Issue link: https://resources.system-analysis.cadence.com/i/1472078
Preparation of Geometry Models for Mesh Generation and CFD Cadence is a pivotal leader in electronic design and computational expertise, using its Intelligent System Design strategy to turn design concepts into reality. Cadence customers are the world's most creative and innovative companies, delivering extraordinary electronic products from chips to boards to systems for the most dynamic market applications. www.cadence.com © 2022 Cadence Design Systems, Inc. All rights reserved worldwide. Cadence, the Cadence logo, and the other Cadence marks found at www.cadence.com/go/trademarks are trademarks or registered trademarks of Cadence Design Systems, Inc. All other trademarks are the property of their respective owners. 06/22 DB/JC/RS/WP-GMT-MDL/PDF 42. Owen, S., Shead, T.M., & Martin, S., "CAD Defeaturing Using Machine Learning," 28th International Meshing Roundtable, October 2019. 43. Benyo, T.L., "Project Integration Architecture (PIA) and Computational Analysis Programming Interface (CAPRI) for Accessing Geometry Data from CAD Files," NASA TM-2002-211358, AIAA paper no. 2002-0750, March 2002. Notes and Acknowledgments Thanks are due to J.P. Abelanet for suggestions made during reviews of this paper and Nigel Taylor whose prior publications with the authors contributed much to this document. Product names used herein are for identification purposes only and do not constitute an endorsement. All registered and unregistered trademarks used herein are property of their respective owners. Appendix: Geometry Modeling in the CFD Vision 2030 Study What does the CFD 2030 Vision Study say about geometry modeling and mesh generation for CFD? 1. "A much higher degree of automation in all steps of the analysis process is needed including geometry creation, mesh generation and adaptation,…" (pg 5). 2. "Current CFD workflows are often paced by the geometry preprocessing and grid generation phases, which are significant bottlenecks." [pg 8]. 3. "Numerical uncertainties in the results come from many sources, including approximations to geometry, grid resolution,…" [pg 8] 4. "In order to streamline and accelerate the entire CFD workflow and design process, the development of basic scalable pre- and post-processing methods must be addressed. This includes geometry representation and mesh generation on the front end…" [pg 11] 5. "Given a suitable geometry representation and a desired level of solution accuracy, a fully automated meshing capability would construct a suitable mesh and adaptively refine this mesh throughout the solution process with minimal user intervention until the final accuracy levels are met." [pg 15] 6. "Inadequate Linkage with CAD" a. "there is currently no single standard for representing surface or solid geometries within CAD tools, complicating efforts to fully automate the link between mesh generation and geometry definition." [pg 15] b. "many existing CAD geometry definitions are poorly suited for CFD analyses, either due to insufficient accuracy (non water-tight geometries often adequate for manufacturing purposes), or due to excessive detail not essential for the CFD analysis. This results in the need to incorporate specialized post-processing tools such as shrink-wrapping in the former case, and/or de-featuring techniques in the latter case. At the same time, additional information such as slope and curvature or even higher surface derivatives may be required for the generation of curved mesh elements suitable for use with higher-order accurate CFD discretizations." [pg 15] c. "for adaptive meshing purposes, tight coupling between the CFD software and geometry definition is required to enable low-overhead, on-demand, geometry surface information queries within the context of a massively parallel computing framework." [pg 15] d. "However, fundamental advances in computational geometry and other areas will be key to improving the reliability, robustness, and parallel scalability of mesh generation capabilities…" [pg 15] e. "Beyond the typical codification of the inputs and outputs of a particular physical simulation, standards for MDAO may need to include sensitivities, uncertainties, and overall description of the parameterization (possibly including the geometry itself) and the optimization problem." [pp 19-20]