Flow patterns in an ultrasonic liquid flow meter

Abstract Flow visualisation studies have been undertaken for the case of an in-line, ultrasonic transducer housing in a cylindrical cross-section metering duct by direct observation of injected dye and of particles illuminated by a laser sheet. Results are presented for single and three bluff-body strut attachment of the transducer housing to the duct wall at Reynolds numbers (based on mean velocity and meter duct diameter) of 750, 1900 and 7950. Transducer face and wall fillet recirculation zones were dependent on the number of attachment struts and on the flow rate. The results are discussed in terms of their consequences for the performance of an ultrasonic transit time flow meter.