John F. Brady - Fellow, Elected 2015
John F. Brady
Chemical Engineer
Awarded Bingham Medal 2007
Fellow, Elected 2015
John F. Brady graduated in 1975 from the University of Pennsylvania with a B.S. in Chemical Engineering and, after spending a year at Cambridge University as a Winston Churchill Scholar, entered the Chemical Engineering graduate program at Stanford University where he received an M.S. in 1977, followed by a PhD three-and-a-half years later. His PhD thesis, under the supervision of Andy Acrivos (1994 Bingham Medalist ) dealt with the application of asymptotic analysis to the solution of several fundamental problems in viscous flow theory. Brady joined the Chemical Engineering department at the Massachusetts Institute of Technology as an Assistant Professor. In 1985, he was lured away by Caltech where he has been ever since; first as an Associate Professor (1985 to 1989) and then as Professor of Chemical Engineering (1989 to present). He also served as the Executive Officer of Chemical Engineering at Caltech (1993 to 1999 and again 2013-2019) and was a holder of a part-time Chair in Applied Physics at the University of Twente in the Netherlands (2002 to 2006).
John is known internationally for his seminal and wide-ranging contributions to the study of complex fluids including suspensions, emulsions, colloidal dispersions, ceramics, liquid crystals, ferrofluids, electro- and magneto-rheological fluids. Together with his French collaborator (Georges Bossis) he developed Stokesian Dynamics (SD) — a molecular-dynamics-like method for predicting the microstructural and macroscopic properties of complex fluids. SD ushered in a new era of investigation, not only for suspensions but for multiphase flows generally, in that it allowed one to rigorously solve many long-standing problems and, more profoundly, to pose new questions. Also, a remarkable feature of SD is the spectrum of physical forces (hydrodynamic, electrostatic, colloidal, Brownian, etc.) and the range of both length and time scales (tens of angstroms to centimeters, and microseconds to days) encompassed by one technique. SD has yielded quantitative a priori predictions of suspension behavior that are in excellent agreement with experiments for a variety of systems, ranging from the structure, diffusion and rheology of colloidal dispersions, to yield stresses in electro-rheological fluids, and finally to the self-induced concentration inhomogeneities in pressure-driven flows. A second major contribution is John’s development of a scaling theory for the diffusive and rheological behavior of concentrated colloidal dispersions. Specifically, he has shown, in a series of papers, how the most important effects of hydrodynamics can be included by a simple rescaling of the time or the shear rate by the concentration-dependent self-diffusivity. A third landmark contribution in suspension rheology was the development (with P.Nott) of the so-called suspension balance model to serve as a constitutive equation for the macroscopic description of such systems in complex three dimensional flows.
John has received numerous international awards including the AIChE Professional Progress Award (1998) and the Bingham Medal (2007) of The Society of Rheology, and has been elected to the National Academy of Engineering (1999), the American Academy of Arts and Sciences (2014), and most recently the National Academy of Sciences (2020). In addition, he served as an Associate Editor of the Journal of Fluid Mechanics (1990 to 2004) and served as the Editor of the Journal of Rheology from 2005 – 2010.