William M. Chan, Ph.D.

Computer Scientist, NASA Ames Research Center (ARC)
Computational Aerosciences Branch
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William's primary areas of interest are in the development of algorithms and software for overset grid pre-processing and post-processing. He is the principal developer of many of the modules of the Chimera Grid Tools software package which has been distributed to over 1,100 organizations in U.S. government laboratories, industry and universities. His work at NASA Ames includes support of high-fidelity computational fluid dynamics simulations of numerous subsonic and vertical lift and takeoff (VTOL) vehicles, turbopumps and liquid rocket sub-systems, and a variety of vehicle configurations from the Space Shuttle, Constellation, and Space Launch System programs. William obtained his B.S. in Mathematics from Southampton University in the U.K., and M.S. and Ph.D. from the Mechanical Engineering Department of Stanford University.

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Research/Technical Interests

William's research interests include algorithm and software development for high-fidelity computational simulations on complex configurations using overset grid methods, efficient user-interface design, and software optimization. Recent work includes supporting the agency’s Revolutionary Vertical Lift Technology (RVLT) and Transformational Tools and Technologies (TTT) projects.

Professional Activities

Associate Fellow, AIAA
Member of AIAA Technical Committee for Meshing, Visualization and Computing Environment
Member of Technical and Organizing Committee of Symposium on Overset Composite Grids and Solution Technology

