09-12: A Reynolds Number Correction for Pitot Measurement

The Pitot tube has been the mainstay of flow measurement in cooling towers for decades, but this isn't the only application for velocity probes of this type. Unlike the cooling tower flow, most other applications of these and similar probes consider the Reynolds number-typically at the head of the probe. The correction for Reynolds number in the derived correlations for such probes is iterative, but easily implemented and converges quickly. The information necessary to incorporate a correction for Reynolds number is often collected-but not used-along with the other data when the probe is being calibrated. This paper will explore the efficacy of utilizing a local Reynolds number correction with several Pitot probes and whether or not this actually reduces the overall uncertainty of the final flow measurement.