Determination of Transition Reynolds Number in the Transonic Mach Number Range
Final technical rept. Dec 1969-Jun 1970
ARO INC ARNOLD AFS TN
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The report presents the results of an investigation to determine the transition Reynolds number characteristics of the Propulsion Wind Tunnel 16T and the Aerodynamic Wind Tunnel 4T by measuring the location of boundary-layer transition on a 10-deg total-angle cone. Boundary-layer thickness on the test section walls and test section noise levels were measured in an attempt to determine their influence on boundary-layer transition location. Transition Reynolds number decreased with increasing Mach number in both tunnels with a higher rate of change in Tunnel 4T. Transition Reynolds number decreased with increasing unit Reynolds number for free-stream Mach numbers or 1.0 and alternated between decreasing and increasing with increasing unit Reynolds number for free-stream Mach numbers 1.0. Test results indicated that boundary- layer transition on the cone surface was affected by test section wall angle, wall porosity, and the noise radiating from the test section walls. The boundary-layer acoustic level, as measured on the cone surface, was relatively unaffected by transition location for subsonic Mach numbers.
- Test Facilities, Equipment and Methods
- Fluid Mechanics