April 23, 2007 —
|Michael Kassner, professor and chair of aerospace and mechanical engineering; Tony Maxworthy, professor of aerospace and mechanical engineering; Anatol Roshko, the Theodore von Karman Professor of Aeronautics (Emeritus) at Caltech; and Senior Associate Dean Cauligi Raghavendra, professor of electrical engineering.
The USC Viterbi School Department of Aerospace and Mechanical Engineering’s inaugural Janos Laufer Lecture was delivered by Anatol Roshko, the Theodore von Karman Professor of Aeronautics (Emeritus) at Caltech and a lifelong friend of Laufer’s.
Roshko is a member of the National Academic of Engineering, the National Academy of Sciences, the American Academy of Arts and Sciences, the American Physical Society and the American Institute of Aeronautics and Astronautics. The title of his talk was “Reflections of the Turbulence Problem.”
Roshko said that understanding and trying to explain the fluid mechanics of turbulence was a problem that has long eluded many of the great minds of science since at least the time of Leonardo da Vinci.
Da Vinci took the easy way out. The pictures he drew of turbulence clearly showed the complexity and his fascination with it, and it probably intrigued those who followed.
Both Galileo and Newton found turbulence far more complicated than the motions of the planets or classical mechanics, respectively. In more recent years, the late Nobel Laureate Richard Feynman called turbulence “the greatest unsolved problem of physics.”
Whether it is seen in the wakes of ships or jet aircraft, or the motion of liquids as they course through pipes and channels, turbulence is difficult to describe and quantify. Roshko listed some of the attributes that characterize turbulence.
First there is great disorder and turbulence is random and chaotic. Then there is fluctuation, or an unsteadiness. Turbulence is also multiscale and three-dimensional. It produces giant fast-moving whirls, tiny slow eddies, and everything in between.
During the past 200 years engineers and physicists have begun to make progress in describing turbulence mathematically. One of those cited by Roshko was USC’s Fred Browand, professor of aerospace and mechanical engineering who was in the audience. Another was Laufer. A third was Tony Maxworthy, professor of aerospace and mechanical engineering who had introduced Roshko.
Anatol Roshko, his wife Aydeth, Allison Laufer and Karen Laufer Delaney.
The lecture led to a lively question and answer session with faculty and students making it clear that the quest to understand turbulence was far from over.
“When discoursing about turbulence, don’t take yourself too seriously,” concluded Roshko.
In addition to Roshko’s wife Aydeth, also present in the audience for the first Laufer lecture was Karen Laufer Delaney, Laufer’s daughter; and Allison Laufer, his granddaughter. Roshko said that the two families had been friends for many years and that he was honored to present the first Laufer lecture.
Michael Kassner, professor and chair of aerospace and mechanical engineering at the Viterbi School, noted that Laufer had founded the USC department and chaired it for 19 years.
“He hired extraordinary faculty during that time and made it one of the best aerospace departments anywhere,” said Kassner.