Professor Ken Walters FRS





Professor Ken Walters FRS, who has died at the age of 87, was a mathematician, rheologist, mentor and friend. At the time of his death he was a Distinguished Research Professor in the Department of Mathematics and the Faculty of Business and Physical Sciences at Aberystwyth University.

Ken was educated at the University of Wales, Swansea, where he graduated with 1st class honours in Applied Mathematics in 1956, followed by a PhD in the flow of elastico-viscous fluids, supervised by Professor J G Oldroyd.

He came to Aberystwyth in 1960 and was quickly and frequently promoted, being made Professor in 1973. He started a research group here that put Aberystwyth firmly on the rheological map, attracting students, academic and industrial visitors to Aberystwyth, and resulting in an enviable performance for Applied Mathematics in successive Research Assessment Exercises.

Ken was elected Fellow of the Royal Society in 1991, a Foreign Associate of the National Academy of Engineering of the United States in 1995, was a Founding Fellow of the Learned Society of Wales, and a member of the Science Advisory Council for Wales from 2010 to 2015.

His rheology group studied complex fluids such as paints, oils, and polymer melts. The group made pioneering progress on the numerical solution of problems associated with the flow and processing of such materials, and were unusual amongst mathematicians in having a well-equipped experimental laboratory to inspire and validate their theoretical work.

In 1976 Ken was the founding editor of the Journal of non-Newtonian Fluid Mechanics, firmly establishing the journal and stepping down only after the 100th volume was published. Of his several books (and many research articles), An Introduction to Rheology (1989), written with Barnes and Hutton, is still a canonical textbook for advanced students because of its clarity, and Numerical Simulation of Non-Newtonian Flow (1984), written with Crochet and Davies, was pioneering in developing the field of numerical analysis of the flow of complex fluids.

Many colleagues will remember Ken as a senior academic who promoted research excellence, and who nurtured and mentored leading mathematicians and scientists. For Ken and his wife Mary, rheology was an opportunity to travel the world, not only to discuss research, but also to spend time with friends .

In 1991, Ken and others founded the Institute of Non-Newtonian Mechanics, associated with the then University of Wales, providing an opportunity to hold conferences in beautiful parts of the country and bring an international cast of the leading rheologists in the world to Wales. Many of us will miss those events, and in particular we will miss seeing Ken in his role as organiser, scientist, and bon viveur.

Professor Simon Cox, Head of the Department of Mathematics, Aberystwyth University