GOALI: Examination of Gas-Solid Multiphase Flow Dynamics Using Electrical Impedance Tomography

摘要当前需要更好地理解那些由气固混合物流动主导的工业过程，这一提议的动机。由于固体探针会干扰感兴趣的现象（例如，团簇的形成或破坏），因此对这些不稳定的三维流动的特性测量排除了它们的采样。然而，在使用遥感断层扫描方面已经取得了一些成功：在这种技术中，许多光束与流动容器内物质的累积干涉可以用数学方法重建为局部特性的三维时间分辨图。PI提出了“电阻抗断层扫描”，在感兴趣的体积周围安装许多电极，并向它们施加规定的电流。这样就可以从输出电压推断出体积内部阻抗的空间分布。用经典电磁理论可以从这些数据中提取出相分布图（液气、固气）。具体来说，PI建议开发和测试一种固体-气体层析成像技术，该技术将实现空间和时间分辨率。48个电极覆盖的场将是强三维的（1128个独立的投影），分辨率将通过使用多频率激励来提高，其中12个锁定放大器将在相同的时间间隔内收集一个数量级的数据。目标是“在10毫秒内收集完整的数据集”。通过这种方式，PI相信他将能够“检查团簇形成和体积流动动力学以及近壁颗粒动力学”。

AbstractThe proposal is motivated by the current need to better understand those industrial processes dominated by the flow of gas-solid mixtures .The attendant property measurement of these unsteady, three-dimensional flows precludes their sampling, since solid probes would disturb the phenomena of interest (the formation or destruction of clusters, for instance). There has been some success, however, in using remote sensing tomography: in such a technique, the cumulative interference of many beams with the matter inside a flow container, can be reconstructed mathematically into a three-dimensional time-resolved map of local properties. The PI proposes the "electrical impedance tomography", in which a number of electrodes are mounted around the volume of interest, and a prescribed current is applied to them. It is then possible to infer from the exiting voltages the spatial distribution of impedance inside the volume. The phase distribution map (liquid-gas, solid-gas) can be extracted from this data by classical electromagnetic theory. Specifically, the PI proposes to develop and test a solid-gas tomographic technique, where both space and time resolution will be achieved. The field covered by 48 electrodes will be strongly three dimensional (1128 independent projections), and the resolution will be boosted by using multiple frequency excitation, where 12 lock-in amplifiers will collect an order of magnitude more data in the same time interval. The goal is "to collect a complete data set within 10 milliseconds". In this fashion, the PI is confident that he will be able to " examine cluster formation and bulk flow dynamics, and near wall particle dynamics".