Table of Contents
Intersected Component Wireframes
This installment of the Cart3D tutorial will walk through the process of generating an intersected component wireframe in VSP. If you haven't built the Onera M6 wing, or you don't have your own geometry to analyze, you should go back to the geometry generation phase of the tutorial or you can download a ready-to-go Onera M6 geometry from the VSP Hangar.
Generating an Intersected Component Wireframe
As you proceed through the tutorial to mesh the Onera M6, remember that images have been included as thumbnails, so any place you see a picture, click on it for a larger version.
- Onera M6 start
- Refine airfoil points
- The triangulated wireframe is created by connecting the diagonals of the quadrilateral wireframe shown on screen. Consequently, the resolution of the triangulated wireframe is determined by the resolution of the quadrilateral wireframe shown on screen.
- As discussed in the Mesh Generation discussion of the tutorial, Cart3D has unique mesh resolution and quality requirements which make it particularly well suited to VSP and this approach.
- Refine spanwise wireframe
- Intersect components
- VSP has the ability to intersect the triangulated wireframe components resulting in a single watertight body for a model. In addition to providing input for high-fidelity analysis, this capability is commonly used to quickly calculated the wetted areas and volumes of a model.
- When the 'Comp Geom' window opens, click 'Execute' at the bottom of the window.
- When complete, a wetted area and volume report will be displayed in the 'Comp Geom' window; this window can now be closed. Notice in the 'Geom Browser' that VSP also added an intersected component mesh to the model. The mesh shown on screen exactly corresponds to the information written to the file. Note that the original geometry components are still present, but they have automatically been hidden.
- Export intersected file
- An intersected triangulated surface can be exported from VSP after CompGeom has been executed.
Generating an Intersected Wireframe from the Command Line
The VSP interface is the best way to set up and adjust the wireframe resolution, but once that is established, you may want to generate the wireframe from the command prompt.
To generate an intersected triangulated wireframe from the command line, enter the following command:
vsp -batch infile.vsp -compgeom -tri
vsp -batch infile.vsp -compgeom -stl
These commands will generate the unintersected wireframe and write 'infile.tri' or 'infile.stl', respectively.
Once the intersected wireframe is complete, the next step is to prepare the file for analysis in Cart3D. If you are using a STL file, it will need to be converted to a Cart3D TRI file; that process is detailed in the STL to TRI Tutorial. Otherwise, continue to the Cart3D Setup Tutorial.
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- Intersected Component Wireframe (This Page)