The Australian Society of Rheology (ASR) awards the ASR Medallion to members whose contributions to rheology have been internationally recognised as outstanding and meritorious. Thus far, the Medallion has been awarded to:

Professor Billy Todd and Professor Peter Daivis


Professor Ravi Prakash Jagadeeshan


Professor Raja Ramesh Huilgol


Professor Tamarapu Sridhar


Professor Satinath N. Bhattacharya


Professor Nhan Phan-Thien


Professor David Vernon Boger


Professor Roger Ian Tanner


Award nominations are accepted by sending an email to the ASR Council at This email address is being protected from spambots. You need JavaScript enabled to view it.

To be eligible the applicant must be a permanent resident in Australia, and a member of the ASR. The criteria are defined in the ASR's Constitution annexe (Page 4).


The ASR Medallion was created by renowned Australian sculptor Michael Meszaros following consultation with the ASR. Michael described his ideas which lead to the final design as:

ASR Medallion

Rheology is concerned with both the characteristics of fluids and the human control of these characteristics. Knowledge of these factors allows rheologists to utilise both to achieve a designed result.

The medal shows an elastic fluid emerging from a pipe, controlled by a valve. The fluid falls into a cupped pair of hands, which guide the overflow to spill over the edge of the medallion.

Thus there is a depiction of the mechanical control of a fluid, the human control of the fluid and an expression of the characteristics of the fluid itself.

Sculptor Michael Meszaros
Sculptor Michael Meszaros, who designed the ASR Medallion in consultation with the ASR.

Professor Roger Ian Tanner: 1993 medallion recipient

The Inaugural Australian Society of Rheology (ASR) Medallion was awarded in 1993 to Professor Roger Ian Tanner.

Roger Tanner completed a Ph.D (Mechanical Engineering) at Manchester University in 1961 and commenced his academic career at the University of Sydney, followed by an Associate Professorship at Brown University. In 1975 he returned to the University of Sydney as the fifth P.N. Russell Professor of Mechanical Engineering, alternating as the Head of Mechanical Engineering from 1977 to 1989.

Professor Tanner published two seminal works on extrusion: “A Theory of Die-Swell” (1970) and “The Solution of Viscous Incompressible Jet and Free Surface Flows Using Finite Elements” (1974). These works are widely cited and considered the beginning of computational rheology, which has had a major impact on the field of rheology.

Professor Tanner began working on computer simulations of non-Newtonian flows in 1972. In 1977, he co-developed the PTT (Phan-Thien–Tanner) model, a new constitutive equation derived from Network Theory, which has been widely cited and used by academics and industry. Professor Tanner continued his research at the University of Sydney becoming interested in suspension rheology.

Professor Tanner served on the editorial boards for Computational Mechanics, the Korea-Australia Rheology Journal, the Journal of Non-Newtonian Fluid Mechanics, Rheologica Acta, Applied Rheology, and the Royal Society of London Open Science. In addition to his textbook “Engineering Rheology”, Professor Tanner has published another 3 books, 11 book chapters, 270 refereed Journal papers and 88 conference manuscripts on a broad range of topics.

Professor Roger Tanner was awarded the 1993 ASR Medallion for his pioneering viscoelastic flow and extrusion process research, his support of the ASR, and his active membership of conference organising committees, which included chairing the 1988 International Congress on Rheology.

His contributions to rheology and engineering were also acknowledged by the Edgeworth David Medal - Royal Society of NSW (1966) and the Gold Medal from the British Society of Rheology (2000). He was elected Fellow of the Australian Academy of Technological Sciences (1977), Australian Academy of Science (1979), the Australian Academy of Technological Sciences and Engineering (1987) and the Royal Society of London (2001) and received an Honorary Fellow of Engineers Australia and the American Society of Mechanical Engineers.

In 2005 Professor Tanner was awarded with an ASR honorary life membership.

Nhan Phan-Thien with Roger Tanner circa 1997
Dr. Nhan Phan-Thien and Dr. Roger Tanner, circa 1997, with the microfourier rheometer that they helped to develop.

Professor David Vernon Boger: 1994 medallion recipient

Professor David Boger was awarded a Ph.D (Chemical Engineering) in 1965 from the University of Illinois, and then commenced his academic career at Monash University (Department of Chemical Engineering).

