow you
      to determine the origin of the blocks by indicating which faces are the
      corresponding min and max, by displaying the text on the block faces.
      Blocks should always be created right handed. The reverse and swap operations
      will always keep the right handedness of the blocks. Once one of the blocks
      has been oriented correctly, this information can be propagated to the rest of
      the visible blocks, by selecting the block and depressing the "Propagate" button.
      To change the numbering of the blocks, you can either select them in order
      and indicate a starting ID_number or select one block at a time and specify
      the ID_number and depress "Set id" button.