2D ultra-fast MRI of granular dispersion by a liquid jet

Yunan Peng,Eric Hughes,Lynn F Gladden,Marco Ramaioli,Andrew J Sederman,Mick D Mantle,F Radjai,S Luding,S Nezamabadi,J.Y Delenne

doi:10.1051/epjconf/201714009015

Abstract

This paper illustrates the application of ultra-fast magnetic resonance imaging (MRI) as a noninvasive tool to study the dispersion of a dry, static granular bed by the injection of a liquid. Spatial distributions of undispersed grains (poppy seeds) and injected water were independently imaged at sub-millimetre resolution in 2D with ultra-fast MRI techniques. A liquid jet was observed above the bottom injection orifice, complementing optical imaging. Co-registration of the grains and water images enables the interaction of the static grains and of the liquid jet to be observed for the first time in situ . This visualization of the dispersion process can be used to identify optimal process parameters for a fast and uniform dispersion and to validate quantitatively numerical granular-fluid simulations [1].

Highlights

Whereas the steady fluidization of grains by a fluid has been studied extensively, the transient dispersion of grains initially packed in a heap is not well understood
This paper describes how 2D magnetic resonance imaging (MRI) is used to achieve a better understanding of liquid jetting in granular dispersion
This paper reports the first use of MRI to study a three-phase dispersion system

Summary

Introduction

Whereas the steady fluidization of grains by a fluid has been studied extensively, the transient dispersion of grains initially packed in a heap is not well understood. When a liquid jet is injected upwards into a dry static bed of poppy seeds its decompaction and progressive destruction can be monitored in time using twodimensional magnetic resonance imaging techniques. Two MRI protocols were used to observe the water and grains within the dispersion cell: (i) 2D velocity compensated Fast Low Angle Shot (vc-FLASH) [8,9], which highlights the liquid only; (ii) 2D standard Rapid Acquisition with Relaxation Enhancement (RARE) [10,11], used to image changes to static poppy seeds.

Results

Conclusion