Laboratory of Medical Imaging, Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
Netherlands Organisation for Applied Scientific Research (TNO), Oude Waalsdorperweg 63, 2597 AK The Hague, The Netherlands.
Sensors (Basel). 2022 Jul 6;22(14):5068. doi: 10.3390/s22145068.
Clamp-on ultrasonic flow meters (UFMs) are installed on the outside of the pipe wall. Typically, they consist of two single-element transducers mounted on angled wedges, which are acoustically coupled to the pipe wall. Before flow metering, the transducers are placed at the correct axial position by manually moving one transducer along the pipe wall until the maximum amplitude of the relevant acoustic pulse is obtained. This process is time-consuming and operator-dependent. Next to this, at least five parameters of the pipe and the liquid need to be provided manually to compute the flow speed. In this work, a method is proposed to obtain the five parameters of the pipe and the liquid required to compute the flow speed. The method consists of obtaining the optimal angles for different wave travel paths by varying the steering angle of the emitted acoustic beam systematically. Based on these optimal angles, a system of equations is built and solved to extract the desired parameters. The proposed method was tested experimentally with a custom-made clamp-on UFM consisting of two linear arrays placed on a water-filled stainless steel pipe. The obtained parameters of the pipe and the liquid correspond very well with the expected (nominal) values. Furthermore, the performed experiment also demonstrates that a clamp-on UFM based on transducer arrays can achieve self-alignment without the need to manually move the transducers.
夹装式超声流量计 (UFMs) 安装在管壁外侧。通常，它们由两个安装在斜楔上的单元素换能器组成，通过斜楔与管壁实现声学耦合。在流量测量之前，通过手动沿管壁移动一个换能器，直到获得相关声脉冲的最大幅度，来将换能器放置在正确的轴向位置。这个过程既耗时又依赖于操作人员。此外，至少需要手动提供五个管道和液体参数来计算流速。在这项工作中，提出了一种方法来获取计算流速所需的五个管道和液体参数。该方法通过系统地改变发射声束的转向角来获得不同波传播路径的最佳角度。基于这些最佳角度，建立并求解一个方程组以提取所需的参数。该方法已通过由两个线性阵列放置在充满水的不锈钢管上的定制夹装式 UFM 进行了实验测试。所获得的管道和液体参数与预期（标称）值非常吻合。此外，所进行的实验还表明，基于换能器阵列的夹装式 UFM 可以实现自动对准，而无需手动移动换能器。