In 1982 he accepted a Professor position at University of Melbourne Chemical Engineering Department where he held various positions including Deputy Dean - Faculty of Engineering; Associate Dean (Research) - Faculty of Engineering; Deputy Director, Advanced Mineral Products Centre; and Research Program Leader, Co-operative Research Centre for Industrial Biopolymers.

Professor Boger's rheology research ranges from basic polymer and particulate fluid mechanics to applications in the minerals, coal, oil, food and polymer industries.  One of his significant achievements was the development of 'Boger fluids'. These constant viscosity elastic liquids have provided invaluable insights into the extensional rheology of polymer solutions.

During this period Professor Boger received the Annual Award - British Society of Rheology (1983), Royal Society of Victoria Medal for Research (1985), Fellow - Australian Academy of Technological Sciences and Engineering (1989),ESSO Award for Excellence in Chemical Engineering (1991), Fellow - Australian Academy of Science (1993), and the Pol Eureka Prize for Environmental Research (1993).

The 1994 Australian Society of Rheology (ASR) Medallion was award to Professor David Vernon Boger for his significant contribution to viscoelastic flow research, his instrumental contribution to establishing the ASR and his ongoing support for the ASR and the international rheology community. For example, he served as the Australian Delegate to the International Committee on Rheology (1978 to 1983 and 1990 to 2004).

Since receiving the ASR Medallion Professor Boger’s contributions have been acknowledged by the CSIRO External Medal "for research excellence" (1998), the CHEMECA Medal (2000), the Victoria Prize (2002), the  British Society of Rheology Gold Medal (2004) and elected a Fellow of the Royal Society (2007).

In 2005 Professor Boger was awarded with an ASR honorary life membership and the Prime Minister's Prize for Science. 

Professor Nhan Phan-Thien: 1997 medallion recipient

Professor Nhan Phan-Thien was awarded a PhD (Mechanical Engineering) at the University of Sydney in 1979. His academic career commenced at the University of Newcastle before moving to the University of Sydney where in 1991 he was appointed to a Personal Chair in Mechanical Engineering.

In 1977, he co-developed the PTT (Phan-Thien–Tanner) model with Professor Roger Tanner, the Inaugural Australian Society of Rheology (ASR) Medallion recipient. Then in 1982 he was awarded the Edgeworth David Medal by the Royal Society of New South Wales for distinguished research in science amongst younger workers in Applied Mechanics.

The Australian Society of Rheology Medallion was award to Professor Nhan Phan-Thien in 1997 for his outstanding contributions to non-Newtonian fluid mechanics, computational and constitutive modelling. His work on the stability of torsional flows and cone-and-plate flows had important implications for experimental rheology. His computation research led to a pioneering die design method, and the 1997 Gordon Bell Prize for computing applications.

In 2000 Professor Nhan Phan-Thien moved to the National University of Singapore, where he currently holds a Professorship in Mechanical Engineering. He was elected a Fellow of the Australian Academy of Science in 1999, the European Academy of Science in 2002, and the ASEAN Academy of Engineering and Technology in 2016, and awarded the 2003 Centenary Medal by the Australian Governor General, for service to Australian society and science in Mechanical Engineering.

He was the founding chair in Bio-Engineering Division, which later becomes known as Biomedical Engineering Department at the National University of Singapore. He held visiting professorships in Los Alamos National Laboratory, New Mexico, US, CalTech, California, US, and Stanford University, California, US, a Qiushi Chair Professor at Zhejiang University, Hangzhou, China, an Adjunct Professor at the University of Southern Queensland, Queensland, Australia, and an honorary professor at the University of Sydney, Sydney, Australia.

Professor Nhan Phan-Thien has published more than 350 technical papers and five books. In 2017 the third edition of “Understanding Viscoelasticity: An Introduction to Rheology“ was published.

Prof. Nhan Phan-Thien today
ASR Medallion recipient Prof. Nhan Phan-Thien circa 2004, now based at the National University of Singapore.
Nhan Phan-Thien's Ph.D. graduation, with Roger Tanner
Nhan Phan-Thien graduating from his PhD in Mechanical Engineering at Sydney University circa 1979, with Roger Tanner.

Professor Satinath N. Bhattacharya: 2013 medallion recipient

Professor Satinath N. Bhattacharya was awarded the ASR life membership in 2008, and the ASR Medallion in 2013, for his services to the ASR, education and the advancement of polymer rheology research.

After completing his Ph.D at the Monash University, Sati commenced lecturing at the RMIT University in 1975, receiving many teaching - learning awards. He was the head of Chemical Engineering in 1990 and 1991 and has been a Professor of Chemical Engineering since 1994.

