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Computational aspects of unsteady flowsThe calculation of unsteady flows and the development of numerical methods for solving unsteady boundary layer equations and their application to the flows around important configurations such as oscillating airfoils are presented. A brief review of recent work is provided with emphasis on the need for numerical methods which can overcome possible problems associated with flow reversal and separation. The zig-zag and characteristic box schemes are described in this context, and when embodied in a method which permits interaction between solutions of inviscid and viscous equations, the characteristic box scheme is shown to avoid the singularity associated with boundary layer equations and prescribed pressure gradient. Calculations were performed for a cylinder started impulsively from rest and oscillating airfoils. The results are presented and discussed. It is conlcuded that turbulence models based on an algebraic specification of eddy viscosity can be adequate, that location of translation is important to the calculation of the location of flow separation and, therefore, to the overall lift of an oscillating airfoil.
Document ID
Document Type
Conference Paper
Cebeci, T. (Douglas Aircraft Co., Inc. Long Beach, Calif., United States)
Carr, L. W. (NASA Ames Research Center Moffett Field, CA, United States)
Khattab, A. A. (NASA Ames Research Center Moffett Field, CA, United States)
Schimke, S. M. (NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 12, 2013
Publication Date
November 1, 1985
Publication Information
Publication: AGARD Unsteady Aerodynamics-Fundamentals and Applications to Aircraft Dynamics
Subject Category
Funding Number(s)
CONTRACT_GRANT: F496720-82-C-0055
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