Low Gravity Fluid Mechanics

This book presents the fundamentals of low gravity fluid dynamics and heat transfer. It investigates fluid behavior in low gravity environments such as those found in earth orbiting and space vehicles. The two major fluid phenomena affected by gravity (buoyancy and surface tension) are treated thoroughly from both the theoretical and applications points of view, and limitations of fluid and thermal responses to gravitational fields in space-based settings are clearly delineated. Summaries of all data available from low gravity flight and terrestrial experiments performed to date are also presented.

We are extremely grateful to Springer-Verlag and to Prof. Dr. W. BeiglbOck for bring ing out the English edition of our book. We are also thankful to Dr. R. S. Wadhwa for a qualified translation. While preparing the manuscript for translation, we took the opportunity to go through the whole text, make necessary amendments, supplement the original material with new results, and considerably enlarge the lists of references. We hope that this book will serv~ to strengthen the bonds of international coopera tion in this field. July 1986 The authors Translator's Note The final form of the bibliography contains a (free) English translation of all the Russian books and papers published in the USSR. This has been done at the request of the authors and with the concurrence of Prof. BeiglMck. The titles are not always exact, and some of the works have already been translated into English or other European languages. Unfortunately, the authors were not in a position to provide detailed information on this subject. R.S. Wadhwa Preface to the Russian Edition What shall I do ... With their weightlessness In this ponderous world? M. Tsvetaeva, The Poet This book deals with the behavior of a liquid in zero-gravity or conditions close to it. The surge of interest in zero-gravity problems stems from the progress attained in the field of spaceflight, where such conditions can be attained for long periods of time.

Electric propulsion systems for space vehicles must be able to restart and operate at zero and low gravity. This operation can be achieved if the tankage delivers only single-phase propellants. The requirements for feed systems of electric engines are described briefly. Also, the 1.85-second drop- test facility is described and the testing techniques are discussed. The minimum energy principle is presented along with a method for determining the direction of mass transfer in tapered tubes and liquid-vapor interface shapes in an annular space between concentric cylinders. Possible feed systems for electric engines are given, which utilize surface tension for fluid positioning and transfer. Zero-gravity and static-fluid configurations in cylindrical and spherical containers are discussed along with experimental observations. The interface 'overshoot' of the equilibrium zero-gravity configuration is also discussed.

Contents: Saturn V low-gravity fluid mechanics problems and their investigation by full-scale orbital experiment; An experimental investigation of the dynamic behavior of the liquid-vapor interface under adverse low- gravitational conditions; Inviscid fluid flow in an accelerating axisymmetric container; Some thermal aspects of a contained fluid in a reduced-gravity environment; Distribution of noncondensable gases in liquids under low-g conditions; The fluid mechanics of condensing mercury in a low-gravity environment; Dynamic response of liquids in partially-filled containers suddenly experiencing weightlessness; Low-gravity liquid reorientation; Interfacial stability of liquid layers on elastic surfaces; Sloshing of a liquid in a draining or filling tank under variable-g conditions; The effect of wall elasticity and surface tension on the forced oscillations of a liquid in a cylindrical container; Shape and stability of the liquid-gas interface in a rotating cylindrical tank at low g; Meniscus shape under reduced-gravity conditions; Liquid settling in large tanks; The Martin Company's low-g experimental facility; The application of hydrophilic and hydrophobic surfaces for phase separation in a low-g environment.

In a microgravity experiment, the conditions prevalent in fluid phases can be substantially different from those on the ground and can be exploited to improve different processes. Fluid physics research in microgravity is important for the advancement of all microgravity scients: life, material, and engineering. Space flight provides a unique laboratory that allows scientists to improve their understanding of the behaviour of fluids in low gravity, allowing the investigation of phenomena and processes normally masked by the effects of gravity and thus difficult to study on Earth. Physics of Fluids in Microgravity provides a clear view of recent research and progress in the different fields of fluid research in space. The topics presented include bubles and drops dynamics, Maragoni flows, diffustion and thermodiffusion, solidfication,a nd crystal growth. The results obtained so far are, in some cases, to be confirmed by extensive research activities on the International Space station, where basic and applied microgravity experimentation will take place in the years to come.

This careful selection of papers gives the reader an overview of the main research topics investigated at the conference and recent progress in understanding the physical phenomena involved. These lectures should therefore be a prime source of information for the expert as well as for graduate students. They cover critical point phenomena and adsorption, solidification, crystallization, static fluids and thermophysical properties, fluid dynamics and combustion. The importance of gravity as an experimental parameter and a variable in a large diversity of physical phenomena and processes has been recognized for some 25 years. The growth of this field of physics can be gleamed from the great number of satellites, sounding rockets, terrestrial trop towers, etc., that exist.