In 1988 he established the RMIT Rheology and Materials Processing Centre (RMPC) and became its Foundation Director providing leadership until 2008. The RMPC established RMIT University as a polymer extensional viscosity research leader, developing technology which supported the Australian Polymer Industry. During this time Sati developed and built the first extensional rheometer for polymer melts in Australia. In 2000 Professor Bhattacharya extended the RMPC research into polymer nanocomposite and then nanopigments. The centre is internationally recognised for this research and its commercial nanopigment product development program.

In 1992 Professor Bhattacharya became the foundation program leader of the collaborative research centre (CRC) for Polymers, which undertook polymer processing and recycling industry-collaborative projects.

Professor Bhattacharya research areas include concentrated dispersion rheology, coal slurry preparation and transport, polymer rheology, polymer processing and waste recycle, polymer nanocomposites and nanopigments. His broad interest is reflected in the authored / co-authored 340 journal and conference papers, and the textbooks “Rheology: Fundamentals and Measurements” (1997) and “Polymeric Nanocomposites-Theory and Practice” (2007). He also has extensive research student supervision experience, overseeing forty Ph.D and ten masters students.

From 1979 until 1986 Professor Bhattacharya was an active member of the ASR council, holding secretary, vice-president and president positions. His rheology and polymer community support includes:

  • Editorial Board Member (International) - Polymer Processing Journal and Journal of Polymer Engineering
  • Rheology committee chair - Standard Association of Australia (1986 to 1988).
  • Executive committee member - International Polymer Processing Society.
  • Co-organiser - 2nd Pacific Rim Conference on Rheology (1997).
  • Chair, International conference on Polymer Processing and Rheology (PPS-19) (2003).
  • Co-Chair - Nanotechnology Symposiums: PPS-21 (2005) through to PPS-29 (2013).
  • Chair - International Symposium on Nanostructured Materials (2009).

He is a fellow in the Institution of Chemical Engineers (U.K.), an honorary fellow in the Indian Institution of Chemical Engineers and a member of the Society of Rheology (U.S.A.).

Recently, he was been President elect of the international Polymer Processing Society (PPS).

David Boger, Sati Bhattacharya and Roger Tanner at 2013 AGM

ASR Medallion recipients Prof. David Boger, Prof. Sati Bhattacharya, and Prof. Roger Tanner, at the 30th anniversary AGM in July 2013.

Professor Tamarapu Sridhar: 2014 medallion recipient

Professor Tamarapu Sridhar was award the ASR Medallion in 2014 at the 6th Pacific Rim Conference on Rheology, which included a special symposium in his honour.

The ASR Medallion was award for his distinguished research, teaching and community service and his profound and lasting rheology contributions, which have showcased Australian rheology to the world. Professor Sridhar played a significant role in nurturing the ASR community and was a founding Korea-Australia Rheology Journal co-editor and remained its editor from 1999 until 2003.

After receiving his PhD in 1978 from Monash University, and short tenure teaching positions at Monash University and the State University of New York at Buffalo, he returned to a senior lecturer position at Monash University. In 1992, Tamarapu successfully applied for a professorial position within the Department of Chemical Engineering and later became Head of the Department. At the end of 2002, Professor Sridhar entered his current role as Dean of the Faculty of Engineering.

Sridhar has supervised over twenty successful Ph.D.s, won over forty competitive research grants and published over 140 papers. Over the past seven years, he has established a joint venture Research Academy at Bombay with over 100 Ph.D students which was expected to grow to 300 students.

In 2012 Professor Sridhar Tamarapu was made an Officer in the Order of Australia (AO) for his distinguished service to tertiary education, particularly the discipline of chemical engineering, and to the forging of international strategic educational relationships.

Professor Sridhar is a Fellow of Engineers Australia, the Australian Academy of Technological Sciences and Engineering, the Institution of Chemical Engineers (UK) and the Australian Academy of Science. He was selected among the one hundred most influential engineers in Australia by Engineers Australia (2004 - 2006). He was made an Honorary Fellow and awarded the GP Kane Award by the Indian Institute of Chemical Engineers.  He was awarded the Australian Centenary Medal for service to Australian society and science and the ESSO Energy Award for outstanding contribution in the field of chemical engineering. In 2004, he was Chair of the Institution of Chemical Engineers (Australia) and served as a member of the ARC Panel on Engineering.