Publications

Chan, W. M., Chuen, A. M., Jensen, J. C., Schauerhamer, D. G., "Overset Structured Mesh Generation on Complex Configurations Using the EPOGS Toolset", AIAA Paper 2026-4121, AIAA Aviation Forum, San Diego, CA, June, 2026.
Hosseini, S. S., Chuen, A. M., Chan, W. M., Computational Aerodynamic Study of the Lift+Cruise VTOL Concept Vehicle Components, Transformative Vertical Flight 2024, Santa Clara, CA, Feb., 2024.
Chuen, A. M., Hosseini, S. S., Jensen, J. C., Chan, W. M., Aerodynamic Simulations for Complex Geometries Using Automatically Generated Structured Overset Meshes, AIAA Paper 2023-3602, AIAA Aviation Forum, San Diego, California, June, 2023.
Chan, W. M., Chuen, A. M., Pandya, S. A., Recent Developments in Automation of Overset Structured Mesh Generation, 15th Symposium on Overset Composite Grid and Solution Technology, Suffolk, Virginia, November 1-3, 2022.
Chan, W. M., Pandya, S. A., Chuen, A. M., Automation of Overset Structured Surface Mesh Generation on Boundary Representation Geometries, AIAA Paper 2022-3607, AIAA Aviation Forum, Chicago, Illinois, June, 2022.
Chuen, A. M., Chan, W. M., Overlap Preservation Using Loosely-Coupled Boundary Conditions for Body-Fitted Structured Overset Grids, AIAA Paper 2022-0216, AIAA SciTech Forum, January, 2022.
Chuen, A. M., Chan, W. M., Mesh Effects on Flow Solutions for a 2-D Multi-Element Airfoil Using Structured Overset Methods, AIAA Paper 2020-3222, AIAA Aviation Forum, June, 2020.
Chan, W. M., Pandya, S. A., Haimes, R., Automation of Overset Structured Surface Mesh Generation on Complex Geometries, AIAA Paper 2019-3671, AIAA Aviation Forum, Dallas, Texas, June, 2019.
Chan, W. M., Pandya, S. A., Haimes, R., Automated Domain Decomposition for Overset Structured Surface Grid Generation, 14th Symposium on Overset Composite Grid and Solution Technology, College Park, Maryland, October 1-4, 2018.
Chan, W. M., Strategies Toward Automation of Overset Structured Surface Grid Generation, AIAA Paper 2017-3451, 23rd AIAA Computational Fluid Dynamics Conference, June, 2017.
Chan, W. M., Best Practices on Overset Structured Mesh Generation for the High-Lift CRM Geometry, AIAA Paper 2017-0362, 55th AIAA Aerospace Sciences Meeting, January, 2017.
Yoon, S., Chan, W. M., Pulliam, T. H., Computations of Torque-Balanced Coaxial Rotor Flows, AIAA Paper 2017-0052, 55th AIAA Aerospace Sciences Meeting, January, 2017.
Chan, W. M., Progress in Automation of Overset Structured Surface Grid Generation, 13th Symposium on Overset Composite Grid and Solution Technology, Mukilteo, Washington, October 17-20, 2016.
Dalle, D. J., Rogers, S. E., Chan, W. M., Lee, H. C., Inviscid and Viscous CFD Analysis of Booster Separation for the Space Launch System Vehicle, AIAA Paper 2016-0797, 54th AIAA Aerospace Sciences Meeting, January, 2016.
Chan, W. M., Pandya, S. A., "Advances in Distance-Based Hole Cuts on Overset Grids", AIAA Paper 2015-3425, 22nd AIAA Computational Fluid Dynamics Conference, Dallas, Texas, June, 2015.
Rogers, S. E., Dalle, D. J., Chan, W. M., CFD Simulations of the Space Launch System Ascent Aerodynamics and Booster Separation, AIAA Paper 2015-0778, 53rd AIAA Aerospace Sciences Meeting, January, 2015.
Chan, W. M., Pandya, S. A., Assessment of Grid Connectivity Quality and Enhancements on Automatic Estimates on Hole Boundary Placement, 12th Symposium on Overset Composite Grid and Solution Technology, Atlanta, Georgia, October 6-9, 2014.
Chan, W. M., Pandya, S. A., "Efficient Creation of Overset Grid Hole Boundaries and Effects of Their Locations on Aerodynamic Loads", AIAA Paper 2013-3074, 21st AIAA Computational Fluid Dynamics Conference, San Diego, California, June, 2013.
Chan, W. M., Pandya, S. A., Recent Developments on the X-rays Approach to Hole-Cutting, 11th Symposium on Overset Composite Grid and Solution Technology, Dayton, Ohio, October 15-18, 2012
Chan, W. M., Kim, N., Pandya, S. A., "Advances in Domain Connectivity for Overset Grids Using the X-rays Approach", Paper ICCFD7-1201, 7th International Conference on Computational Fluid Dynamics, Big Island, Hawaii, July, 2012.
Katz, A., Wissink, A. M., Sankaran, V., Meakin, R. L., Chan, W. M., Application of Strand Meshes to Complex Aerodynamic Flow Fields, J. Comp. Phys., 230, Issue 17, 6512--6530, July, 2011.
Chan, W. M., "Developments in Strategies and Software Tools for Overset Structured Grid Generation and Connectivity", AIAA Paper 2011-3051, 20th AIAA Computational Fluid Dynamics Conference, Honolulu, Hawaii, June, 2011.
Kim, N., Chan, W. M., "Automation of Hole-Cutting for Overset Grids Using the X-rays Approach", AIAA Paper 2011-3052, 20th AIAA Computational Fluid Dynamics Conference, Honolulu, Hawaii, June, 2011.
Pandya, S., Chan, W. M., "Computation of Sectional Loads from Surface Triangulation and Flow Data", AIAA Paper 2011-3680, 20th AIAA Computational Fluid Dynamics Conference, Honolulu, Hawaii, June, 2011.
