Repairing the Resonator and Transforming the Exhaust Tip

After you import the exhaust geometry, you use the tools in 3D-CAD to convert the Resonator part to a solid body. Then, you create two coordinate systems and use a transform operation to move the exhaust tip to its original position.

  1. In the Vis toolbar, click (Save-Restore-Select Views) and set Projection Mode to Parallel.
  2. In the toolbar at the top of the 3D-CAD View scene, click (Model Visibility) and activate the All Edges option. Also, change (Color Mode) to (Gray Color).
    The image below shows two parts displayed in brown indicating that they are sheet bodies.

Before repairing these parts, it is good practice to check the validity of the bodies. To run a validity check:
  1. At the top of the 3D-CAD tree, right-click the Exhaust node and select (Check Validity).
    A message with the results of the validity check is printed in the Output window:
    All bodies of model are valid.
  2. To convert the Resonator part to a solid body:
    1. Under the Body Groups node, right-click the Resonator node and select Sew.
    2. In the Sew Sheet Bodies panel, click OK.
    After executing the operation, the resonator part turns gray in the graphics window. The gray color indicates that the part is now a solid body.
In this tutorial one of the exhaust tips is misplaced. In order to move the part back to its original position at the end of one branch of the tail pipe, you must create two coordinate systems and then use a transform operation to move it.

To move the exhaust tip to its original position:

  1. First, create the coordinate system for the target location:
    1. Find the center point on the open branch of the Tail Pipe. To do this, in the graphics window, select the inner edge (circle) of the open branch of the Tail Pipe, right-click and choose Reference Geometry > Point from Entity Center.


    2. In the Point From Entity Center panel, click OK.
    3. Create a reference plane across the end of the open branch of the Tail Pipe whose Z axis points in to the Tail Pipe. To do so, select the same edge as before, right-click and choose Reference Geometry > Plane from Curve.
    4. In the Plane from Curve panel, set Type to Fitting Plane and click OK.
    5. In the 3D-CAD tree, right-click the Features node and select Reference Geometry > Create Coordinate System > From Point and Plane.
    6. In the Coordinate System From Point and Plane panel, set Point to Point 1 and Plane to Plane 1. Click OK.
    7. Rename the node to Target CSys.
  2. Create a coordinate system for the initial location of the exhaust tip:
    1. Select the inner edge of the exhaust tip as shown in the following image.


    2. Right-click the inner edge and select Reference Geometry > Point from Entity Center. In the Point From Entity Center panel, click OK.
    3. Select the face on the inner end of the Exhaust Tip.


    4. Right-click the face and select Reference Geometry > Coordinate System From Point and Plane.
    5. In the Coordinate System From Point and Plane panel, set Point to Point 2, retain the plane selection, and click OK.
    6. Rename the node to Initial Exhaust Tip CSys.
  3. To implement the change of position for the exhaust tip:
    1. Under the Body Groups node, right-click the Exhaust Tip 2 body and select Transform > Coordinate System.
    2. In the Transform Bodies By Coordinate System panel, set the following properties:
      Property Coordinate System Source
      From Initial Exhaust Tip CSys
      To Target CSys
    3. Click OK.
The exhaust tip must be moved within the tail pipe by a small amount, along the Z-axis of the Target CSys.
  1. To move the exhaust tip:
    1. Under the Body Groups node, right-click Exhaust Tip 2 and select Transform > Translate.
    2. In the Translate Bodies panel, within Translation Definition, set Coordinate System Source to use the Target CSys for its Reference Coordinate System.
    3. Also within the panel, set Translation Vector to [0.0, 0.0, 0.005] m m m.
    4. Click OK.
  2. Under the Features node, multi-select the Point 1, Plane 1, Target CSys, Point 2, and Initial Exhaust Tip CSys nodes, right-click and select Hide.


3D-CAD allows you to organise features in the simulation tree by grouping them together. To group features:
  1. Within the Features node, multi-select the features from SewSheetBodies 1 to TransformBody 1, right-click and select Group.
  2. Rename the feature group to Resonator and Exhaust Tip Fixes.
  3. Save the simulation.