Accession Number : ADP001945

Title :   Unsteady Viscous Transonic Flow Computations Using the LTRAN2-NLR Code Coupled with Green's Lag-Entrainment Method,

Corporate Author : NATIONAL AEROSPACE LAB AMSTERDAM (NETHERLANDS)

Personal Author(s) : Houwink,R.

Report Date : 1982

Pagination or Media Count : 8

Abstract : Results of unsteady inviscid and viscous transonic flow computations are presented and compared with experimental data for the NACA64A3006 airfoil with oscillating in pitch. The computations were performed using the NLR version of the NASA-Ames computer code LTRAN2, coupled with the lag-entrainment method of Green for a turbulent boundary layer. The computed effect of the boundary layer on the unsteady airloads (reduction of the magnitude and a positive phase shift) generally leads to a better agreement with experimental data. The remaining differences may be due to the low frequency small perturbation potential approximation, the weak interaction modelling and wall interference effects.

Descriptors :   *Transonic flow, Supercritical airfoils, Unsteady flow, Viscous flow, Turbulent boundary layer, Computations, Flaps(Control surfaces), Oscillation

Distribution Statement : APPROVED FOR PUBLIC RELEASE