CALIBRATION OF A COMBINED PITOT-STATIC TUBE AND VANE-TYPE FLOW ANGULARITY INDICATOR AT TRANSONIC SPEEDS AND AT LARGE ANGLES OF ATTACK OR YAW

摘要

A wind-tunnel investigation has been made to provide information concerning the characteristics of a combined pitot-static tube and vane-type flow-angularity indicator at large angles of attack or yaw and at speeds near the speed of sound.nThe results indicate that the angles of attack or yaw at which the total-pressure error is 0.01 (after correction of indicated total pressures for losses due to bow wave ahead of tube at Mach numbers greater than 1.00) vary linearly with Mach number and increase from approximately 21.0° at a Mach number of 0.60 to about 24.3° at a Mach number of 1.10. The static-pressure error is affected more by changes in angle of yaw than by corresponding changes in angle of attack and is positive (measured pressure greater than stream pressure) for angles of attack and negative for angles of yaw. The calibration factor for the pitot-static tube varies linearly with Mach number up to a Mach number of approximately 0.99 followed by an abrupt decrease in value at a Mach number near 1.00. The maximum error in measuring flow angularity by means of the vanes is of the order of I.50 and occurs at a Mach number of 1.10 and an angle of attack of 25°.