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

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
Author: James J. Buglia
Publisher:
Total Pages: 0
Release: 1961
Genre:
ISBN:
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A highly polished hemisphere-cone having a ratio of nose radius to base radius of 0.74 and a half-angle of 14.5 was flight tested at Mach numbers up 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 106 based on body diameter. The nose of the model had a surface roughness of 2 to 5 microinches as measured with 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.

Experimental Convective Heat Transfer to a 4-inch and 6-inch Hemisphere at Mach Numbers from 1.62 to 3.04

Experimental Convective Heat Transfer to a 4-inch and 6-inch Hemisphere at Mach Numbers from 1.62 to 3.04
Author: Leo T. Chauvin
Publisher:
Total Pages: 24
Release: 1954
Genre: Aerodynamics
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Abstract: Equilibrium temperatures and heat-transfer coefficients for a hemispherical nose have been measured for Mach numbers from 1.62 to 3.04. Heat transfer to the surface of the hemisphere was presented as Stanton number against Reynolds number for various surface heating conditions. Heat transfer at the stagnation point has been measured and correlated with theory. Transition from a laminar to a turbulent boundary layer was obtained at Reynolds numbers of approximately 1 x 106 corresponding to a region on the body located between 45© and 60© from the stagnation point.

Examination of the Existing Data on the Heat Transfer of Turbulent Boundary Layers at Supersonic Speeds from the Point of View of Reynolds Analogy

Examination of the Existing Data on the Heat Transfer of Turbulent Boundary Layers at Supersonic Speeds from the Point of View of Reynolds Analogy
Author: Alvin Seiff
Publisher:
Total Pages: 654
Release: 1954
Genre: Aerodynamics, Supersonic
ISBN:
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Heat-transfer data from four wind-tunnel experiments and two free-flight experiments with turbulent boundary layers have been examined to see whether or not they are well represented by the Reynolds analogy or a modification thereof. The heat-transfer results are put into the form of dimensionless Stanton numbers based on fluid properties at the outer edge of the boundary layer and are compared with skin-friction coefficients for the same Mach numbers and wall to free-stream temperature ratios as obtained from an interpolation of the existing skin-friction data. The effective Reynolds number is taken to be the length Reynolds number measured from the effective turbulent origin, a position which differs importantly from the leading edge of the test surface in some cases.