Viscous effect on airfoils for unsteady transonic flows

Lee, S. C.

The viscous effect on aerodynamic performance of an arbitrary airfoil executing low frequency maneuvers during transonic flight was investigated. The small disturbance code, LTRAN2, was modified by using a conventional integral method, BLAYER, for the boundary layer and an empirical relation, viscous wedge, for simulating the suddenly thickened boundary layer behind the shock. Before the shock, only the boundary layer displacement thickness was evaluated. After the shock, the empirical wedge thickness was superimposed on the boundary layer thickness along the surface as well as in the wake region. The pressure coefficients were calculated for both steady and unsteady states. The viscous solution takes fewer iterations to obtain the converged steady state solution. Comparisons made with experimental data and the inviscid solution show that the viscous solution agrees better with the experimental data with about the same (or slightly less) amount of computational time.

Document ID

19820020375

Acquisition Source

Legacy CDMS

Document Type

Contractor Report (CR)

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Date Acquired

September 4, 2013

Publication Date

June 1, 1982

Subject Category

Report/Patent Number

Accession Number

82N28251

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Public

Work of the US Gov. Public Use Permitted.

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