Flow Measurement Techniques, Calibration

Abstract

This chapter is about the flow measurement techniques and the calibration of the probes that are used for measuring different flow conditions. It starts with the measurement instruments for high frequency data acquisition. For measuring the time dependent high frequency flow field, hot wire anemometry (HWA) is introduced. The corresponding probe types, such as hot wire and hot film and their arrangements are discussed. Furthermore, the physical principles as well as the governing equations of HWA is extensively discussed. Measuring the time averaged flow quantities such as pressure, temperature and velocity is achieved by using simple probes. As an example, using a five hole probe, a three-dimensional velocity field can be measured accurately. This requires the design and manufacturing of a calibration facility, its instrumentation and data acquisition system. Once the facility is established, the five hole probe can be calibrated. This chapter also shows the calibration procedure along with the final data.