Underwater measurements of flowability by angle of repose, Hausner ratio and Jenike shear cell

Abstract

Flowability is important for characterizing particulate materials. Some simple measurements, such as the Hausner ratio and angle of repose, are used to compare materials, and more sophisticated devices, such as the Jenike shear cell and ring shear tester, are used for design purposes. However, these devices are only used for measurements in air; thus, underwater operations lack such measurements and design models based on flowability measurements. This work shows that flowability can be measured underwater by simple modifications to the apparatuses. Although underwater flowability was found to be much smaller than that in air owing to negligible cohesive forces, such an approach enables the adoption of models developed for systems in air for underwater system design. In addition, more in-depth research on particulate material structure and flow by eliminating van der Waals forces can be conducted.