Professor Sridhar's most significant scientific contribution is the development of the filament-stretching rheometer for measuring the extensional properties of solutions. The instrument has been adopted by several leading rheological laboratories, featured in textbooks and the technique is regularly taught. A review of this instrument and its impact on the development of rheology is given in several recent papers (for example G.H. McKinley, “A decade of filament stretching rheometry”, Plenary Lecture, Int. Rheol. Cong., Cambridge, 2000). Professor Larson in a recent review (“The rheology of dilute solutions of flexible polymers: Progress and problems”, J. Rheol., Jan 2005) cited the filament stretching device as one of the four key advances in rheology in the last two decades.

Professor Sridhar also developed the test fluid M1 (named after Monash University) which the Journal of non-Newtonian Fluid Mechanics devoted an entire volume to the study of this fluid. A large number of Ph.D dissertations from around the world have utilised the M1 fluid to test emerging ideas in polymer physics and fluid mechanics. Professor Sridhar also has had a distinguished career in the field of Reaction Engineering simultaneously with his seminal work in rheology. For instance, the prestigious Journal, Industrial and Engineering Chemistry selected Sridhar’s paper (Ind. Eng. Chem. Fund., 19, 21-26, 1980) as one of the 90 most cited papers as part of their 90th year celebrations.

ASR Medallion recipient Prof. Tamarapu Sridhar (left) receiving the award from Dr. Mark Coghill (right) at the AGM in July 2014.

Professor Raja Ramesh Huilgol: 2017 medallion recipient

The Australian Society of Rheology (ASR) council unanimously endorsed the recommendation to award the ASR Medallion to Professor Raja Ramesh Huilgol, Professor of Mathematics (School of Computer Science, Engineering and Mathematics) at Flinders University.

Professors Huilgol’s nomination was supported in testimonials by world-leading rheologists Professor Ken Walters, Professor Nhan Phan-Thien, Professor Ian Frigaard, Professor Tam Sridhar and Professor David Boger and Professor Roger Tanner, his Ph.D advisor.

The medallion was presented in 2017 at the 9th Australian-Korean Rheology Conference in recognition of Professor Huilgol’s outstanding and meritorious contributions over several decades to the science and technology of rheology and the role he has played in highlighting the strength of Australian Rheology to the world.

Raja Huilgol was awarded a Ph.D (Mechanical Engineering) in 1969 at the University of Sydney and later took a position at the Flinders University where he held various academic and administration positions, including Dean of School of Information Science and Technology. He was promoted to Professor in 2008.

His research interests are broad, and include Hopf bifurcation in the dynamics of trains; finite elasticity; viscoelastic fluid mechanics; oxygen diffusion in marsupial brains; inverse methods in photosynthesis; pantograph-cable interaction in very fast trains and injection moulding of viscoplastic fluids.

Professor Huilgol achievements include a Senior Fulbright Scholar at the California Institute of Technology (1983), and a CNRS Senior Visiting Professor at the University of Paris VI (1983), and at the University of Grenoble, France (1996 and 2000). He is a Fellow of the Australian Mathematical Society and was a member of Korea-Australia Journal of Rheology editorial board (1999 to 2008). He authored “Fluid mechanics of viscoelasticity: general principles, constitutive modelling, analytical and numerical techniques” with Professor Phan-Thien. His seminal textbooks were “Continuum mechanics of viscoelastic liquids” and “Fluid Mechanics of Viscoplasticity”.

Professor Huilgol published a significant body of journal articles on a broad range of subjects related to rheology, including major contributions to the understanding of the kinematics of viscoelastic flows. He has also made significant contributions to the understanding of flows occurring in injection moulding processes which benefited Australian industry. He also reduced grain losses due to pulverisation in silos leading to the Silver Medal of the Mexican Society of Rheology in 2001.

Prof. Huilgol with his family after being presented with the award at the AKRC in Sydney in 2017

Professor Ravi Prakash Jagadeeshan: 2020 medallion recipient

The 2020 ASR Medallion recipient was Professor Ravi Prakash Jagadeeshan in recognition of his outstanding and meritorious contributions to rheology and for his many years of distinguished service to the Society and the rheology community in Australia. His nomination was supported by testimonials from world-leading rheologists, including Professor Tam Sridhar and Professor David Boger.