Chan, W. M., "Recent Developments in Chimera Grid Tools", 10th Symposium on Overset Composite Grid and Solution Technology, Moffett Field, California, September 20-23, 2010.
Chan, W. M., "Enhancements to the Hybrid Mesh Approach to Surface Loads Integration on Overset Grids", AIAA Paper 2009-3990, 19th AIAA Computational Fluid Dynamics Conference, San Antonio, Texas, June, 2009.
Kao, D. L., Chan, W. M., "OVERSMART - A Solution Monitoring and Reporting Tool for the OVERFLOW Flow Solver", AIAA Paper 2009-3998, 19th AIAA Computational Fluid Dynamics Conference, San Antonio, Texas, June, 2009.
Pandya, S., Chan, W., Kless, J., "Automation of Structured Overset Mesh Generation for Rocket Geometries", AIAA Paper 2009-3993, 19th AIAA Computational Fluid Dynamics Conference, San Antonio, Texas, June, 2009.
Wissink, A. M., Katz, A. J., Chan, W. M., Meakin, R. L., "Validation of the Strand Grid Approach", AIAA Paper 2009-3792, 19th AIAA Computational Fluid Dynamics Conference, San Antonio, Texas, June, 2009.
Chan, W. M., Overset Grid Technology Development at NASA Ames Research Center, Computers & Fluids, 38, 496--503, 2009.
Chan, W. M., "Enhancements to the Grid Generation Script Library and Post-Processing Utilities in Chimera Grid Tools", 9th Symposium on Overset Composite Grid and Solution Technology, State College, Pennsylvania, October 14-16, 2008.
Kao, D. L., Chan, W. M., OVERSMART - A Solution Monitoring and Reporting Tool for the OVERFLOW Flow Solver, 9th Symposium on Overset Composite Grid and Solution Technology, State College, Pennsylvania, October 14-16, 2008
Chan, W., Klopfer, G., Onufer, J., Pandya, S., "Proximity Aerodynamics Analyses for Launch Abort Systems", AIAA Paper 2008-7326, 26th AIAA Applied Aerodynamics Conference, Honolulu, Hawaii, August, 2008
Kiris, C. C., Kwak, D., Chan, W. M., Housman, J. A., "High-Fidelity Simulations of Unsteady Flow Through Turbopumps and Flowliners", Computers & Fluids , 37, 536--546, 2008
Meakin, R. L., Wissink, A. M., Chan, W. M., Pandya, S. A., Sitaraman, J., "On Strand Grids for Complex Flows", AIAA Paper 2007-3834, 18th AIAA Computational Fluid Dynamics Conference, Miami, Florida, June, 2007
Pandya, S., Onufer, J., Chan, W., Klopfer, G., "Capsule Abort Recontact Simulation", AIAA Paper 2006-3324, 24th AIAA Applied Aerodynamics Conference, San Francisco, California, June, 2006.
Chan, W. M., "CAD Interface, Strand Grid Technology, and Other New Developments in Chimera Grid Tools 2.0", in Proceedings of the 8th Symposium on Overset Composite Grid and Solution Technology, Houston, Texas, October, 2006
Kiris, C. C, Kwak, D., Chan, W. M., Housman, J. A., A High Fidelity Simulation of Unsteady Flow Through Turbopump and Flowliners, AIAA Paper 2006-0089, 44th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, January, 2006
Chan, W. M., "Advances in Software Tools for Pre-processing and Post-processing of Overset Grid Computations", in Proceedings of the 9thInternational Conference on Numerical Grid Generation and Field Simulations, San Jose, California, June, 2005
Ahmad, J. U., Pandya, S. A., Chan, W. M., Chaderjian, N. M., "Navier-Stokes Simulation of Air-Conditioning Facility of a Large ModernComputer Room", FEDSM 2005-77225, in Proceedings of the 2005 ASME Fluids Engineering Division Summer Meeting and Exhibition, Houston, Texas, June, 2005
Chan, W. M., "Advances in Chimera Grid Tools for Multi-Body Dynamics Simulations and Script Creation", in Proceedings of the 7th Symposium on Overset Composite Grid and Solution Technology, Huntington Beach, California, October, 2004
Gomez, R. J., Vicker, D., Rogers, S. E., Aftosmis, M. J., Chan, W. M., Meakin, R. L., and Murman, S., STS-107 Investigation Ascent CFD Support, AIAA Paper 2004-2226, 34th AIAA Fluid Dynamics Conference, Portland, Oregon, June, 2004
Murman, S., Chan, W. M., Aftosmis, M. J., Meakin, R. L., "An Interface for Specifying Rigid-Body Motions for CFD Applications", AIAA Paper 2003-1237, 41st Aerospace Sciences Meeting and Exhibit, January, 2003
Chan, W. M., Selected Topics in Overset Technology Development and Applications at NASA Ames Research Center, in Proceedings of the 6th Overset Composite Grid and Solution Technology Symposium, Fort Walton Beach, Florida, October, 2002
Kiris, C., Chan, W. and Kwak, D., A Three-Dimensional Parallel Time Accurate Turbopump Simulation Procedure Using Overset Grid Systems, Proceedings of the 2nd International Conference on Computational Fluid Dynamics, Sydney, Australia,July, 2002
Chan, W. M., Gomez, R. J., Rogers, S. E. and Buning, P. G., "Best Practices in Overset Grid Generation", AIAA Paper 2002-3191, 32nd AIAA Fluid Dynamics Conference, St. Louis, Missouri, June, 2002
