Oldroyd Early Career Award
In commemoration of the scientific achievements of James Gardner Oldroyd, pioneer of rheology, the European Society of Rheology (ESR) decided in 2023 to introduce a “Oldroyd Early Career Award” for outstanding, early-career achievements in the field of rheology and for commitments to the rheological community.
The award is awarded annually and eligible to rheologists regardless of their geographical location.
Awardees
Safa Jamali (2025)
Qian Huang (2024)
Duncan Hewitt (2023)
Oldroyd Awardee 2025
After earning a Master’s degree in rheology through a European Union network-based Masters program (Eurheo), Safa worked primarily with Joao Maia, first at U. Minho (Portugal) and then at Case Western Reserve University, and he was awarded his Ph.D. in Macromolecular Science and Engineering in Spring 2015 in the general area of adapting Dissipative Particle Dynamics (DPD) techniques to simulate the nonlinear flow of rheologically-complex systems such as dense colloidal dispersions. After a two year postdoc at MIT with Bob Armstrong and Gareth McKinley, Safa Jamali was appointed as an assistant professor at Northwestern University in 2017, and promoted to associate professor in 2023.
Safa Jamali has made a wide range of multi-faceted and diverse set of contributions to the science and practice of rheology: from theoretical and fundamental contributions in suspension rheology, to bringing advances in AI/ML technologies to rheology in a meaningful way, and to developing computational and data-driven tools that are of utility to a wide spectrum of rheologists. Safa’s recent work as a junior faculty member at Northeastern University has brought AI/ML to complex fluids and rheology, and developed tools based on AI as robust methods for complex fluid modeling. This work has taken several pathways: from construction and detection of unbiased constitutive models for different complex fluids, to developing multi-fidelity platforms for highly accurate predictions of the rheological behavior of a given system through a general platform called “rheology-informed machine learning”. This recurring theme of his research has resulted in a series of papers in PNAS, Scientific Reports, Soft Matter, Journal of Rheology, as well as in the ESR’s flagship journal Rheologica Acta. Specifically, his work published in JoR (also featured on the cover) in 2021 has been both the most-cited and the most-read article of JOR over the past year, indicating the level of impact it has and will continue to make. Having established himself as a pioneer of data-driven techniques in rheology, Safa recently: (1) wrote a perspective article in the latest issue of the Rheology Bulletin (which appeared during the ICR in Athens), and (ii) co-edited a special issue of Rheologica Acta and wrote an editorial article on the topic which was published in 2023/2024. With the ESR recognizing the essential need in exploring and tailoring these new areas for rheological sciences, Safa has been the primary technical organizer/chair for this topical area at the annual meeting of SOR, as well as at the last ICR meeting in Athens, and continues to spearhead our community’s efforts in this direction.
Safa Jamali
Award Citation: For contributions to the computational simulation and physical understanding of the rheology of dense suspensions and attractive colloidal systems, and for pioneering the development of machine learning techniques and physics-informed data-driven approaches to rheology and our understanding of complex multicomponent systems.
Oldroyd Awardee 2024
Qian Huang is a professor at Sichuan University, China. She is a rheologist, interested in understanding the nonlinear extensional rheology and elastic fracture of polymer liquids as a function of their molecular structures through experimental studies. She received her B.E. from Zhejiang University in China in 2004 and her M.Sc. from the Technical University of Denmark (DTU) in 2006, both in Polymer Engineering. She was then working as a chemical process engineer in Shanghai until the end of 2009. She received her Ph.D. in molecular rheology of complex fluids also from DTU in 2013, under the supervision of Professor Ole Hassager. She continued working at DTU as a postdoc and later a researcher until 2020. In 2021 she joined the Polymer Research Institute at Sichuan University as a professor.
