We have a large multi-disciplinary EPSRC research programme (2017-2021) which has started looking at multiscale two-phase solid-liquid flows in various flow systems (e.g. microchannels, pipes, stirred vessels). The work includes collaboration with the University of Surrey and Daresbury Laboratory, and there is possibility for industrial collaboration. We would like to link a PhD project to this EPSRC programme, thus, the student will benefit from working alongside and interacting with experienced postdoctoral research fellows. There is also possibility for industrial collaboration. The movement of solid-liquid suspensions in pipes and vessels of various scales is a generic complex problem. Industries dependent on solid-liquid flow are numerous including chemicals, consumer goods, food, pharmaceuticals, oil, mining, river engineering, construction, power generation, biotechnology and biomedical. This project will address some of the experimental challenges of the problem using advanced Lagrangian (positron emission particle tracking (PEPT) and Eulerian particle imaging velocimetry (PIV) and micro-PIV) flow imaging techniques to develop the missing physical understanding of the pertinent phenomena of solid-liquid flow in different flow systems across the scales (micro, meso, macro). The work will also address, as appropriate, theoretical aspects of the project in collaboration with the other partners, which may include numerical simulations (e.g. CFD) depending on the candidate's background and interests.