P L Kapitza enjoys well-deserved renown as one of the world's leading scientists. Since the first three volumes were published he has received many more honours, notably the Nobel Prize in Physics in 1979. This volume includes research papers, public talks and popular papers, and even an updated version of a book of problems providing a good indication of Professor Kapitza's wide range of interests.
The book introduces possibly the most compact, simple and physically understandable tool that can describe, explain, predict and design the widest set of phenomena in time-variant and nonlinear oscillations. The phenomena described include parametric resonances, combined resonances, instability of forced oscillations, synchronization, distributed parameter oscillation and flatter, parametric oscillation control, robustness of oscillations and many others. Although the realm of nonlinear oscillations is enormous, the book relies on the concept of minimum knowledge for maximum understanding. This unique tool is the method of stationarization, or one frequency approximation of parametric resonance problem analysis in linear time-variant dynamic systems. The book shows how this can explain periodic motion stability in stationary nonlinear dynamic systems, and reveals the link between the harmonic stationarization coefficients and describing functions. As such, the book speaks the language of control: transfer functions, frequency response, Nyquist plot, stability margins, etc. An understanding of the physics of stability loss is the basis for the design of new oscillation control methods for, several of which are presented in the book. These and all the other findings are illustrated by numerical examples, which can be easily reproduced by readers equipped with a basic simulation package like MATLAB with Simulink. The book offers a simple tool for all those travelling through the world of oscillations, helping them discover its hidden beauty. Researchers can use the method to uncover unknown aspects, and as a reference to compare it with other, for example, abstract mathematical means. Further, it provides engineers with a minimalistic but powerful instrument based on physically measurable variables to analyze and design oscillatory systems.
The unusual career of the famous Soviet physicist Peter Kapitza was divided between Cambridge and Moscow. In Cambridge he was a protegé of Rutherford and while studying there he opened up a new area of research in magnetism and low temperature physics. However, in 1934, during a summer visit to the Soviet Union, Kapitza was prevented from returning to Cambridge and remained in Moscow for the rest of his long life. In spite of many ups and downs and considerable difficulties in his relations with top political figures in the Kremlin, he continued to enhance his scientific reputation and late in life was awarded the Nobel Prize.After an introductory biographical memoir, the greater part of the book consists of extracts from the numerous letters Kapitza wrote throughout his life, letters which are distinguished by their eloquence, the originality of his opinions and his forthrightness. His very interesting correspondence with Rutherford and above all his many letters to top political figures in the Soviet Union such as Molotov, Stalin and Khrushchev on questions of scientific and industrial policy are all included in this unique document. Together they provide a rounded picture of a remarkable personality who contributed so much to the scientific and cultural life of both England and the Soviet Union.This fascinating book is illustrated with an impressive collection of historical photographs and should be of interest to science historians, to low temperature physicists and to `Sovietologists', but above all the book should appeal to the general reader for its human interest. Some of the letters reveal his emotional reactions to the major blows he had to suffer on several occasions, while others provide penetrating and often amusing comments on English life and institutions as seen by a Russian, and on Soviet life from the inside.
This work brings together previously unpublished notes contributed by participants of the IUTAM Symposium on Hamiltonian Dynamics, Vortex Structures, Turbulence (Moscow, 25-30 August 2006). The study of vortex motion is of great interest to fluid and gas dynamics: since all real flows are vortical in nature, applications of the vortex theory are extremely diverse, many of them (e.g. aircraft dynamics, atmospheric and ocean phenomena) being especially important.
The instability of fluid flows is a key topic in classical fluid mechanics because it has huge repercussions for applied disciplines such as chemical engineering, hydraulics, aeronautics, and geophysics. This modern introduction is written for any student, researcher, or practitioner working in the area, for whom an understanding of hydrodynamic instabilities is essential. Based on a decade's experience of teaching postgraduate students in fluid dynamics, this book brings the subject to life by emphasizing the physical mechanisms involved. The theory of dynamical systems provides the basic structure of the exposition, together with asymptotic methods. Wherever possible, Charru discusses the phenomena in terms of characteristic scales and dimensional analysis. The book includes numerous experimental studies, with references to videos and multimedia material, as well as over 150 exercises which introduce the reader to new problems.
for the fluctuations around the means but rather fluctuations, and appearing in the following incompressible system of equations: on any wall; at initial time, and are assumed known. This contribution arose from discussion with J. P. Guiraud on attempts to push forward our last co-signed paper (1986) and the main idea is to put a stochastic structure on fluctuations and to identify the large eddies with a part of the probability space. The Reynolds stresses are derived from a kind of Monte-Carlo process on equations for fluctuations. Those are themselves modelled against a technique, using the Guiraud and Zeytounian (1986). The scheme consists in a set of like equations, considered as random, because they mimic the large eddy fluctuations. The Reynolds stresses are got from stochastic averaging over a family of their solutions. Asymptotics underlies the scheme, but in a rather loose hidden way. We explain this in relation with homogenizati- localization processes (described within the §3. 4 ofChapter 3). Ofcourse the mathematical well posedness of the scheme is not known and the numerics would be formidable! Whether this attempt will inspire researchers in the field of highly complex turbulent flows is not foreseeable and we have hope that the idea will prove useful.
This highly acclaimed series provides survey articles on the present state and future direction of research in important branches of applied mechanics.
In December 1994 Professor Enok Palm celebrated his 70th birthday and retired after more than forty years of service at the University of Oslo. In view of his outstanding achievements as teacher and scientist a symposium entitled "Waves and Nonlinear Processes in Hydrodynamics" was held in his honour from the 17th to the 19th November 1994 in the locations of The Norwegian Academy of Science and Letters in Oslo. The topics of the symposium were chosen to cover Enok's broad range of scientific work, interests and accomplishments: Marine hydrodynamics, nonlinear wave theory, nonlinear stability, thermal convection and geophys ical fluid dynamics, starting with Enok's present activity, ending with the field where he began his career. This order was followed in the symposium program. The symposium had two opening lectures. The first looked back on the history of hydrodynamic research at the University of Oslo. The second focused on applications of hydrodynamics in the offshore industry today.
Marangoni (1878), provided a wealth of detailed information on the effects of variations of the potential energy of liquid surfaces and, in particular, flow arising from variations in temperature and surfactant composition. One aspect of this science is seen today to bear on important phenomena associated with the processing of modern materials. The role of the basic effect in technology was probably first demonstrated by chemical engineers in the field of liquid-liquid extraction. Indeed, phenomena attributable to Marangoni flows have been reported in innumerable instances relevant to modern technologies, such as in hot salt corrosion in aeroturbine blades; the drying of solvent-containing paints; the drying of silicon wafers used in electronics; in materials processing, particularly in metallic systems which have been suspected to demonstrate Marangoni flows.
