The present volume entitled "Perspectives in Turbulence Stud ies" is dedicated to Dr. Ing. E. h. Julius C. Rotta in honour of his 75th birthday. J. C. Rotta, born on January 1, 1912, started his outstanding career in an unusual way, namely in a drawing office (1928 - 1931). At the same time he - as a purely self taught perso- took a correspondence course in airplane construction. From 1934 to 1945 he worked in the aircraft industry on different subjects in the fields of flight mechanics, structures, air craft design, and aerodynamics. In 1945 he moved to Gottingen and worked from that time at the Aerodynamische Versuchsanstalt (AVA, now DFVLR) and the Max-Planck-Institut fur Stromungsforschung (1947-1958), interrupted only by a stay in the U. S. at the Glenn L. Martin Company (1954 - 1955) and a visiting professorship at the Laval University in Quebec, Canada (1956). Already during his activities in industry, Dr. Rotta discovered his special liking for aerodynamics. In Gottingen, he was attracted by Ludwig Prandtl's discussions about problems associated with turbulence and in particular his new contribution to fully developed turbulence, published in 1945. At that time, W. Heisenberg and C. F. v. Weizacker pub lished their results on the energy spectra of isotropic turbu lence at large wave numbers. Since that time his main research interest in reasearch has been in turbulence problems.

This book contains contributions by former students, colleagues and friends of Professor John L. Lumley, on the occasion of his 60th birthday, in recognition of his enormous impact on the advancement of turbulence research. A variety of experimental, computational and theoretical topics, including turbulence modeling, direct numerical simulations, compressible turbulence, turbulent shear flows, coherent structures and the Proper Orthogonal Decomposition are contained herein. The diversity and scope of these contributions are further acknowledgment of John Lumley's wide ranging influence in the field of turbulence. The large number of contributions by the authors, many of whom were participants in The Lumley Symposium: Recent Developments in Turbulence (held at ICASE, NASA Langley Research Center on November 12 & 13, 1990), has presented us with the unique opportu nity to select a few numerical and theoretical papers for inclusion in the journal Theoretical and Computational Fluid Dynamics for which Professor Lumley serves as Editor. Extended Abstracts of these pa pers are included in this volume and are appropriately marked. The special issue of TCFD will appear this year and will serve as an additional tribute to John Lumley. As is usually the case, the efforts of others have significantly eased our tasks. We would like to express our deep appreciation to Drs. R.

Paperback edition of text on fluid dynamics for graduate students and specialists alike.

Beginning with a description of turbulence, its various manifestations, and a brief history of study, this text also incorporates modern perspectives on turbulence. The text also covers such topics as intermittency and the resultant conditional sampling and averaging of turbulent flows, the role of large scale computation of the fundamental equations of fluid mechanics in providing information on variables, and asymptotic methods which are used to expose important features of turbulent flows. Meaningful exercises are included in every section.