INTRODUCTION
RICHARD 1. NUNGE
Flow Through Porous Medid Sixth State-of-the-Art Summer Symposium, June 9-11,1969 The Cdrnegie Institution, Washington, he unifying theme of the review papers comprising
Tthe Symposium on Flow Through Porous Media is the movement of material in and through both natural and man-made porous beds of solids. Because of the occurrence of porous media in a wide variety of important practical applications, such flows are the concern of workers in several diverse areas. By assembling a group of review papers relating mainly to the basic phenomena involved rather than papers on isolated applications, the symposium attempts to be general in scope so that the needs of as broad a n audience as possible might be served. Thus the overall objective of the symposium is to provide a critical survey of the techniques, both experimental and analytical, which are useful in treating many of the problems which involve flow through porous media. For the most part, the symposium papers are concerned with factors affecting the “flow phenomenon” aspect of the transport processes occurring in porous media, although some applications in separation processes are described. A partial list of the topics discussed includes : the structure of porous media, methods of determining pore structure, anisotropy, the relationships between microscopic and macroscopic theories, high Reynolds number flow, diffusion and flow of gases, dispersion, miscible displacement, non-Newtonian fluid flow, multiphase flow in liquid-liquid and solidliquid systems, capillary action, and reverse osmosis. Perhaps if one point is made clear in the symposium, it is that little can as yet be predicted from first principles about problems related to flow in porous media. T h e phenomenological approach, as exemplified by Darcy’s
D.C.
law, has long proved useful in handling such problems and will undoubtedly continue to d o so in the future. However, inroads are being made toward more complete descriptions so that working equations may be extrapolated to new situations with confidence. But, in the final analysis, theory must be closely integrated with experiment for verification and evaluation of undetermined parameters. I n this sense, problems involving flow through porous media are akin to problems involving turbulent flow. While each area has been studied over a long time period, there still exists the possibility of fundamental breakthroughs in the theory. This, then, summarizes the critical and challenging properties of the subject area, namely to find better working correlations to deal with the everyday practical applications and simultaneously to search for a deeper fundamental understanding. T h e symposium reflects on both the theoretical and applied aspects of the state of development. Because this is primarily a review symposium, one should find much that is well-known to the experienced worker gathered together and hence it should prove useful for instruction in basic concepts. At the same time, current developments are described so that the symposium papers should serve as a guide to reading the recent literature and to evaluating the future literature. After the papers are published in I&EC over the coming months, they will be collected in one bound volume for reproduction by the American Chemical Society. I t is believed that this book will prove to be a valuable reference source to practicing engineers, scientists, educators, and students.
Dr. Richard J . Nunge, chairman of the Annual Review of Fluid Dynamics. Dr. Nunge is a member of the American Institute of Chemical I H E C Division Symposium on Flow Through Engineers, the Institute of Colloid and Surface Porous Media, is Associate Professor of Chemical Science, Sigma Xi, and A A U P . Engineering at Clarkson College of Technology, Potsdam, N . Y., 13676. He was Assistant Dr. Nunge wishes to acknowledge, with Professor at Clarkson from 1965 to 1968 and thanks, the contributions of Professors Thomas J . Hanratty and Howard Brenner who prebefore that was Instructor in Chemical Engineering at Syracuse University from 1962 to 1964. sented invited talks entitled “Flow Field in a Bed of Spheres at High Reynolds Numbers” and Dr. Nunge obtained his B.Ch.E. at Syracuse “An Evaluation of the February 1969 I.A.H.R. University in 7960, his M.Ch.E. from Syracuse (Haifa) Meeting on Transport Phenomena in in 1962, and his Ph.D. from Syracuse University DR. RICHARD J. NUNOE in 1965. Porous Media,” respectively. Thanks are also Professor Nunge has published a number of papers in the due to Mrs. Bonnie Watkins of the s t a j of Industrial and Enareas of gas-liquid kinetics, multistream heat transfer, and gineering Chemistry for her help in organizing all physical dispersion. He is currently one of the authors of I H E C ‘ s arrangements for the symposium. VOL. 6 1
NO. 9
SEPTEMBER 1969
9
