European Society of Rheology (ESR)

The European Society of Rheology is open for everyone interested in rheology in all countries of Europe. Rheology is defined as the science of the deformation and flow of matter which means that rheology in some form enters almost every study of material properties. The ESR involves rheologists engaged in both industrial and academic research and development and is therefore a common meeting ground for engineers, physicists, chemists and biologists with a common interest in rheology

Olivier Pouliquen is the 2024 Weissenberg Awardee

Olivier Pouliquen is a CNRS research director at the Institut universitaire des systèmes thermiques industriels (IUSTI, CNRS/Aix-Marseille University). After his studies at the Ecole Normale Supérieure, he completed a thesis on fluid mechanics and instabilities at the École Polytechnique under the supervision of Patrick Huerre and Jean Marc Chomaz, before turning to the physics of granular media during a postdoctoral period with S. Savage in Montreal. Recruited by the CNRS in 1995, he has since worked on divided media at IUSTI, studying granular materials and dense suspensions in search of a continuous description of these complex media with their fluid-solid behavior.

Olivier Pouliquen’s contributions to the understanding of the mechanics of flowing granular materials and concentrated suspensions are pioneering. Bringing together concepts from rheology and fluid mechanics, and combining experimental and modeling approaches, Olivier Pouliquen has established the constitutive laws of dense granular flows and applied his concept of “imposed pressure rheology” to concentrated suspensions, thus unifying the rheology of dry granular flows and dense suspensions. His major contributions to the field include the study of granular compaction and the identification of a crystallization mechanism by cyclic shear deformation, with analogies to the physics of glasses; the demonstration of original instabilities in granular flows, both in the dense and gas regime; the extension of the Reynolds dilatancy law to flowing media, with important consequences for avalanche triggering; or the development of non-local constitutive laws for granular and amorphous materials. In recent years, his work on granular rheology has been extended to systems as diverse as dense colloids, powders, cohesive materials, and biological fluids, illustrating the continuing originality of Olivier Pouliquen's research since the beginning of his scientific career.

Through his individual research and his leadership of the GdR MiDi (Groupement de Recherche Milieux Divisés, French National Network on Granular Media), Olivier Pouliquen has been instrumental in establishing the European mechanics community at the forefront of developments in understanding the rheology of granular flows. His book “Granular media: between fluid and solid”, published by Cambridge University Press in 2013, has also been pivotal in bringing the knowledge of granular media to a wide audience.

Olivier Pouliquen was director of the Milieux divisés research group from 2000 to 2008, director of the Fabri de Peiresc association from 2014 to 2018, and director of IUSTI from 2018 to 2022. He has been Associate Editor of the Journal of Fluid Mechanics since 2011.

His honours include being awarded Fellow of the European Fluid Mechanics Society in 2011, the Louis Ancel Prize of the Société Française de Physique (SFP) in 2014, the Grand Prix Mergier Bourdeix of the Académie des Sciences in 2017, and the CNRS Silver Medal in 2018.

Award Citation:

The work of Olivier Pouliquen in rheology is at the very foundation of our understanding of the flows of granular materials.

Qian Huang is the 2024 Oldroyd Early Career Awardee

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; PRL 2018). Later she investigated the extensional rheology of ring polymers and documented their significant strain hardening in extensional flow for the first time (PRL 2019). 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. Fluids 2019), and further elucidated that chain scissionplays a main role in liquid fracture by combining extensional rheology and fluorescent microscopy (Macromolecules 2022). 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.

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.

Access to Rheologica Acta

Access to Rheologica Acta and Applied Rheology is free for all individual members of the ESR. Please access Rheologica Acta via the 'Member area'.

All participants of AERC 2022 (Seville/Spain) are automatically individual members of the ESR until August 2023.

Rheologica Acta Publication Award

At every AERC or ICR, the editors of Rheologica Acta present the publication award sponsored by Anton Paar. This award gets selected by three editorial board members based on a preselection by the editors and is aimed to highlight the type of work which the journal likes to see published.

The 2024 Rheologica Acta Publication Award is given to: Elisabeth Lemaire, Frédéric Blanc, Cyrille Claudet, Stany Gallier, Laurent Lobry, François Peters: Rheology of non-Brownian suspensions: a rough contact story, Rheologica Acta 62 (20223) 253-268.

The entire list of the Rheologica Acta Publication Awards and the Weissenberg Lecture papers can be found in the Archive.