Probing multiscale complex multiphase flows with positrons

To overcome the opacity challenge of multiphase media and their enclosure that limit the usefulness of classical optical methods such as laser Doppler velocimetry and particle image velocimetry, the non-invasive technique called positron emission particle tracking, or PEPT for short was invented and utilised at University of Birmingham and deployed elsewhere too. However, PEPT is a technique in continuous development and has some limitations. Some of the main objectives of this research program include:

• To produce transformative enhancements and innovations in PEPT capability that can lead to improved particle radiochemistry to produce smaller tracers on the micro/nano scale with higher activity per particle and can withstand harsh environments.
• To develop faster, more sensitive and more accurate macroscopic multiphase flow tracking PEPT hardware and software.
• To develop a novel microPEPT analysis system for microscale multiphase flows.
• To address challenges in multiphase particulate flows to enable advances in fundamental engineering science by studying complex 1D flows of multiphase particle-liquid suspensions in pipes, capillaries and microchannels, and 3D flows in mechanically agitated vessels.
• To put forward mathematical innovations in the form of advanced algorithms for PEPT signal processing including simultaneous tracking of multiple particles, new Lagrangian analysis methods for multiphase flows, and new data-driven dynamical models of flow and particle behaviour.

One of the most pressing challenges in modern days engineering is to elucidate and model the missing physics of the multiscale complex particle-liquid flows encountered at the heart of numerous industrial and physiological processes. Recognising this global research challenge, particularly in the all-important fields of engineering and medicine, our vision and ambition in this program is to develop the fundamental physics of complex multiphase particle-liquid flows in a manner that can lead to a step change in our ability to model, analyse, and predict these phenomena.  We will adopt a combination of experimental and theoretical approaches that require a multidisciplinary team of engineers, scientists and mathematicians.

Given the diversity of fields involving multiphase flow systems and the range of associated industrial/medical sectors, the stakes for a step change in elucidating the physics of multiphase flow are quitter high. The output of the project will be disseminated in high quality scientific journals, international, national conferences, workshops and seminars. Supporting companies/organizations will benefit from privileged access to results and advice.

Mostafa Barigou, Principal investigator (Chemical Engineering, University of Birmingham)

Professor Mostafa Barigou is an Emeritus Professor of Chemical Engineering in the School of Chemical Engineering at the University of Birmingham, with particular interests in fluid dynamics, rheology and transport processes with a special focus on complex fluids. The aim of his research is to contribute to the enhancement of fundamental scientific knowledge as well as to provide engineering solutions to all industries concerned.

David Parker, Co-Investigator (Physics, University of Birmingham)

Professor David Parker is a professor of physics who until recently was the director of the positron imaging centre at the university of Birmingham as well as managing the university cyclotron. Has was one of the founding members of the PEPT technique currently used in the programme grant as well as by other researchers at Birmingham and elsewhere in the world. David Parker’s research interests include positron camera development, hardware and software development for PEPT application in academia and industry.

Farid Benyahia, Research Project Lead (Chemical Engineering, University of Birmingham)

Farid Benyahia is a research project lead (project manager) based in the school of chemical engineering at the University of Birmingham. A former professor of chemical engineering with research interests on multiphase reaction systems, membrane distillation and, carbon and brine management.

Phil Blower, Co-Investigator (King’s College London, School of Biomedical Engineering and Imaging Sciences)

Phil Blower is a professor of chemistry holding a chair in imaging chemistry in the division of imaging sciences and biomedical engineering at KCL. His research interests are best summarised as “molecular imaging” mainly using inorganic chemistry tools. Most recently, he has begun to focus on the use of PET to study metallomics and in vivo cell tracking.

Paul Marsden, Co-Investigator (King’s College London, School of Biomedical Engineering and Imaging Sciences)

Paul Marsden is a professor of PET Physics and director of PET Medical Physics at KCL. Paul Marsden has been involved in PET imaging for most of his career and has worked in most aspects of the field. His research interests cover PET methodology and applications
Rafael Torres de Rosales, Co-Investigator (King’s College London, School of Biomedical Engineering and Imaging Sciences)

Rafael Torres de Rosales, Co-Investigator (King’s College London, School of Biomedical Engineering and Imaging Sciences)

Rafael de Rosales is a senior lecturer in chemistry at KCL specialising in the design and synthesis of radiometal-based imaging agents, tracking nanomedicines and therapeutic cells using PET imaging and multimodal imaging (PET-MRI).

Steven Niederer, Co-Investigator (King’s College London, School of Biomedical Engineering and Imaging Sciences)

Steve Niederer is a professor of biomedical engineering at KCL. Steve Niederer’s research aims to combine experimental and clinical data with biophysical computational models to better understand cardiac physiology and pathology to better inform patient selection, treatment and therapy optimisation.

Jacques Vanneste, Co-Investigator (Mathematics, University of Edinburgh)

Jacques Vanneste (left) and Antoine Renaud, University of Edinburgh, Mathematics

Jacques Vanneste is a professor of fluid dynamics in the School of Mathematics at the University of Edinburgh and also the head of its applied and computational mathematics group. Jacques Vanneste’s research work centres around the application of mathematics to fluid dynamics, in particular to the dynamics of the atmosphere and oceans.

