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Summary of Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases 2 to 5Results from the Sixth AIAA CFD Drag Prediction Workshop Common Research Model Cases 2 to 5 are presented. As with past workshops, numerical calculations are performed using industry-relevant geometry, methodology, and test cases. Cases 2 to 5 focused on force/moment and pressure predictions for the NASA Common Research Model wing-body and wing-body-nacelle-pylon configurations, including Case 2 - a grid refinement study and nacelle-pylon drag increment prediction study; Case 3 - an angle-of-attack buffet study; Case 4 - an optional wing-body grid adaption study; and Case 5 - an optional wing-body coupled aero-structural simulation. The Common Research Model geometry differed from previous workshops in that it was deformed to the appropriate static aeroelastic twist and deflection at each specified angle-of-attack. The grid refinement study used a common set of overset and unstructured grids, as well as user created Multiblock structured, unstructured, and Cartesian based grids. For the supplied common grids, six levels of refinement were created resulting in grids ranging from 7x10(exp 6) to 208x10(exp 6) cells. This study (Case 2) showed further reduced scatter from previous workshops, and very good prediction of the nacelle-pylon drag increment. Case 3 studied buffet onset at M=0.85 using the Medium grid (20 to 40x10(exp 6) nodes) from the above described sequence. The prescribed alpha sweep used finely spaced intervals through the zone where wing separation was expected to begin. Although the use of the prescribed aeroelastic twist and deflection at each angle-of-attack greatly improved the wing pressure distribution agreement with test data, many solutions still exhibited premature flow separation. The remaining solutions exhibited a significant spread of lift and pitching moment at each angle-of-attack, much of which can be attributed to excessive aft pressure loading and shock location variation. Four Case 4 grid adaption solutions were submitted. Starting with grids less than 2x10(exp 6) grid points, two solutions showed a rapid convergence to an acceptable solution. Four Case 5 coupled aerostructural solutions were submitted. Both showed good agreement with experimental data. Results from this workshop highlight the continuing need for CFD improvement, particularly for conditions with significant flow separation. These comparisons also suggest the need for improved experimental diagnostics to guide future CFD development.
Document ID
20170001397
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Tinoco, Edward N. (Retired Kent, WA, United States)
Brodersen, Olaf P. (Deutsches Zentrum fuer Luft- und Raumfahrt e.V. Braunschweig, Germany)
Keye, Stefan (Deutsches Zentrum fuer Luft- und Raumfahrt e.V. Braunschweig, Germany)
Laflin, Kelly R. (Textron Aviation Wichita, KS, United States)
Feltrop, Edward (Textron Aviation Wichita, KS, United States)
Vassberg, John C. (Boeing Co. Seattle, WA, United States)
Mani, Mori (Boeing Co. Huntington Beach, CA, United States)
Rider, Ben (Boeing Co. Saint Louis, MO, United States)
Wahls, Richard A. (NASA Langley Research Center Hampton, VA, United States)
Morrison, Joseph H. (NASA Langley Research Center Hampton, VA, United States)
Hue, David (Office National d'Etudes et de Recherches Aerospatiales Meudon, France)
Gariepy, Martin (Ecole Polytechnique Montreal, Quebec, Canada)
Roy, Christopher J. (Virginia Tech Blacksburg, VA, United States)
Mavriplis, Dimitri J. (Wyoming Univ. Laramie, WY, United States)
Murayama, Mitsuhiro (Japan Aerospace Exploration Agency Chofu, Japan)
Date Acquired
February 7, 2017
Publication Date
January 9, 2017
Subject Category
Aerodynamics
Report/Patent Number
NF1676L-26060
Meeting Information
Meeting: 2017 AIAA SciTech
Location: Dallas, TX
Country: United States
Start Date: January 9, 2017
End Date: January 13, 2017
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 432938.11.01.07.43.40.40
Distribution Limits
Public
Copyright
Public Use Permitted.

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