Permeability Distribution Reconstruction Method Based on Magnetic Induction Vector

In a gas-liquid–solid three-phase fluidized bed with a magnetic catalyst as the solid phase, the inhomogeneous distribution of the phases leads to the emergence of solid clusters and bubble clusters. These clusters are characterized by permeability that distinguishes them from the gas-liquid–solid mixture background field. Electromagnetic tomography (EMT) based on tunneling magnetoresistance (TMR) reconstructs the permeability distribution within the fluidized bed pipe using boundary measurements to enable the detection of clusters. The current study utilizes the magnetic induction magnitude or the component in the TMR sensitive axis direction as boundary measurements, whereas the magnetic induction direction, which also contains permeability distribution information, has not been effectively used. In order to integrate both the magnitude and direction information of the magnetic induction for improved permeability distribution reconstruction, this article proposes a novel method that reconstructs the permeability distribution using the magnetic induction vector and designs an EMT system based on biaxial TMR (Bi-TMR) to implement this method. Simulation and experimental results demonstrate that reconstructing the permeability distribution using the magnetic induction vector yields higher accuracy compared to using the magnitude or component.