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Some Advanced Concepts in Discrete Aerodynamic Sensitivity AnalysisAn efficient incremental-iterative approach for differentiating advanced flow codes is successfully demonstrated on a 2D inviscid model problem. The method employs the reverse-mode capability of the automatic- differentiation software tool ADIFOR 3.0, and is proven to yield accurate first-order aerodynamic sensitivity derivatives. A substantial reduction in CPU time and computer memory is demonstrated in comparison with results from a straight-forward, black-box reverse- mode application of ADIFOR 3.0 to the same flow code. An ADIFOR-assisted procedure for accurate second-order aerodynamic sensitivity derivatives is successfully verified on an inviscid transonic lifting airfoil example problem. The method requires that first-order derivatives are calculated first using both the forward (direct) and reverse (adjoint) procedures; then, a very efficient non-iterative calculation of all second-order derivatives can be accomplished. Accurate second derivatives (i.e., the complete Hessian matrices) of lift, wave-drag, and pitching-moment coefficients are calculated with respect to geometric- shape, angle-of-attack, and freestream Mach number
Document ID
20010038441
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Taylor, Arthur C., III (Old Dominion Univ. Norfolk, VA United States)
Green, Lawrence L. (NASA Langley Research Center Hampton, VA United States)
Newman, Perry A. (NASA Langley Research Center Hampton, VA United States)
Putko, Michele M. (Old Dominion Univ. Norfolk, VA United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2001
Subject Category
Aerodynamics
Report/Patent Number
AIAA Paper 2001-2529
Meeting Information
Meeting: Computational Fluid Dynamics
Location: Anaheim, CA
Country: United States
Start Date: June 11, 2001
End Date: June 14, 2001
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Public Use Permitted.

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