Gravity-driven granular flows in pipes : teaching experimental skills in the context of granular flows

Granular flows appear frequently in the natural world and in civil engineering applications. These flows can exhibit features which are surprising and counter-intuitive and are often used to test the limits of the classical continuum approximation for modelling of fluid flows. An important sub-class of the granular flows are the gravity-driven granular flows, which include the granular column collapse and the flow of granular material down through a vertical pipe. In this article, quantitative analysis is performed of the flow using video analysis software. The utility and relevance of the experiment for development of experimental skills in physics students and modelling of unexpected phenomena is discussed