Wind-Tunnel Investigation of a Number of Total-Pressure Tubes at High Angles of Attack Subsonic Speeds

摘要

The National Advisory Committee for Aeronautics is investigating the possibility of designing a fixed total-pressure tube which will remain insensitive to inclination of the air stream over a wide range of angle of attack throughout the subsonic and supersonic speed ranges. As the first step in this program the variation of total-pressure error with angle of attack of 39 total-pressure tubes has been determined for an angle-of-attack range of + or - 45 deg and an indicated airspeed of 195 miles per hour. The design of these tubes was varied in such a manner that the effects of external shape, internal shape, and configuration of the total- pressure entry could be determined. The external shapes tested included cylindrical-, conical-, and ogival-nose sections. The internal shapes and total-pressure entries were varied on the basis of such factors as size of impact opening, shape of internal chamber, internal bevel, leading-edge sharpness, slant profile, and shielding (combined with venting).