Philip Geoffrey Saffman, an influential teacher and noted researcher in fluid mechanics, died peacefully after a long illness on Sunday, August 17, in Pasadena. He was 77 years old.
Saffman, the Theodore von Kármán Professor of Applied Mathematics and Aeronautics, Emeritus, at the California Institute of Technology, studied vortex instability and the dynamics of arrays of vortices. In particular, he looked into the phenomenon of viscous fingering, which became known as the "Saffman-Taylor Instability." This occurs when a low-viscosity fluid is injected into a higher-viscosity fluid.
His work with vortices also led him to a new mathematical analysis of the wake turbulence caused by jets as they take off, resulting in a theory describing the conditions behind several aircraft accidents.
Saffman was born in Leeds, England, and received his BA, MA, and PhD from the University of Cambridge. In 1964 he accepted Caltech's appointment as a full professor in fluid mechanics within the Division of Engineering and Applied Science. He was named von Kármán Professor in 1995.
He was a Fellow of the American Academy of Arts and Sciences and in 1988 was elected a Fellow to the Royal Society, England's premiere scientific organization. He also received the Otto Laporte Award from the American Physical Society.
Saffman served as associate editor for both the Journal of Fluid Mechanics and Physical Review Letters and was most recently an editorial board member for the journal Studies in Applied Mathematics.
Saffman is survived by his wife, Ruth; children Louise, Mark, and Emma; and grandchildren Timothy, Gregory, Rae (née Sarah), Jenny, Nadine, Aaron, Miriam, and Alexandra.