Toward Automatic Grid Generation Si Loi Leung. Mechanical Engineering Mentor: Dr. Nathan Prewitt...
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Transcript of Toward Automatic Grid Generation Si Loi Leung. Mechanical Engineering Mentor: Dr. Nathan Prewitt...
![Page 1: Toward Automatic Grid Generation Si Loi Leung. Mechanical Engineering Mentor: Dr. Nathan Prewitt University of Hawaii.](https://reader030.fdocuments.in/reader030/viewer/2022032523/56649d805503460f94a64ac4/html5/thumbnails/1.jpg)
Toward Automatic Grid Generation
Si Loi Leung
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Mechanical Engineering
Mentor: Dr. Nathan Prewitt
University of Hawaii
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Project Goals
• Write a program to generate shape structure graphs for any given boundaries
• Investigate how it could possibly be employed in automatic grid generation of any arbitrary boundaries
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Outline
• How to create shape structure graphs
• Evaluation of the shape structure graphs
• A look at the medial axis
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Grid Generation
![Page 6: Toward Automatic Grid Generation Si Loi Leung. Mechanical Engineering Mentor: Dr. Nathan Prewitt University of Hawaii.](https://reader030.fdocuments.in/reader030/viewer/2022032523/56649d805503460f94a64ac4/html5/thumbnails/6.jpg)
Getting Complicated
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Multi-Block Topology
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Shape Structure Graphs
• Idea started from an article by Vitaly Ablavsky in the C/C++ Users Journal
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Voronoi DiagramThe Voronoi diagram of a collection of nodes is a partition of space into cells, where any point within a cell is closer to its respective node than to any others.
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Voronoi in Action
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Medial AxisThe medial axis is the collection of center points of circles that touch the boundary at least twice.
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Medial Axis in Action
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Medial Axis in Action
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Shape Structure Graph
The shape structure graph is a meta-graph with respect to the medial axis and retains only the “interesting” vertices.
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Shape Structure Graph
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Easymesh/Showmesh
Easymesh
• Bojan Niceno
• Generates two-dimensional unstructured meshes
• Showmesh is a graphical interface to show the results
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Input
50: 0 0 5 11: 5 0 5 1 2: 5 2.5 5 2 3: 3.5 4 5 24: 0 4 5 1# x y scale marker
50: 0 1 11: 1 2 22: 2 3 33: 3 4 44: 4 0 5# a b marker
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Output3
0: 0 3 4 -1 -1 1 5 6 4 2.5000 .25000 -1
1: 0 2 3 2 -1 0 4 2 1 2.4167 1.4167 -1
2: 3 1 2 -1 1 -1 3 1 0 1.7500 2.0000 -1
------------------------------------------------------------------------
e: i, j, k, ei, ej, ek, si, sj, sk xV, yV sign
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samples
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Evaluation
• Shape structure graph?
• Medial axis graph?
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TopMaker
• By David L. Rigby, QSS Group
• Technique to generate multi-block topologies using the medial axis
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How to Divide
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Creating the Multi-block Topology
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Something Like This
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Conclusion
• Work in progress• What I learned
– C/C++
– Linux
– CFD
• Acknowledgement– Dr. Nathan Prewitt
– PET staff
– PET interns
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Thank You