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James J. Riley

Faculty Photo

Professor Emeritus
Mechanical Engineering

Pronouns: he/his/him


Jim Riley, Professor Emeritus in Mechanical Engineering and, until his recent retirement, the inaugural PACCAR Professor of Engineering at the University of Washington, is a fluid dynamicist whose research and teaching emphasize transitioning and turbulent flows. He has worked extensively on a broad range of problems, among them turbulent dispersion, multi-phase flows, boundary layer transition, free shear flows, chemically-reacting flows, ferro-fluid flows, and geophysical flows. He is a pioneer in the development and application of direct numerical simulation to transitioning and turbulent flows. His current research emphasizes turbulent, chemically-reacting flows and also waves and turbulence in density-stratified flows and rotating flows. 

Among his editorial responsibilities, Professor Riley has been an associate editor for the Journal of Fluid Mechanics and for the Applied Mechanics Reviews, and was on the Editorial Committee for the Annual Review of Fluid Mechanics. He was a member of the founding Editorial Board for the Journal of Turbulence and, as Chair of the Division of Fluid Mechanics of the American Physical Society, was instrumental in the founding of the Physical Review Fluids. 

While on sabbatical at Joseph Fourier University in Grenoble, France, Professor Riley occupied the Visiting Chair in Industrial Mathematics. More recently he was a Senior Fellow at the Isaac Newton Institute for Mathematical Sciences at Cambridge University, Cambridge, U.K.  He is a Fellow of the American Physical Society, and was a past Chair (twice) of its Division of Fluid Dynamics. He is also a Fellow of the American Society of Mechanical Engineers, a Fellow of the American Association for the Advancement of Science, and a Fellow of the Institute of Physics.  He is a member of the National Academy of Engineering and of the Washington State Academy of Sciences.


  • Ph.D., Johns Hopkins University, 1972
  • B.S., Rockhurst College, Kansas City, MO, 1965

Select publications

  1. Equation of Motion for a small rigid sphere in a nonuniform flow, MR Maxey and JJ Riley, Physics of Fluids 26(4), 883-889, 1983.
  2. Available potential energy and mixing in density-stratified fluids, KB Winters et al., Journal of Fluid Mechanics, 289, 115-128, 1995.
  3. Secondary instability of a temporally growing mixing layer, RW Metcalfe et al., Journal of Fluid Mechanics, 184, 207-243, 1987.
  4. A subgrid model for turbulent reacting flows, AW Cook and JJ Riley, Combustion and Flame, 112(4), 593-606, 1998.
  5. Direct numerical simulations of homogeneous turbulence in density-stratified flows, JJ Riley et al., Nonlinear Properties of Internal Waves, 76, 79-112, 1981.
  6. Fluid motions in the presence of strong stable stratification, JJ Riley and MP Lelong, Annual Review of Fluid Mechanics, 32(1), 613-657, 2000.
  7. Direct numerical simulations of a reacting mixing layer with chemical heat release, PA McMurtry et al., AIAA Journal, 24(6), 962-970, 1986.
  8. Stratified Turbulence: a possible interpretation of some geophysical turbulence measurements, JJ Riley and E Lindborg, Journal of the Atmospheric Sciences, 65(7), 2416-2424, 2008.
  9. Dynamics of turbulence strongly influenced by buoyancy, JJ Riley and SM de Bruyn Kops, Physics of Fluids, 15, 2047-2059, 2003.
  10. Mixing efficiency in the ocean, MC Gregg et al., Annual Review of Marine Sciences, 10, 443-473, 2018.

Honors & awards

  • Chaire de Mathematiques Industrielles, l’Université Joseph Fourier, Grenoble, France
  • Senior Visiting Fellow, Isaac Newton Institute, Cambridge University
  • Director’s Award, UW Geological Survey
  • Université Paul Sabatier Visitor’s Award, Toulouse, France
  • Senior Scientific Fellow, Battelle Pacific Northwest National Laboratories
  • Honored in Special Session, International Symposium on Stratified Flows
  • ASME Fellow, 2004
  • National Academy of Engineering, 2014
  • Washington State Academy of Sciences, 2012