Temperature recovery factors were determined on the cylindrical surface of a number of 40 deg cone cylinder models at zero angle of attack and at M = 2.86. The investigation was performed in a 40- by 40-cm intermittent tunnel and an 18- by 18-cm continous tunnel. With atmospheric tunnel-supply conditions, the turbulent recovery factor was found to be 0.89 + or - 0.5% and independent of Reynolds number in the range of 200,000 to 800,000, with Reynolds number based on wall conditions. The turbulent recovery factor can be represented by the cube root of the Prandtl number for a Prandtl number calculated at wall conditions. In the transitional region of the boundary layer, a maximum recovery factor 0.5 to 1% higher than the turbulent value was obtained. Boundary layer history had a marked effect on the value of the recovery factor. The results were compared with the theoretical and experimental findings of other investigators.

Abstract: Temperature recovery factors were determined for a slender, thin-walled cone-cylinder, having a 12° vertex angle and a 1.25-inch-diameter cylinder, at Mach numbers from 3.02 to 6.30. The angle-of-attack range was 0° to 45° at Mach numbers up to 3.50, and about 0° to 20° at Mach numbers from 4.23 to 6.30. A transverse cylinder of the same diameter was also tested at Mach number 3.02. Free-stream Reynolds numbers varied from 1.8 to 11.0 million per foot. Flow visualization studies of boundary-layer transition and flow separation were made and the results correlated with recovery-factor measurements.

The report describes an experimental study of compressible turbulent boundary layers for which the upstream history was systematically varied. A series of experiments was conducted using both a supersonic half nozzle and a conventional flat plate for which the nozzle throat and flat plate leading edge can be temperature controlled. The supersonic nozzle provided a favorable upstream pressure gradient together with a controlled thermal history at the throat. The flat plate provided upstream temperature control with no pressure history. Velocity and temperature profile and heat-transfer measurements were made in a downstream region of zero-pressure-gradient and constant wall temperature. (Modified author abstract).

A turbulent-boundary-layer temperature recovery factor f 0.885 plus or minus 0.011 was measured on both a 10 degree cone and a 40 degree cone cylinder at Mach numbers from 2 to 3.8 and Reynolds numbers based on surface kinematic viscosity from 400,000 to 4,000,000. Comparisons are made with available theories and experiments.