(236b) MRI Measurement of Particle Velocity Distribution in Hopper Flow

It is generally difficult to measure the particle motion inside of dense granular flows or fluid-particle flows. Recently, MRI (Magnetic Resonance Imaging) attracts attention as a technique to measure the inner structure of such flows. MRI is one of the non-invasive measurement techniques. MRI is harmless to human bodies and can measure the velocity field, which are the outstanding advantage of MRI compared to other measurement techniques such as X-ray tomography or PEPT. In the present paper, an MRI measurement was performed to measure the velocity distribution of discharged particles through a three-dimensional cylindrical hopper. The cylindrical hopper is filled with mono-dispersed spherical particles. The effect of the hopper shape on the flow pattern was studied. The tagging method and the phase method, which are the velocity measurement technique of MRI, are employed to measure the particle velocity distribution. A tapered region near the bottom hole of the hopper is clearly visualized by the tagging method. The experimental results were compared with results of a DEM (Discrete Element Method) calculation.