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Accession Number N20120012062
Title Boundary-Layer Instability Measurements in a Mach-6 Quiet Tunnel.
Publication Date Jun 2012
Media Count 28p
Personal Author A. Chou A. D. Abney C. A. C. Ward D. C. Berridge R. P. K. Luersen S. P. Schneider
Abstract Several experiments have been performed in the Boeing/AFOSR Mach-6 Quiet Tunnel at Purdue University. A 7 degree half angle cone at 6 degree angle of attack with temperature-sensitive paint (TSP) and PCB pressure transducers was tested under quiet flow. The stationary crossflow vortices appear to break down to turbulence near the lee ray for sufficiently high Reynolds numbers. Attempts to use roughness elements to control the spacing of hot streaks on a flared cone in quiet flow did not succeed. Roughness was observed to damp the second-mode waves in areas influenced by the roughness, and wide roughness spacing allowed hot streaks to form between the roughness elements. A forward-facing cavity was used for proof-of-concept studies for a laser perturber. The lowest density at which the freestream laser perturbations could be detected was 1.07 x 10(exp -2) kilograms per cubic meter. Experiments were conducted to determine the transition characteristics of a streamwise corner flow at hypersonic velocities. Quiet flow resulted in a delayed onset of hot streak spreading. Under low Reynolds number flow hot streak spreading did not occur along the model. A new shock tube has been built at Purdue. The shock tube is designed to create weak shocks suitable for calibrating sensors, particularly PCB-132 sensors. PCB-132 measurements in another shock tube show the shock response and a linear calibration over a moderate pressure range.
Keywords Boundary layer transition
Cross flow
Direct numerical simulation
Half cones
Heat transfer
Hypersonic boundary layer
Hypersonic wind tunnels
Low noise
Low reynolds number
Power spectra
Pressure sensors
Shock tubes
Temperature sensitive paints
Wind tunnel tests

Source Agency National Aeronautics and Space Administration
NTIS Subject Category 46B - Fluid Mechanics
51A - Aerodynamics
Corporate Author National Aeronautics and Space Administration, Hampton, VA. Langley Research Center.
Document Type Conference proceedings
Title Note N/A
NTIS Issue Number 1303
Contract Number N/A

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