Boundary-Layer Development and Skin Friction at Mach Number 3.05

Boundary-layer studies consisting of schlieren observations and momentum surveys were made on hollow cylinder models with their axes alined parallel to the stream. Results were obtained for three model diameters and for natural and artificially induced turbulent boundary-layer flows. Transition Reynolds numbers were found to decrease with decreases in leading-edge thickness and with reductions in tunnel pressure level. Turbulent temperature-recovery factors generally decreased with increasing Reynolds number and were a maximum for the smallest transition Reynolds numbers. The results of this investigation appeared to be consistent with the theoretical turbulent friction formulas of Wilson and with the extended Franki-Voishel analysis of Rubesin, Maydew, and Varga. Velocity profiles in the outer portion of the boundary layer could be approximated reasonably with a 1/7 power profile and were found to be approximately similar in this region. Velocity profiles given by the Karman universal turbulent boundary-layer profile parameters were found to be similar in the laminar sublayer and in the turbulent region.