Chan, W. M., "The OVERGRID Interface for Computational Simulations on Overset Grids", AIAA Paper 2002-3188, 32nd AIAA Fluid Dynamics Conference, St. Louis, Missouri, June, 2002
Chan, W. M. and Rogers, S. E., Chimera Grid Tools Software, Gridpoints - Quarterly Publication of the NAS Division, NASA Ames Research Center, Spring, 2001
Chan, W. M., Meakin, R. L. and Potsdam, M. P., CHSSI Software for Geometrically Complex Unsteady Aerodynamic Applications, AIAA Paper 2001-0593, January, 2001
Kiris, C., Kwak, D. and Chan, W. M., Parallel Unsteady Turbopump Simulations for Liquid Rocket Engines, Supercomputing 2000 Conference, Dallas, Texas, November, 2000
Chan, W. M., Progress in Rapid Overset Surface Grid Generation on Complex Configurations, in Proceedings of the 5th Overset Composite Grid and Solution Technology Symposium, University of California at Davis, Davis, California, September, 2000
Chan, W. M., "Overset Structured Hyperbolic Grid Generation on Triangulated Surfaces", AIAA Paper 2000-2245, AIAA Fluids 2000 Conference,Denver, Colorado, June, 2000
Chan, W. M. and Gomez, R. J., "Advances in Automatic Overset Grid Generation Around Surface Discontinuities", AIAA Paper 99-3303, in Proceedings of the AIAA 14th Computational Fluid Dynamics Conference, Norfolk, Virginia, 1999
Chan, W. M, Hyperbolic Methods for Surface and Field Grid Generation, CRC Handbook of Grid Generation, Eds. Thompson, Soni and Weatherill, CRC Press, 1998
Chan, W. M., A Unified Overset Grid Generation Graphical Interface and New Concepts on Automatic Gridding Around Surface Discontinuities, in Proceedings of the 4th Overset Composite Grid and Solution Technology Symposium, Army Research Lab., Aberdeen, Maryland, September, 1998
Chan, W. M., Innovative Software Streamlines Overset Grid Generation, NAS News, Vol. 3, No. 3, May-June, 1998
Buning, P. G., Jespersen, D. C., Pulliam, T. H., Chan, W. M., Slotnick, J. P., Krist, S. E., Renze, K. J., OVERFLOW User's Manual, Version 1.8, NASA Ames Research Center, Moffett Field, CA, February, 1998
Chan, W. M. and Meakin, R. L., "Advances Towards Automatic Surface Domain Decomposition and Grid Generation for Overset Grids", AIAA Paper 97-1979, in Proceedings of the AIAA 13th Computational Fluid Dynamics Conference, Snowmass, Colorado, 1997
Chan, W. M., Recent Software and Algorithm Developments in Surface Domain Decomposition, Grid Generation, and Flow Coefficient Computation for Overset Grids, in Proceedings of the 3rd Overset Composite Grid and Solution Technology Symposium, Los Alamos, November, 1996
Chan, W. M. and Buning, P. G., "User's Manual for FOMOCO Utilities - Force and Moment Computation Tools for Overset Grids", NASA TM 110408, July, 1996
Chan, W. M., and Buning, P. G., Surface Grid Generation Methods for Overset Grids, Computers and Fluids , 24 , No. 5, 509--522, 1995
Chan, W. M., and Buning, P. G., Zipper Grids for Force and Moment Computation on Overset Grids, AIAA Paper 95-1681, in Proceedings of the AIAA 12th Computational Fluid Dynamics Conference, San Diego, California, June, 1995
Chan, W. M., Recent Developments in Grid Generation and Force Integration Technology for Overset Grids, in Proceedings of the 2nd Overset Composite Grid and Solution Technology Symposium, Fort Walton Beach, Florida, October, 1994
Chan, W. M., and Buning, P. G., A Hyperbolic Surface Grid Generation Scheme and its Applications, AIAA Paper 94-2208, AIAA 25th Fluid Dynamics Conference, Colorado Springs, Colorado, 1994
Chan, W. M., Chiu, I. T., and Buning, P. G., "User's Manual for the HYPGEN Hyperbolic Grid Generator and the HGUI Graphical User Interface", NASA TM 108791, October, 1993
Chan, W. M., Shariff, K., and Pulliam, T. H., Instabilities of Two-Dimensional Inviscid Compressible Vortices, J. Fluid Mech. 253 , 173--209, 1993
Pearce, D. G., Stanley, S. A., Martin, F. W., Gomez, R. J., Le Beau, G. J., Buning, P. G., Chan, W. M., Chiu, I. T., Wulf, A., and Akdag, V., Development of a Large Scale Chimera Grid System for the Space Shuttle Launch Vehicle, AIAA Paper 93-0533, 1993
Chan, W. M., and Steger, J. L., Enhancements of a Three-Dimensional Hyperbolic Grid Generation Scheme, Appl. Math. and Comput. 51 , 181--205, 1992
Buning, P. G., Parks, S. J., Chan, W. M., and Renze, K. J., Application of the Chimera Overlapped Grid Scheme to Simulation of Space Shuttle Ascent Flows, in Proceedings of the 4th International Symposium on Computational Fluid Dynamics, Davis, California, USA, 1991
Parks, S. J., Buning, P. G., Steger, J. L., and Chan, W. M., Collar Grids for Intersecting Geometric Components Within The Chimera Overlapped Grid Scheme, AIAA Paper 91-1587 in Proceedings of the AIAA 10th CFD Conference, Honolulu, Hawaii, June, 1991
Chan, W. M., and Steger, J. L., A Generalized Scheme for Three-Dimensional Hyperbolic Grid Generation, AIAA Paper 91-1588 in Proceedings of the AIAA 10th CFD Conference, Honolulu, Hawaii, June, 1991

