Ultrasonic measurement of gas flow using electrostatic transducers
Ultrasonic measurement of gas flow using electrostatic transducers
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DOI：
10.1016/s0041-624x(02)00259-7
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发表时间：
2002-05-01
期刊：
影响因子：
4.2
通讯作者：
Wright, WMD
中科院分区：
文献类型：
--
作者：
O'Sullivan, IJ;Wright, WMD
超声波气体流量计通常使用窄带压电式换能器装置来检测管道中的气体流动。在这项工作中，研究了工作频率高达1 MHz的宽带静电换能器对气体流量超声测量的适用性。采用了超声波气体流量测量的渡越时间法，并在可产生17.5m/S气体流量范围的实验室试验台上进行了实验，该试验台还允许不同原型流量段的互换。使用单独的发送/接收静电换能器布置来测量询问气流的超声波的飞行时间。考虑了两种流量计结构。第一个人在451处询问了上游和下游反向传播的流动。第二次询问包括在气流45度处的上游询问和垂直于流动方向的询问。利用超声实验数据和风速计测量数据，计算了沿超声路径的流体速度与管内平均流体速度之间的K因子。使用计算流体力学软件包FLOTRAN(C)(Ansys Inc.)对所有换能器配置进行数值建模。随后将两种换能器布置的理论气体流速与实验值进行了比较，发现两者非常吻合。与通过时间测量(C)2002 Elsevier Science B.V.同时，还观察到接收到的超声波信号的随流量变化的频率偏移。版权所有。
Ultrasonic gas flowmeters typically use narrowband piezoelectric transducer arrangements for interrogating the flow of gas in a pipe. In this work, the suitability of broadband electrostatic transducers operating at frequencies of up to 1 MHz for ultrasonic measurement of gas flow has been investigated. The transit time method of ultrasonic gas flow measurement was adopted and experiments were carried out using a laboratory test rig capable of producing a range of gas flowrates up to 17.5 m/s. The test rig also allowed easy interchange of different prototype flowmetering sections. Times of flight of ultrasonic waves interrogating the gas flow were measured using separate send/receive electrostatic transducer arrangements. Two flowmeter configurations were considered. The first interrogated the flow at 451 in contra-propagating upstream and downstream directions. The second consisted of an upstream interrogation at 45degrees to the gas flow and an interrogation made normal to the flow direction. k factors correlating the fluid velocity along the ultrasonic path with the mean fluid velocity in the pipe were calculated using experimental ultrasonic data and anemometer measurements. All transducer configurations were numerically modelled using the computational fluid dynamics software package FLOTRAN(C) (ANSYS Inc.). Theoretical gas flow velocities for both transducer arrangements were subsequently compared with experimental values and found to be in excellent agreement. A flow-dependent frequency shift of the received ultrasonic signals was also observed simultaneously with the transit time measurement, (C) 2002 Elsevier Science B.V. All rights reserved.