Liquid Flow Measurement by Cross-Correlation of Temperature Fluctuations

Abstract

The applicability of the temperature cross-correlation method to the measurement of liquid flow under steady and pulsating flow conditions is investigated and some further results to those published earlier are presented. The method is proved to be an accurate and reliable method of flow measurement in laminar flow of highly viscous liquids and turbulent flow of liquids under steady and pulsating flow conditions. In laminar flow, the measurement is dependent on the velocity profiles and hence sensitive to any disturbances which may distort the velocity profiles. In pulsating flow, the measurement is dependent on a parameter called the ‘Frequency parameter’ (KR). Only if KR <1 can the flow meter, calibrated for steady flow measurement, meter pulsating flow accurately. This condition is easily satisfied by highly viscous liquids. The measurement technique provides a linear output and an accuracy better than 3% can be achieved.