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F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel dataPressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.
Document ID
19910009738
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Fisher, David F.
(NASA Ames Research Center Moffett Field, CA., United States)
Banks, Daniel W.
(NASA Langley Research Center Hampton, VA., United States)
Richwine, David M.
(PRC Systems Services Co. Edwards, CA., United States)
Date Acquired
September 6, 2013
Publication Date
August 1, 1990
Subject Category
Aerodynamics
Report/Patent Number
NASA-TM-101724
NAS 1.15:101724
H-1633
AIAA PAPER 90-3018
Meeting Information
Meeting: AIAA 8th Applied Aerodynamics Conference
Location: Portland, OR
Country: United States
Start Date: August 20, 1990
End Date: August 22, 1990
Accession Number
91N19051
Funding Number(s)
PROJECT: RTOP 505-60-21
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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