Miralles Sophie, Verhille Gautier, Plihon Nicolas, Pinton Jean-François
Laboratoire de Physique, École Normale Supérieure de Lyon, CNRS UMR 5672 & Université de Lyon, F-69364 Lyon, France.
Rev Sci Instrum. 2011 Sep;82(9):095112. doi: 10.1063/1.3630949.
A new type of velocimeter, capable of local velocity measurements in conducting fluids, is introduced. The principle of the "magnetic-distortion probe" is based on the measurement of the induced magnetic field by the flow of a conducting fluid in the vicinity of a localized magnetic field. The new velocimeter has no moving parts, and can be enclosed in a sealed cap, easing the implementation in harsh environments, such as liquid metals. The proposed method allows one to probe both the continuous part and fluctuations of the velocity, the temporal and spatial resolution being linked to the actual geometric configuration of the probe. A prototype probe has been tested in a gallinstan pipe flow and in a fully turbulent flow of liquid gallium generated by the counter rotation of two coaxial impellers in a cylinder. The signals have been compared to a reference potential probe and show very good agreement both for time-averaged velocities and turbulent fluctuations. The prototype is shown to detect motion from a few cm s(-1) to a few m s(-1). Moreover, the use of the magnetic-distortion probe with large-scale applied magnetic field is discussed.
介绍了一种新型测速仪，它能够对导电流体中的局部速度进行测量。“磁畸变探头”的原理基于对导电流体在局部磁场附近流动时感应磁场的测量。这种新型测速仪没有活动部件，可以封装在密封帽中，便于在诸如液态金属等恶劣环境中使用。所提出的方法能够探测速度的连续部分和波动，时间和空间分辨率与探头的实际几何结构相关。一个原型探头已在镓铟锡合金管道流以及由圆柱体内两个同轴叶轮反向旋转产生的液态镓充分湍流中进行了测试。已将信号与参考电位探头进行比较，结果表明在时间平均速度和湍流波动方面都具有很好的一致性。该原型能够检测到几厘米每秒到几米每秒的运动。此外，还讨论了在大规模外加磁场情况下磁畸变探头的应用。