Sam Manger, Research Fellow (Physics, University of Birmingham)

Dr Sam Manger is research fellow based in the positron imaging centre in the physics department at the university of Birmingham. Sam Manger’s research interests include hardware and software development for advanced PEPT cameras.

Ananda Jadhav, Research fellow (Chemical Engineering, University of Birmingham)

Dr Ananda Jadhav is a research fellow based in the school of chemical engineering at the university of Birmingham. Ananda Jadhav’s research interests include nanobubbles production, nanobubbles positive identification tools, solids formulation for multiphase flow systems and radioactive tracer encapsulation for PEPT applications. He is also leading CFD simulations of multiphase flows adopting a Lagrangian approach.

Chiya Savari, Research fellow (Chemical Engineering, University of Birmingham)

Dr Chiya Savari is a research fellow based in the school of chemical engineering at the University of Birmingham. Chiya Savari’s research interests include reacting and non-reacting complex multiphase flow systems such as fluidized/spouted beds and solid-liquid suspensions. His new role at Birmingham involves leading multiphase flow probing using PEPT and novel model development of multiphase systems exploiting PEPT data in stirred tanks and pipe flows.

Kun Li, Research fellow (Chemical Engineering, University of Birmingham)

Dr Kun Li is research fellow based in the school of chemical engineering at the University of Birmingham. His research interests include positron emission particle tracking (PEPT) and electrical impedance tomography (EIT) for complex multiphase flow.

Antoine Renaud, Research Fellow (Mathematics, University of Edinburgh)

Dr Antoine Renaud is a research fellow based in the School of Mathematics at the University of Edinburgh. Antoine Renaud’s research interests include the dynamics of the atmosphere and oceans, particle tracking algorithms in PEPT and stochastic modelling of multiphase systems.

Juan Pellico, Research Fellow (Biomedical Engineering and Imaging Sciences, King’s College London)

Hamzah Sheikh, PhD student (Chemical Engineering, University of Birmingham)

Hamzah Sheikh is a PhD student based in the school of chemical engineering at the University of Birmingham. Hamzah Sheikh’s work consists of investigating multiphase flow through experiments and modelling. Typically, this consists of analysing experimental data, verifying models, and commissioning flow rigs using the PEPT technique. The PEPT data analysis will develop further understanding of flow behaviour in multiphase systems.

Aishwara Mishra, PhD Student (Biomedical Engineering and Imaging Sciences, King’s College London)

Aishwara Mishra is a PhD student based at KCL. Aishwara Mishra’s research centres around a pretargeted PET imaging strategy for liposomal nanomedicines based on the Tris(hydroxpyridinone)-Phospholipid conjugate and Gallium-68.

The research program is well structured with themes, work packages and projects within. The themes involve multidisciplinary teams and are led as detailed below:

• Enhancements and innovations in PEPT capability (Led by David Parker and Phil Blower)
• Advances in fundamental and manufacturing engineering science (Led by Mostafa Barigou)
• Advances in biomedical engineering science (Led by Mostafa Barigou and Steven Niederer)
• Mathematical innovations (Led by Jacques Vanneste, University of Edinburgh)

The research team in chemical engineering at the University of Birmingham is developing specialist flow loops to study aspects of multiphase flow (liquid/solid) as well as methods to produce hydrogel particles of various sizes/density capable of encapsulating radiotracers.

Flow loops using a vortex pump and gravity flow platform

Hydrogel solids production setup

Flow loop test section sandwiched between a Gamma-Ray camera panels

Modular camera around a cavity for flow loops at Birmingham

The research team at King’s College radiochemistry and imaging are developing novel radiotracers that will be transferred to Birmingham in due course and be used in advanced particle tracking flow loops.

Radionuclide scanners at King’s College Imaging Chemistry: PET/CT, SPECT/CT

The King’s College teams is engaged in synthesis of different micro/nanoparticles to promote high radiolabeling yields for 68Ga-SiO2 microparticles and develop methods/tools (flow cytometry) for the identification and isolation of microparticles.

At the University of Edinburgh, Prof Jacques Vanneste (CoI) and Dr Antoine Renaud apply innovative mathematical methods to the inversion of PEPT data of the use inferred particle trajectories to uncover fundamentals aspects of multiphase flow dynamics.

Their work so far is focused on:

• the development of a new algorithm for 3D line clustering, based on expectation maximisation, that enables the simultaneous tracking of around 100 PEPT particles
• the inference of global mixing properties of flows from trajectory data, building on the idea of coarse-grained Baysian inference
• the impact of inertia on the dispersion of particles in laminar and turbulent flows

Successive iterations in the expectation maximisation algorithms identifying the location of 5 particles from PEPT data

The programme grant has an advisory board made up of 15 senior people from industry and academia.

• Cyclotron and PEPT Laboratory (Physics, University of Birmingham)
• Fluids laboratory and pilot plant (Chemical Engineering, University of Birmingham)
• High Performance Computing (King’s College London, University of Birmingham, University of Edinburgh)
• PET Radiochemistry centre (King’s College London)