Design, simulation, fabrication and testing of ultrasonic gas flowmeter transducer (sensor)

Abstract

Purpose Invasive transit-time ultrasonic flow measurement involves the use of ultrasonic transducers, which sense the flowing fluid and are the most important parts of an ultrasonic flowmeter. In this study, two ultrasonic transducers were designed, numerically simulated and fabricated to be used in an ultrasonic gas flowmeter. Design/methodology/approach PZT-5H piezoceramic elements with specific dimensions were designed and used as beating heart inside the transducers. Different methods, including impedance-frequency analysis, optical emission spectroscopy and performance tests in pressurized chambers were used to evaluate the piezoelectric elements, ultrasonic transducer housings and the fabricated transducers, respectively. In addition, finite element method results showed its ability for design stages of ultrasonic transducer. Findings Experimental results for transit time difference (TTD) and the normalized received voltage were compared with simulation results at the same conditions. There was a quite good agreement between the two method results. Extensive simulation results showed that under the considered range of environmental conditions, the change of acoustic path length has the most impact on TTD, with respect to temperature and pressure. A change of 1 mm in acoustic path length leads to 0.74 per cent change in TTD, approximately. In addition, for normalized received voltage, 1 bar change in pressure has the most impact and its value is as high as 3.76 per cent. Practical implications This method is possibly used in ultrasonic gas flowmeter fabrication. Originality/value In this work, design, fabrication, experimental tests and numerical simulation of ultrasonic transducers are presented.

Design and applications of MEMS flow sensors: A review

“…Through this article, we only focused on three common types of MEMS flow sensors principles namely thermal, piezoeresistive and piezoelectric devices. There are however few reports on the other types of MEMS flow sensors such as capacitive [196][197][198], ultrasonic [199,200], coriolis flow meter [201][202][203], and turbine [23,204]. Fig.…”

A fully printed sensor with optical readout for real-time flow monitoring

“…This requires somewhat complex readout circuitry, and in combination with the appropriate driving electronics, adds a non-negligible engineering overhead. Additional approaches for flow sensors include flow sensing with ultrasonic transducers, which utilize Doppler or transit time principles of operation [18], and pressure sensors for flow detection, where different approaches such as piezoelectric, piezoresistive [19] or capacitive can be employed. A special case is a differential pressure flow sensor, where flow can be extracted from the difference between the inlet and the outlet of a channel [20].…”

Model-Based Analysis and Regulating Approach of Air-Coupled Transducers with Spurious Resonance

“…It is found feasible to directly read the optimal operating frequency from the impedance or admittance plots when there is no strong coupling between adjacent resonances. However, the impedance of actual transducers somehow exhibits two or more resonant modes at the frequency where a single main resonance is expected [12][13][14][15]. The undesired resonance in the vicinity of a main resonance is called spurious or parasitic resonance.…”