GUM-B v2 Tutorial: Nozzle/Post Geometry
  • Create Wireframe representation of blocking. A four block O-grid around the
    post with a H-grid for and aft (6 blocks).
    1. Goto CAD Curves. Depress CAD or depress Curves.
    2. Create eight parametric lines from the end points of the intersection
      curves to the outer boundary of the nozzle side walls.
      1. Select an end point of one of the intersection curves.
      2. Select a point on the boundary of the nozzle side wall that the
        intersection lies in.
      3. Select the nozzle side wall. If you forget to select the side wall,
        see note below.
      4. Depress create line (line icon).

        Note : The icons indicate the required input and result. Functions are
        over loaded, so different inputs could invoke different functions.
        See help for further details.

      5. Repeat for seven other corners.

      Note: A pre-existing curve can be formed onto a surface by selecting the
      curve and the surface and selecting the form/project button (curve
      with arrows pointing to surface icon). Sample and control point option
      will determine the speed/accuracy of the forming. Either sample points or
      control points are mapped to the surface by using a shortest distance
      criterion. If a vector is selected, the curve will be sampled and rays
      will be projected to the surface or multiple surfaces.

    1. Create the opposing curves of a four sided region for the long side of
      the post intersection.
      1. Select the end points of the radiating curves to the boundaries.
        These points are on opposite boundaries not on the same boundary, they
        will be treated differently.
      2. Select the nozzle side wall.
      3. Create the line.
      4. Repeat three other times.

    1. Create four sided regions along the length or streamwise direction. This
      will be accomplished by spliting the streamwise boundaries into three
      pieces at the points that were used to create the radial lines for the
      intersection curves.
      1. Select the two points on the boundary edge the are the end points of
        two of the radial curves from the post intersections.

      1. Select the boundary edge.
      2. Depress split (scissors icon).

        Note : The boundary curve will not disappear, but three new curves
        should appear. If a space curve was used, it would be replaced by the
        new components.

      3. Repeat three other times.
    1. Create corresponding four sided regions for the top and bottom nozzle
      walls. See step 3 above.

    1. Create lines between the intersection curves of the side walls. This
      is a short cut since the post walls are straight. If the boundaries were
      not straight, the boundary edges would need to be split with the end
      points of the intersection curves or intersected with another curve. If
      split or intersected, the excess curves will need to be deleted. If they aren't,
      unnecessary faces can be created.