Accession Number : ADP001934

Title :   Application of Unsteady Laminar Triple-Deck Theory to Viscous-Inviscid Interaction from an Oscillating Flap in Supersonic Flow,


Personal Author(s) : Huang,Ming-Ke ; Inger,G. R.

Report Date : 1980

Pagination or Media Count : 8

Abstract : Unsteady triple-deck theory is applied to analyze the local viscous-inviscid interaction of an idealized oscillating flap with a laminar boundary layer in supersonic flow. For small flap amplitudes and small-to-moderate nondimensional frequencies, linearized analytical solutions by means of Fourier transformation are given for the pressure and shear distributions ahead of and behind the flap hinge. In the supersonic case, the predicted unsteady viscous effects reduce the pressure amplitude and spread it out upstream while causing it to lag the quasi-steady inviscid prediction (flap motion); this also results in an unsteady delay of incipient separation at the hinge to a higher flap amplitude. The unsteady upstream influence of the interaction is found to decrease as the frequency increases. These trends are shown to be in qualitative agreement with available experimental data. (Author)

Descriptors :   *Supersonic flow, Laminar boundary layer, Flaps(Control surfaces), Oscillation, Unsteady flow, Viscous flow, Inviscid flow, Interactions, Two dimensional, Steady state

Distribution Statement : APPROVED FOR PUBLIC RELEASE