INVESTIGATION OF THE VARIATION WITH REYNOLDS NUMBER OF THE BASE, WAVE, AND SKIN-FRICTION DRAG OF A PARABOLIC BODY OF REVOLUTION (NACA KM-10) AT MACH NUMBERS OF 1.62, 1.93, AND 2.41 IN THE LANGLEY 9-INCH SUPERSONIC TUNNEL

摘要

An investigation has been made at Mach numbers of 1.62, 1.93, and 2.41 to determine the effect of varying Reynolds number upon the base, wave, and skin-friction drag of a parabolic body of revolution (NACA RM-10, no fins) for conditions of zero heat transfer. The tests covered a Reynolds number range of approximately 1 X 106 to 11 X 106 for both fixed and natural transition at each Mach number.nThe results show that for laminar flow over the entire body there is a gradual increase in forebody pressure drag with increasing Reynolds number in the lower Reynolds number range;when the Reynolds number for transition is approached and exceeded, the variation is small. In gen¬eral, the theories considered gave fair predictions of the forebody pres¬sure drag. Boundary-layer transition appears to be very sensitive to surface conditions at the lowest Mach number only and flow irregularities have significant effects upon transition on the body surface and within the wake. For estimations of the skin-friction drag the Frankl-Voishel extended theory is satisfactory for the turbulent case and the incom-pressible Blasius theory for the laminar case;in the transition region the experimental rise was more abrupt than that predicted by any of the methods considered. Laminar-boundary-layer profiles were in good agree-ment with the Von Karman-Tsien profiles, and the transitional and tur¬bulent profiles were in fair agreement with power-law profiles. Values of skin-friction drag obtained from the boundary-layer surveys were in reasonable agreement with the experimental values obtained from force and pressure measurements.