Presentations

Recent Developments on Automation of Overset Structured Mesh Generation, AMS Seminar Series, January 27, 2022.
New Features in Chimera Grid Tools Version 2.2, AMS Seminar Series, December 4, 2018.
Overset Mesh Generation for the High-Lift Common Research Model, AMS Seminar Series, March 9, 2017.
Developments in Efficient Mesh Connectivity for Overset Grids, AMS Seminar Series, August 13, 2015.
The OVERGRID Graphical User Interface in Chimera Grid Tools Part 1, AMS Seminar Series, May 13, 2014.
The OVERGRID Graphical User Interface in Chimera Grid Tools Part 2, AMS Seminar Series, May 20, 2014.
The OVERGRID Graphical User Interface in Chimera Grid Tools Part 3, AMS Seminar Series, May 29, 2014.

Awards

AIAA Meshing, Visualization, and Computational Environments Best Paper Award (co-author, 2022)
NASA Exceptional Achievement Medal (2016)
Federal Laboratory Consortium Far West Region Outstanding Commercialization Award (2009)
NASA Exceptional Service Medal (2009)
NASA Ames Honor Award - Commercialization Tech Transfer for Chimera Grid Tools (2004)
Army Aeroflightdynamics Director's Award for Contract Employee of the Year (1999)

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