The Effect of Turbulence on a Multi-Hole Pitot Calibration

Published: June 10, 2013

Author(s)

Christopher J. Crowley, Iosif I. Shinder, Michael R. Moldover

Abstract

Abstract- Accurate calibrations of multi-hole Pitot tubes require thousands of measurements spanning ranges of the fluid’s velocity, and the pitch and yaw angles. When calibrating a commercially-manufactured multi-hole Pitot tube in NIST’s low-turbulence wind tunnel, we found hysteresis in certain ranges of airspeed, pitch angle, and yaw angle. In the worst case, the hysteresis caused a calibration error of 30 %. We demonstrate that the hysteresis was caused by a flow instability associated with flow separation. A turbulence intensity of only 1 % removes the hysteresis; however, the calibration dependends on the turbulence intensity over the entire range of our measurements (0.25 % to 2 %). Therefore, multi-hole Pitot tubes should be calibrated and used at the same turbulence levels.
Citation: Flow Measurement and Instrumentation
Volume: 33
Pub Type: Journals

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Keywords

airspeed calibration, multi hole Pitot tube, detached boundary layer, and Turbulence.
Created June 10, 2013, Updated February 19, 2017