Probing Multiscale Complex Multiphase Flows with Positrons for Engineering and Biomedical Applications

Lead Research Organisation: University of Birmingham
Department Name: Chemical Engineering


A vital challenge for modern engineering is the modelling of the multiscale complex particle-liquid flows at the heart of numerous industrial and physiological processes. Industries dependent on such flows include food, chemicals, consumer goods, pharmaceuticals, oil, mining, river engineering, construction, power generation, biotechnology and medicine. Despite this large range of application areas, industrial practice and processes and clinical practice are neither efficient nor optimal because of a lack of fundamental understanding of the complex, multiscale phenomena involved. Flows may be turbulent or viscous and the carrier fluid may exhibit complex non-Newtonian rheology. Particles have various shapes, sizes, densities, bulk and surface properties. The ability to understand multiscale particle-liquid flows and predict them reliably would offer tremendous economic, scientific and societal benefits to the UK. Our fundamental understanding has so far been restricted by huge practical difficulties in imaging such flows and measuring their local properties. Mixtures of practical interest are often concentrated and opaque so that optical flow visualisation is impossible. We propose to overcome this problem using the technique of positron emission particle tracking (PEPT) which relies on radiation that penetrates opaque materials. We will advance the fundamental physics of multiscale particle-liquid flows in engineering and physiology through an exceptional experimental and theoretical effort, delivering a step change in our ability to image, model, analyse, and predict these flows. We will develop: (i) unique transformative Lagrangian PEPT diagnostic methodology for engineering and physiological flows; and (ii) innovative Lagrangian theories for the analysis of the phenomena uncovered by our measurements.

The University of Birmingham Positron Imaging Centre, where the PEPT technique was invented, is unique in the world in its use of positron-emitting radioactive tracers to study engineering processes. In PEPT, a single radiolabelled particle is used as a flow follower and tracked through positron detection. Thus, each component in a multiphase particle-liquid flow can be labelled and its behaviour observed. Compared with leading optical laser techniques (e.g. LDV, PIV), PEPT has the enormous and unique advantage that it can image opaque fluids, and fluids inside opaque apparatus and the human body. To make the most of this and image fast, complex multiphase and multiscale flows in aqueous systems, improved tracking sensitivity and accuracy, dedicated new radiotracers and simultaneous tracking of multiple tracers must be developed, and new theoretical frameworks must be devised to analyse and interpret the data. By delivering this, we will enable multiscale complex particle-liquid flows to be studied with unprecedented detail and resolution in regimes and configurations hitherto inaccessible to any available technique. The benefits will be far-reaching since the range of applications of PEPT in engineering and medicine is extremely wide.

This multidisciplinary Programme harnesses the synergy between world-leading centres at Birmingham (chemical engineering, physics), Edinburgh (applied maths) and King's College London (PET chemistry, biomedical engineering) to develop unique PEPT diagnostic tools, and to study experimentally and theoretically outstanding multiscale multiphase flow problems which can only be tackled by these tools. The advances of the Programme include: a novel microPEPT device designed to image microscale flows, and a novel medical PEPT validated in small animals for translation to humans. The investigators' combined strengths and the accompanying wide-ranging industrial collaborations, will ensure that this Programme leads to a paradigm-shift in complex multiphase flow research.

Planned Impact

Multiscale complex particle-liquid flows challenge our understanding of multiphase physics. The complex fluid-particle-wall interactions and particle morphological transformations require modelling innovations to improve existing multiphase fluid science and industrial and medical practice. The issues at stake engage academics looking to probe, understand and model these complex multiphase flows, and industrialists seeking to exploit their properties for new applications or enhance existing ones through systematic understanding rather than trial and error. Multiscale particle-liquid flows are a generic problem posing immense scientific challenges to both academia and industries (e.g. chemicals, consumer goods, food, pharmaceuticals, energy, mining, river engineering, construction, biotechnology, healthcare) with global annual revenues of hundreds of billions of dollars. They enjoy a strong UK position, so process improvements arising from the proposed research could generate multi-million pound savings.

This research will deliver high impact across disciplinary boundaries between many EPSRC research areas (e.g. sensors, instrumentation, fluid dynamics, particle technology, complex fluids and rheology, non-linear systems, continuum mechanics) related to several EPSRC themes: Engineering, Manufacturing the Future, Mathematical Sciences, Physical Sciences and Healthcare Technologies. It will specifically address the "optimising treatment" EPSRC Healthcare Technologies Grand Challenge.

The PG is pre-competitive, aiming to develop novel experimental and theoretical methodologies to address real problems across a wide range of industries and medicine. It is supported by (i) world-leading companies: Unilever (consumer products); Mondelez (confectionery); Campden BRI (all food industry sectors); Briggs of Burton (food/pharma processing equipment); Imerys (minerals); Bristol-Myers Squibb (pharmaceuticals); AstraZeneca (pharmaceuticals); Theragnostics (radiopharmaceutical cold kits); GE Healthcare (medical diagnostics); Siemens (medical imaging); (ii) NHS hospitals (Birmingham Children's, Guy's and St Thomas', and the King's College London PET Imaging Centre); (iii) academic centres in USA, Canada, Hong Kong and South Africa; and (iv) a panel of seven clinical experts.

These partners represent a wide range of commercial/research interests. They will quickly benefit from the new knowledge in their priority areas, and following our dissemination programme, other companies will benefit. The Programme will be developed and implemented with engagement with our partners, both collectively and separately, to address the most pertinent problems relating to engineering and biomedical applications and applications that benefit their businesses and research, as outlined in their letters of support. These collaborations will ensure dissemination, knowledge transfer and impact delivery and will expedite translation of research outcomes into industrial markets and clinical applications. By the end of this PG we anticipate solutions to problems in processing and manufacturing and genesis of new technologies in biomedical engineering, such as a medical PEPT that can be taken to point of care and will impact people's health, new patentable radiotracers that are marketable in the form of "cold kits" for instant radiolabelling on the hospital site, PET scanners able to implement the algorithms developed for clinical use, and particle acceleration analysis software for measuring local arterial blood pressure. We will widen our potential audience by engaging with the relevant sections of the KTN, the High Value Catapult and other research areas (e.g. MRC for medicine, NERC for hydrology). We will also Link with the National Formulation Centre and engage the EPSRC Mathematics in Healthcare Centres at Exeter and Glasgow. Through our Positron Imaging Centre we will attract more users from academia and industry for our new PEPT capabilities.


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