Computer Simulation of Magnetic Resonance Imaging of the Flow of Fluidized Particles

Rapid magnetic resonance imaging (MRI) and velocimetry(MRV) arenon-invasive measurement techniques in 3D opaque systems with & SIM;10ms temporal resolution, enabling new opportunities to challenge theaccuracy of computational models of flow. Comparisons between rapidMRI/MRV and computer simulations are limited by (i) artifacts in rapidMRI techniques and (ii) non-trivial aspects of post-processing ofcomputer simulation data to best match the measurement techniques.Here, we address these issues by starting with data from computerflow simulations of fluidized particles and feeding the data to aphysics-based simulation of MRV measurements, which captures potentialartifacts introduced by the measurement techniques. Flow simulationdata is then post-processed in various ways, demonstrating that (1)velocity and particle position data must be taken from flow simulationsat different points in time to match MRV measurements and (2) imagingmust be faster than flow fluctuation for MRV to produce effectivelyinstantaneous velocity fields.