Accession Number:

AD0844445

Title:

The Interaction Between Local Effects at the Shock and Rear Separation - A Source of Significant Scale Effects in Wind-Tunnel Tests on Aerofoils and Wings,

Descriptive Note:

Corporate Author:

NATIONAL PHYSICAL LAB TEDDINGTON (UNITED KINGDOM) AERODYNAMICS DIV

Report Date:

1968-09-01

Pagination or Media Count:

45.0

Abstract:

Attention is drawn to important restrictions to the range of applicability of the flow model developed in earlier work on shock-induced separation of turbulent boundary-layers on aerofoils and wings, and also corresponding restrictions to the conclusion then drawn that full-scale behaviour could readily be reproduced at low Reynolds numbers. These restrictions arise because the model of a bubble growing progressively from the foot of the shock towards the trailing edge does not include the interaction that sometimes occurs between the disturbance at the foot of the shock and a subsonic-type rear separation if one exists, or is incipient, in the continuous adverse gradient further downstream. Such interactions are shown to be of increasing importance at wind-tunnel scale as the possibilities of using thicker and more highly loaded wing sections develop and to introduce real difficulties in reproducing full-scale behaviour at low or moderate Reynolds numbers. Author

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE