Accession Number:

AD0263080

Title:

HEAT TRANSFER AND BOUNDARY-LAYER TRANSITION ON A HIGHLY POLISHED HEMISPHERE-CONE IN FREE FLIGHT AT MACH NUMBERS UP TO 3.14 AND REYNOLDS NUMBERS UP TO 24 X 106

Descriptive Note:

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON D C

Personal Author(s):

Report Date:

1961-09-01

Pagination or Media Count:

1.0

Abstract:

A highly polished hemisphere-cone having a ratio of nose radius to base radius of 0.74 and a halfangle of 14.5 degrees was flight tested at Mach numbers p to 4.70. Temperature and pressure data were obtained at Mach numbers up to 3.14 and a free-stream Reynolds number of 24 x 10 to the 6th power based measured an interferometer. The measured Stanton numbers were in good agreement with theory. Transition Reynolds numbers based on the laminar boundary-layer momentum thickness at transition ranged from 2,190 to 794. Comparison with results from previous tests of blunt shapes having a surface roughness of 20 to 40 microinches showed that the high degree of polish was instrumental in delaying the transiton body diameter. The nose of the model had a surface roughness of 2 to 5 microinches as measured an interferometer. The measured Stanton numbers were in good agreement with theory. Transition Reynolds numbers based on the laminar boundary-layer momentum thickness at transition ranged from 2,190 to 794. Comparison with results from previous tests of blunt shapes having a surface roughness of 20 to 40 microinches showed that the high degree of polish was instrumental in delaying the transition from laminar to turbulent flow. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE