Orientation of Orifices on Bodies of Revolution for Determination of Stream Static Pressure at Supersonic Speeds

摘要

Experimental data obtained in the Langley 4- by 4-foot supersonic tunnel for a parabolic body of revolution of large fineness ratio at a Mach number of 1.59 and a Reynolds number of 3.6 x 10(exp 6) have been analyzed to locate positions at which static-pressure orifices will indicate a constant static pressure (stream static or otherwise) independent of the pitch-yaw attitude of the body. The results show that by locating two orifices at symmetrical radial positions with respect to the angle-of-attack plane and by using a single pressure given by the average of the two orifice readings, appreciable pitch-yaw ranges can be obtained while a constant static pressure is maintained. The proper radial positions of the orifices vary with the axial location. At the front of the body tested, the proper radial positions are +/- 67 deg. measured from the bottom of the body; at 1/3 of the body length, the locations are +/- 52 deg.; and at the maximum diameter, the locations are +/- 37.5 deg. For this Mach number and at these stations, the maximum angles of attack obtainable within a static-pressure error of 1.75 percent were 10 deg, 20 deg., and 16 deg., respectively. These angle-of-attack limits were unchanged by yaw provided the yaw angles were less than +/- 5 deg., +/- 8 deg., and +/- 5 deg., respectively.