Ravi Jagadeeshan obtained his Bachelor of Technology (Chemical Engineering) from the Indian Institute of Science, a Master of Science (Chemical Engineering) from the University of Akron and completed a PhD (Chemical engineering) at the Indian Institute of Science in 1989.  He undertook postdoctoral and research positions at the National Chemical Laboratory Pune (India), Cavendish Laboratory at the University of Cambridge (UK) and the Swiss Federal Institute of Technology Zurich (Switzerland). He was a Humboldt fellow at the Technical University of Kaiserslautern from 1999 to 2000, and in 2001 joined Monash University.

Professor Jagadeeshan currently heads the Molecular Rheology group within the Department of Chemical Engineering at Monash University. His group is focussed on developing a theoretical and computational description of the flow behaviour of polymer solutions using a using a multiscale approach that combines molecular simulations at the mesoscopic scale with continuum simulations on a macroscopic scale.  He is also interested in applying methods of soft matter physics to studying problems in biology.

Professor Jagadeeshan's major scientific contribution lies in using theory and simulations to explain the molecular origins of the universal rheological behaviour of unentangled polymer solutions that is experimentally observed in strong shear and extensional flows. His work has greatly improved our understanding of the role played by the intricate coupling between macromolecular characteristics such as chain length, flexibility and branching, and intra- and inter-molecular interactions, such as self-avoidance, solvent-mediated hydrodynamic interactions, electrostatic interactions and hydrophobic interactions, in determining macroscopic rheological behaviour of polymer solutions. Working with experimentalists to carefully test theory has been a hallmark of his work.

Professor Jagadeeshan has been the joint editor of the Korea Australia Rheology Journal since 2008. He served on the Society's Council for several years, including the President position from 2006 to 2008. He has also served on the organizing committees of the Pacific Rim Rheology Conference in 2014, the Australia-Korea Rheology Conferences and the Technical Programming committee of (US) Society of Rheology annual meetings and is the Australian representative on the International Committee on Rheology for organizing the International Congresses on Rheology.

Prof. Jagadeeshan (left) receiving the award from Dr. Anthony Stickland (right) in February 2021

Professor Billy Todd and Professor Peter Daivis: 2023 medallion recipient

The Australian Society of Rheology (ASR) awards the ASR Medallion to members whose contributions to rheology have been internationally recognised as outstanding and meritorious. In its entire history, ASR has awarded only 7 Medallions to exceptional Australian rheologists. This year (2023), the ASR Award Committee has awarded a Joint ASR Medallion to two distinguished rheologists for the first time in its history.

The Australian Society of Rheology is delighted to jointly award the ASR medallion for 2023 to Professors Peter Daivis and Billy Todd in recognition of their extraordinary creative collaboration over three decades that has resulted in exceptional and admirable contributions to rheology and for their many years of distinguished service to the Society and to the rheology community in Australia.

Prof. Billy Todd (left) and Prof. Peter Daivis (right)      

Professors Daivis and Todd have spearheaded the development of non-equilibrium molecular dynamics simulations (NEMD) and are pioneers in the rigorous application of NEMD to the fluid dynamics, rheology and tribology of simple and complex fluids. Their work has led to the efficient computation of pressure tensors, heat flux vectors and transport coefficients for periodic systems and highly confined nanofluids. Amongst many examples of their remarkable ability to apply Statistical Physics to rheological problems, particularly noteworthy are their invention of the ‘Method of Planes’ technique for describing highly confined fluids, their contributions to the development of the 'Transient-Time Correlation Function’ methodology for extracting nonlinear rheological properties with reduced statistical noise, and their solution of the problem of simulating steady state elongational flows in periodic boundary conditions. Many of the methods introduced by Daivis and Todd have been included in modern software packages such as GROMACS and LAMMPS. Undoubtedly, the sustained and creative collaboration of Professors Daivis and Todd has profoundly impacted the evolution and the state-of-the-art of Molecular Rheology.

Professors Daivis and Todd have tirelessly dedicated themselves to supporting and promoting the interests of the rheology community in Australia. They have both served on the Society's council and the editorial board of the Korea-Australia Rheology Journal for several years. Daivis has been the Treasurer, Auditor for the Society, and Co-Editor-in-chief of the Korea-Australia Rheology Journal since 2021. Billy Todd was the President of the Society from 2008 to 2010, while Peter Daivis served as President from 2016 to 2018.

Professors Todd and Daivis were presented with the Medallions during a dinner function at the 12th Australia-Korea Rheology Conference (AKRC2023) in Melbourne. On behalf of the Australian Society of Rheology, we congratulate Peter and Billy on their distinguished achievement.