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Publication Citation: The Effect of Turbulence on a Multi-Hole Pitot Calibration

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Author(s): Christopher J. Crowley; Iosif I. Shinder; Michael R. Moldover;
Title: The Effect of Turbulence on a Multi-Hole Pitot Calibration
Published: June 10, 2013
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
Pages: pp. 106 - 109
Keywords: airspeed calibration, multi hole Pitot tube, detached boundary layer, and Turbulence.
Research Areas: Flow, Calibrations, Calibrations (Mechanical), Fluids, Metrology