Multipath Flow Metering of High-Velocity Gas Using Ultrasonic Phased-Arrays

Christoph Haugwitz,Jan Hinrichs,Peter F Pelz,Claas Hartmann,Johannes Brotz,Mario Kupnik,Matthias Rutsch,Gianni Allevato,Dieter Bothe

doi:10.1109/ojuffc.2022.3141333

Abstract

In this work we combine a multipath ultrasonic gas flow meter (UFM) with an ultrasonic air-coupled phased-array. This allows complementing the advantages of a multipath UFM, i.e. higher accuracy and more robustness to irregular flow, with the extended velocity measuring range due to sound drift compensation via a phased-array. We created a 3D-printed flow meter consisting of an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$8 \times 8\,\,\lambda /2$ </tex-math></inline-formula> phased-array for transmission and 14 individual receivers for seven upstream and seven downstream sound paths. Measurements were conducted in a test rig with a maximum gas flow rates of 8.3 m 3 s −1 (107 ms −1 ). A differential pressure nozzle was used as reference sensor. Three configurations were compared: Parallel sound paths with a single transmitter; parallel sound paths with the phased-array as transmitter; and fan-shaped sound paths with the phased-array as transmitter. The signal-to-noise ratio (SNR) and deviation of measured flow were used as comparison criteria. In addition, we measured the optimum steering angles of the phased-array required to compensate the sound drift effect. Using the phased-array with the sound drift effect compensation enabled and disabled, the SNR increases by 10.6 dB and 4.95 dB, respectively, compared to the single transmitter setup at 83 m s −1 . Furthermore, the phased-array with compensation active, extends the velocity measuring range by 29%, from 83 ms −1 to 107 m s −1 , while maintaining a similar standard deviation of the flow measured. Besides demonstrating that a phased-array in a gas flow meter significantly extends the measurement range, our setup qualifies as versatile research platform for designing future high-velocity gas flow meters.

Highlights

IntroductionUsing the transit time method, the average flow velocity across a sound path vav is calculated using the upstream tup and downstream tdown propagation times, the path length L, measured from the receiver to the transmitter, and its inclination angle α [Fig. 1(a)], [3], [4], i.e
U LTRASONIC flow meters (UFMs) are widely used in industrial applications [1]
We examine whether and to what extent using a phased-array in a gas flow measurement setup will extend the measuring range by increasing the signal-to-noise ratio (SNR) via sound drift effect compensation with the addition of multipath support, based on our previous work [32]

Summary

Introduction

Using the transit time method, the average flow velocity across a sound path vav is calculated using the upstream tup and downstream tdown propagation times, the path length L, measured from the receiver to the transmitter, and its inclination angle α [Fig. 1(a)], [3], [4], i.e. There is a significant difference between the calculated average flow velocity across a sound path vav and the desired flow velocity averaged over the pipe area varea, due to the lower flow velocities near the walls. In order to obtain the desired velocity varea in a single path UFM, an in-line calibration is required to provide the meter factor k [1]. In contrast to a single path UFM, multipath UFMs measure the flow at different sound path locations and do not require an in-line calibration. While different multipath arrangements are possible, e.g. fan-shaped [6], isosceles triangular [7], orthogonal or star shaped arrangement [8], the parallel arrangement of the paths [Fig. 2(a)] is most commonly used [8]

Methods

Results

Conclusion