Use of magnetic resonance imaging to visualize impregnation across aligned cylinders due to capillary forces

Abstract

Transverse flow across micro-cylinders has been previously approached via both analytical and experimental techniques, but there is still a need for a reliable experimental method to expose the minutiae of the capillary flow front advancement. The present paper illustrates the potential of magnetic resonance imaging (MRI) to track the movement of the fluid across cylindrical samples made of aligned micro-cylinders due to capillary action. The results underline the capabilities of MRI to visualize the flow front advancement through the fibrous porous samples, and provide an enhanced understanding of the way spontaneous capillary impregnations of such samples develop, with the compression of entrapped air in the samples that opposes the flow. The results shed light on the role of entrapped air, the porosity and the variation in the flow behavior along with the limitations of MRI, as perceived in our study.