Effect of angle of attack on boundary-layer transition at Mach 21

AIAA Journal ◽  
1971 ◽  
Vol 9 (6) ◽  
pp. 1203-1205 ◽  
Author(s):  
MICHAEL C. FISCHER ◽  
DAVID H. RUDY
Keyword(s):  
Boundary Layer ◽  
Angle Of Attack ◽  
Boundary Layer Transition ◽  
Layer Transition

Roughness, bluntness, and angle-of-attack effects on hypersonic boundary-layer transition

1966 ◽  
Vol 24 (1) ◽  
pp. 1-31 ◽  
Author(s):  
H. T. Nagamatsu ◽  
B. C. Graber ◽  
R. E. Sheer
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Surface Roughness ◽  
Reynolds Number ◽  
Mach Number ◽  
Angle Of Attack ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Number Range ◽  
Transfer Data

An investigation was conducted in a hypersonic shock tunnel to study the laminar boundary-layer transition on a highly cooled 10° cone of 4 ft. length over the Mach-number range of 8·5 to 10·5 with a stagnation temperature of 1400 °K. The effects on transition of tip surface roughness, tip bluntness, and ± 2° angle of attack were investigated. With fast-response, thin film surface heat-transfer gauges, it was possible to detect the passage of turbulent bursts which appeared at the beginning of transition. Pitot-tube surveys and schlieren photographs of the boundary layer were obtained to verify the interpretation of the heat-transfer data. It was found that the surface roughness greatly promoted transition in the proper Reynolds-number range. The Reynolds numbers for the beginning and end of transition at the 8·5 Mach-number location were 3·8 × 106−9·6 × 106and 2·2 × 106−4·2 × 106for the smooth sharp tip and rough sharp tip respectively. The local skin-friction data, determined from the Pitot-tube survey, agreed with the heat-transfer data obtained through the modified Reynolds analogy. The tip-bluntness data showed a strong delay in the beginning of transition for a cone base-to-tip diameter ratio of 20, approximately a 35% increase in Reynolds number over that of the smooth sharp-tip case. The angle-of-attack data indicated the cross flow to have a strong influence on transition by promoting it on the sheltered side of the cone and delaying it on the windward side.

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