Experimental Study on Flow Rate Measurement by Using Cross-Correlation of Temperature Fluctuations

The applicability of cross-correlation method based on fluid temperature fluctuations to flow rate measurement under steady flow condition is investigated with experiments by using an on-line, digital instrument developed by the authors. The thermocouple transducer design, the signal data pre-processing system and the correlator design with chip microprocessor 8031 are described. The experimental results show that the intrinsic temperature fluctuations existing naturally in flowing fluid are adequate to be detected. The method is proved to be a reliable and accurate one of flow rate measurement in turbulent flow. In laminar flow, the measurement is not so satisfactory.