New Analysis Scheme of Flow-Acoustic Coupling for Gas Ultrasonic Flowmeter with Vortex near the Transducer

Abstract

Ultrasonic flowmeters with a small or medium diameter are widely used in process industries. The flow field disturbance on acoustic propagation caused by a vortex near the transducer inside the sensor as well as the mechanism and details of flow-acoustic interaction are needed to strengthen research. For that reason, a new hybrid scheme is proposed; the theories of computational fluid dynamics (CFD), wave acoustics, and ray acoustics are used comprehensively by a new step-by-step method. The flow field with a vortex near the transducer, and its influence on sound propagation, receiving, and flowmeter performance are analyzed in depth. It was found that, firstly, the velocity and vortex intensity distribution were asymmetric on the sensor cross-section and acoustic path. Secondly, when passing through the vortex zone, the central ray trajectory was deflected significantly. The sound pressure on the central line of the sound path also changed. Thirdly, the pressure deviation becomes larger with as the flow velocity increases. The deviation was up to 17% for different velocity profiles in a range of 0.6 m/s to 53 m/s. Lastly, in comparison to the theoretical value, the relative deviation of the instrument coefficient for the velocity profile with a vortex near the transducer reached up to −17%. In addition, the rationality of the simulation was proved by experiments.

Bias error in measurement of complex flow regime with ultrasonic flowmeter

“…After obtaining the transit time of the ultrasonic wave propagating in the co-current and countercurrent between the transducers, one can solve the flow velocity of the flow field according to equation (1), such that,…”

“…Flow measurement is important to industrial and agricultural production as well as people's daily life [1] . Thus, it attracts the attention of a vast spectrum of scholars and engineers [2] .…”

Optimize the Rectifier Structure to Improve the Accuracy of Gas Ultrasonic Flowmeter Under Low Flow Conditions

“…The optimization of channel structure and algorithm is generally applied to the pipeline structure under specific conditions, which has some limitations. It is an effective method to improve the detection accuracy of a flowmeter by designing a rectifier to stabilize irregular flow fields and reduce the eddy current 9 .…”

Research and application of ultrasonic gas flow meter performance on-line audit

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