Observations on CFD Verification and Validation from the AIAA Drag Prediction WorkshopsThe authors provide observations from the AIAA Drag Prediction Workshops that have spanned over a decade and from a recent validation experiment at NASA Langley. These workshops provide an assessment of the predictive capability of forces and moments, focused on drag, for transonic transports. It is very difficult to manage the consistency of results in a workshop setting to perform verification and validation at the scientific level, but it may be sufficient to assess it at the level of practice. Observations thus far: 1) due to simplifications in the workshop test cases, wind tunnel data are not necessarily the “correct” results that CFD should match, 2) an average of core CFD data are not necessarily a better estimate of the true solution as it is merely an average of other solutions and has many coupled sources of variation, 3) outlier solutions should be investigated and understood, and 4) the DPW series does not have the systematic build up and definition on both the computational and experimental side that is required for detailed verification and validation. Several observations regarding the importance of the grid, effects of physical modeling, benefits of open forums, and guidance for validation experiments are discussed. The increased variation in results when predicting regions of flow separation and increased variation due to interaction effects, e.g., fuselage and horizontal tail, point out the need for validation data sets for these important flow phenomena. Experiences with a recent validation experiment at NASA Langley are included to provide guidance on validation experiments.
Document ID
20140007308
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Joseph H Morrison (Langley Research Center Hampton, Virginia, United States)
Bil Kleb (Langley Research Center Hampton, Virginia, United States)
John C Vassberg (Boeing (United States) Chicago, Illinois, United States)
Date Acquired
June 11, 2014
Publication Date
January 10, 2014
Publication Information
Publication: 52nd Aerospace Sciences Meeting
Publisher: American Institute of Aeronautics and Astronautics