Dr Stefanos Papanicolopulos

Project Title: Tracking granular flows using multiple instrumented grains

Granular materials are found widely in nature (for example sand and other soils) and in industry (for example corn, sugar, detergents, pharmaceutical tablets, pellets). The mechanics of granular processes are therefore of major importance across many different applications, scientific disciplines and industries, for example failure of soils and landslides (geotechnical engineering), design of silos (structural/process engineering), tabletting (pharmaceutical engineering), soil erosion (coastal/agricultural engineering), and degradation of railway ballast (railway engineering). All these applications require understanding, simulation and prediction of granular flows. This is difficult, due to the complex solid-, liquid and gas-like behaviour of these materials. We therefore need robust, accurate, cheap methods for tracking granular flows, easily deployable in the lab and in situ.

This project is an initial study, leading to an extensive project to develop an industrially applicable technology for tracking granular flows using multiple instrumented grains (IGs). Based on a previous IG design used for hydraulics experiments, we have developed a new customised design improving on size and robustness. A separate IG design, based on commercial off-the-shelf electronics, was also developed to allow for faster evaluation of alternative electronics components. Single-particle measurements have highlighted the significant difficulties in directly determining position, while also providing results on the usability of measurements of particle rotations. Multiple IGs have been produced, to allow multi-particle measurements.

Preliminary results were presented at the PARTICLES 2019 conference, with further publications currently in preparation. Based on the preliminary results, a larger-scale funding application will be submitted in the coming months, aiming to achieve the vision of the proposed research that is to develop a measurement methodology to track granular flows based on many instrumented grains.