IEEE Trans Ultrason Ferroelectr Freq Control. 2017 Sep;64(9):1327-1335. doi: 10.1109/TUFFC.2017.2693920. Epub 2017 Apr 12.
Controllable magnetic fields can be used to optimize flows in technical and industrial processes involving liquid metals in order to improve quality and yield. However, experimental studies in magnetohydrodynamics often involve complex, turbulent flows and require planar, two-component (2c) velocity measurements through only one acoustical access. We present the phased array ultrasound Doppler velocimeter as a modular research platform for flow mapping in liquid metals. It combines the pulse wave Doppler method with the phased array technique to adaptively focus the ultrasound beam. This makes it possible to resolve smaller flow structures in planar measurements compared with fixed-beam sensors and enables 2c flow mapping with only one acoustical access via the cross beam technique. From simultaneously measured 2-D velocity fields, quantities for turbulence characterization can be derived. The capabilities of this measurement system are demonstrated through measurements in the alloy gallium-indium-tin at room temperature. The 2-D, 2c velocity measurements of a flow in a cubic vessel driven by a rotating magnetic field (RMF) with a spatial resolution of up to 2.2 mm are presented. The measurement results are in good agreement with a semianalytical simulation. As a highlight, two-point correlation functions of the velocity field for different magnitudes of the RMF are presented.
可控磁场可用于优化涉及液态金属的技术和工业过程中的流动，以提高质量和产量。然而，磁流体动力学的实验研究通常涉及复杂的湍流流动，并且需要仅通过一个声学通道进行平面、两分量（2c）速度测量。我们提出了相控阵超声多普勒流速计作为液态金属流动测绘的模块化研究平台。它将脉冲波多普勒方法与相控阵技术相结合，自适应地聚焦超声波束。这使得与固定波束传感器相比，在平面测量中能够分辨更小的流动结构，并通过交叉波束技术仅通过一个声学通道实现 2c 流量测绘。从同时测量的二维速度场中，可以得出用于湍流特征化的量。通过在室温下对合金镓-铟-锡进行的测量，证明了该测量系统的能力。介绍了在由旋转磁场（RMF）驱动的立方容器中的流动的二维、2c 速度测量，空间分辨率高达 2.2 毫米。测量结果与半解析模拟吻合较好。作为亮点，给出了不同 RMF 幅度下速度场的两点相关函数。
