基于超声波多普勒法的流通截面分区流速测量的研究

Zonal fluid velocity distribution measurement using Doppler ultrasonic method

传统的超声波多普勒流量计测量的结果是大面积区域内具有统计意义的平均流速，不能反映流速在流通截面上的分布，当雷诺数变化很大时，测量误差很大。基于超声波多普勒效应，本文首次提出了通过对测量信息窗区域的控制，来实现在管流内部进行流速分区测量，进而测量出流速在流通截面上的分布。研制出发射传感器和接收传感器，分别能够产生细长的发射声束和接收声束，使得信息窗区域面积得以控制在很小的范围内，约 ２．１× ４．８ ｍｍ２，位置也被控制在设计值处，满足分区测量要求；在自行设计的模拟管道流动装置中，成功地进行了控制信息窗区域面积和位置的实验，测量值与设计值吻合很好。实现了管道流通截面上的流速分区测量。

The way of the flow measurement by the traditional Doppler ultrasonic flowmeter is detecting the statistic- average value of the flow velocity, which could not reflect the distribution of the flow velocity The greater tke Reynolds number changes, the larger the measurement error is. In order to measure zonal fluid velocity, using the Doppler ultrasonic method to controll the area of info window is presented. In this paper, for one hand, a set of ultrasonic emitter has been developed to slenderize the beam of acoustic wave, and also a set of receiver has been developed to select the back scattered acoustic wave according to the position of the scattering particle, so that, the info window has been controlled within a narrow area; A equipment which can simulate flow has been developed, so as to simulate the flow velocity of a small area of the total section. Covering the small measurement area with info-window, zonal fluid velocity is measured.