Abstract
Trying to understand old data on turbulent mass transfer in a cylindrical system with an inner cylinder that rotates forced me to develop a new theory of turbulence. We are interested only in statistical averages. The theory attempts to find local laws governing the relationships among various statistical averages of turbulence, such as the eddy viscosity and the volumetric dissipation. Coupled with suitable boundary conditions, these comprise a well posed mathematical problem whose solution gives the desired information.
This so-called dissipation theorem is being applied to four systems―rotating cylinders, pipe flow, flow past a flat plate, and a rotating disk―for which good data are available. There has been a fruitful interplay between theory and experiment. The information from experiments is essential to guide the theory, which in turn explains the experiments. The goal is one theory with one set of parameters to explain many diverse systems. This has worked out very well and is the main subject of this talk.
The viscous sublayer is directly related to the main topic. I have been bothered for more than four decades with the question of whether the eddy viscosity is proportional to y3 or y4, where y is the distance from a solid wall. Theoreticians say one, and experimentalists find the other.
The viscous sublayer is so thin, and the turbulence has decayed to such an extent, that eddies of the turbulence behave independently of each other. This permits application of Fourier transforms to explain the profile of the eddy viscosity and also that of the eddy diffusivity very close to the wall. Fourier transforms can then explain how the eddy diffusivity can vary with both the cube and the fourth power of the distance from the wall.
A surprising result of the dissipation theorem of turbulence is the explanation of why the measured friction factors in turbulent pipe flow cannot be calculated from the measured eddy viscosities.
These diverse aspects of turbulence are reviewed in this talk.
Bio
John Newman earned his B.S. in Chemical Engineering in 1960 from Northwestern University. While at Northwestern, Newman was an engineering co-op student at Oak Ridge National Laboratory, where he worked on diffusion in ion exchangers and solvent extraction.
Soon after Newman entered the University of California at Berkeley for graduate study, he obtained his master's degree, on current distribution in porous electrodes, under the guidance of Charles Tobias. While Newman was a Ph.D. student, he contributed to the preparation of major portions of the English edition of Levich's book, Physicochemical Hydrodynamics, published in 1962.
Shortly after receiving his doctorate, Newman joined the faculty at U.C. Berkeley and became a full professor in 1970. He had won the Young Author's Prize for his work on current distribution on a rotating disk below the limiting current. This paper was also recognized in Current Contents as a Citation Classic. In 1969 Newman again won the Young Authors' Prize for his work with his student William Parrish on modeling channel electrochemical flow cells. In 1985 Newman received the David C. Grahame Award of the Physical Electrochemistry Division of the Society. Newman's book, Electrochemical Systems, published in 1973 with a fourth edition about to come out in 2020, is used throughout the world as a monograph and graduate text in electrochemical engineering. Also related to education is the Henry B. Linford Award for Distinguished Teaching, which the Society granted in 1990.
In addition to his numerous publications, reviews, and lectures, Newman has made many contributions to electrochemical technology through his consulting work. The significant improvement of the grid design for the lead-acid battery was a result of his collaboration with Johnson Controls. With colleagues at Argonne National Laboratory, and with his students, Newman developed a model of the high temperature LiAl-FeS battery.
Newman was also Faculty Senior Scientist and Principal Investigator in the Environmental Energy Technologies Division of Lawrence Berkeley National Laboratory. Recently, he has studied corroding and passivating systems, methods for removal of metal ions from dilute waste streams, and concentration and potential profiles in reacting systems. From June, 1990, to2000, Newman was an associate editor for the Journal of the Electrochemical Society.
Host: Professor Kyle Smith