Dr. Qian Huang has contributed substantially to our understanding of the nonlinear extensional rheology of entangled polymers with her state-of-the-art experiments utilizing the filament stretching rheometer. Her early work demonstrated the important difference between entangled polymer melts and solutions in extensional flow through careful and innovative experimental design. By using oligomeric solvents and keeping the same number of entanglements, she unravelled how the extensional rheological behaviour changed from strain-rate thickening to strain-rate thinning with increasing the polymer concentration (Macromolecules 2013, 2015; ACS Macro Lett. 2013; J. Rheol. 2016). Her most recent work further revealed that extensional flow-induced concentration gradient may happen in polymer solutions even with chemically identical solutes and solvents, and its influence on extensional rheology cannot be ignored (ACS Macro Lett. 2023). Dr. Huang also studied extensively on entangled polymer melts with different macromolecular architectures. By combining extensional rheology and ex situ small angle neutron scattering techniques, Dr. Huang and co-workers were able to elucidate theconformation of a three-arm star polymer in fast extensional flow, which explained why its nonlinear rheological behaviour is similar to that of a linear polymer of the same span length (Macromolecules 2016; PRL2018). Later she investigated the extensional rheology of ring polymers and documented their significant strain hardening in extensional flow for the first time (PRL2019). Due to her important contribution in this area, she was invited to write a Perspective on extensional rheology of polymers on Macromolecules in 2022. Another important contribution of Dr. Huang is the investigation on elastic fracture of polymer liquids. By combination of controlled extensional rheology with high-speed imaging, she reports the first images of simultaneous multiple crack propagation in polymeric liquids (PRL 2016; Soft Matter 2017). In her later work, she clarified that the length scale related to elastic fracture is smaller than an entangled strand (Phys. Fluids2019), and further elucidated that chain scissionplays a main role in liquid fracture by combining extensional rheology and fluorescent microscopy (Macromolecules2022). She has also expanded her research area from polymer liquids to glassy polymers, where the influence of chain alignment in polymer liquids under extensional flow on mechanical properties of the subsequently quenched samples is discussed (ACS Macro Lett. 2018, Macromolecules 2019). The above contributions greatly improved our understanding of nonlinear dynamics of polymers and provided important guidance on molecular design of high-performance materials.
Qian Huang
Award Citation: Qian Huang designed and carried out a series of beautiful experiments on studying the nonlinear dynamics of well-defined polymer liquids. By combining extensional rheology and scattering/microscopy techniques, her work provides a fundamental understanding of how molecular parameters at different length scales influence rheological properties and elastic fracture.
Oldroyd Awardee 2023
Duncan Hewitt is Associate Professor at University College London. He is an applied mathematician and rheologist, interested in using mathematics to model and understand physical processes in the world around us most notably for yield stress and other complex fluids. He holds undergraduate degrees (BA and MMath) in Mathematics and a PhD in Applied Mathematics, all from the University of Cambridge. Following the award of his PhD in 2014, he held Research Fellowships firstly in the Department of Mathematics at the University of British Columbia, Vancouver (2014-2015) as a Killam Postdoctoral Research Fellow, followed by a Research Fellowship at Gonville and Caius College, University of Cambridge (2015-2019). In 2019 he was appointed Lecturer in the Department of Applied Mathematics at University College London and promoted to Associate Professor in 2022.
The most significant early contribution of Duncan on the topic of yield stress fluids is with the paper “Viscoplastic boundary layers” published in JFM. In this paper, Duncan and the team revisited one of Oldroyd’s 1947 papers concerned with the same problem. Oldroyd derived a nonlinear form of the boundary-layer equations for a Bingham model but there were significant doubts within the literature that these were actually correct. In revisiting the problem using theoretical and numerical approaches, Duncan and the team were able to demonstrate that the viscoplastic boundary layers postulated by Oldroyd (based on theoretical arguments alone) did form exactly as envisioned by him. Duncan’s strongest contribution to the field is in the area of “swimming” in yield stress fluids. Starting with an analysis of GI Taylor's canonical ‘swimming sheet', idealised versions of squirming organisms, and long, thin worm-like motions have been studied by Duncan, the latter of which involves a generalisation of classical slender-body theory for viscoplastic fluids. Duncan has also made important contributions to our understanding of viscoplastic dam breaks, viscoplastic free surface flow around obstacles, and viscoplastic flow through Hele-Shaw cells featuring various obstructions. In an entirely separate series of papers, he has also made important contributions to our understanding of how rheology affects the compressional mechanics of deformable porous suspensions.
Duncan Hewitt
Award Citation: Dr Duncan Hewitt is an applied mathematician, responsible for a series of beautiful fundamental studies investigating yield stress fluids, most notably for probing locomotion through such “viscoplastic” fluids. Duncan combines rigorous analytical work with high-quality simulations to provide fundamental physical understanding and insight.