Investigation of Flat-Plate Aspect Ratio Effects on Ramp-Induced, Adiabatic, Boundary-Layer Separation at Supersonic and Hypersonic Speeds
Final rept. 10 Dec 1969-25 Mar 1970
ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN
Pagination or Media Count:
An experimental investigation of the effects of flat-plate aspect ratio on both laminar and turbulent boundary-layer separations induced by ramps was conducted at free-stream Mach numbers of 6, 8, and 10. Reynolds numbers, based on flat-plate length, ranged from 0.06 million to 1.0 million laminar and from 2.6 million to 9.1 million turbulent at near-adiabatic model wall conditions. Local Mach number on the flat plate was varied by pitching the laminar model at all free-stream Mach numbers. Longitudinal surface pressure distributions at several spanwise stations were measured to define the lateral pressure gradients and the spanwise variation of the longitudinal extent of the separation region. Data are presented to support the conclusion that for a flat plate short enough 2.5 in. to achieve laminar flow reattachment, it is required that the flat-plate aspect ratio be of the order of 3 to be assured of negligible effects induced by the finite span.
- Fluid Mechanics