In-Flight Transition Measurement on a 10 Degree Cone at Mach Numbers From 0.5 to 2.0
Fisher, David F. and Dougherty Jr., N. Sam (1982) In-Flight Transition Measurement on a 10 Degree Cone at Mach Numbers From 0.5 to 2.0. Technical Report NASA TP-1971, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
Boundary layer transition measurements were made in flight on a 10 degree transition cone tested previously in 23 wind tunnels. The cone was mounted on the nose of an F-15 aircraft and flown at Mach numbers from 0.5 to 2.0 and altitudes from 1500 meters (5000 feet) to 15,000 meters (50,000 feet), overlapping the Mach numer/Reynolds number envelope of the wind tunnel tests. Transition was detected using a traversing pitot probe in contact with the surface. Data were obtained near zero cone incidence and adiabatic wall temperature. Transition Reynolds number was found to be a function of Mach number and of the ratio of wall temperature to adiabatic wall temperature. Microphones mounted flush with the cone surface measured free-stream disturbances imposed on the laminar boundary layer and identified Tollmien-Schlichting waves as the probable cause of transition. Transition Reynolds number also correlated with the disturbance levels as measured by the cone surface microphones under a laminar boundary layer as well as the free-stream impact microphone. The experimental results and supporting data of this study are tabulated. The calibration data and the methods used to correct the data are provided in appendixes.
| EPrint Type: | NASA Technical Publication |
|---|---|
| Keywords: | Transition, Boundary Layer, Cones, Tollmien-Schlichting waves |
| Subjects: | (01 - 09) Aeronautics: (02) Aerodynamics Aircraft/Project: F-15 |
| ID Code: | 601 |
| Deposited On: | 06 Febuary 2006 |
| Additional Information: | 143 pages. |
