Introduction

This book deals with density, temperature, velocity and concentration fluctuations in fluids and fluid mixtures. The book first reviews thermal fluctuations in equilibrium fluids on the basis of fluctuating hydrodynamics. It then shows how the method of fluctuating hydrodynamics can be extended to deal with hydrodynamic fluctuations when the system is in a stationary nonequilibrium state.

Equilibrium vs. Nonequilibrium Fluctuations

In contrast to equilibrium fluids where the fluctuations are generally short ranged unless the system is close to a critical point, fluctuations in nonequilibrium fluids are always long-ranged encompassing the entire system. The book provides the first comprehensive treatment of fluctuations in fluids and fluid mixtures brought out of equilibrium by the imposition of a temperature and concentration gradient but that are still in a macroscopically quiescent state.

Boundary Conditions and Convection

By incorporating appropriate boundary conditions in the case of fluid layers, it is shown how fluctuating hydrodynamics affects the fluctuations close to the onset of convection.

Experimental Techniques

Experimental techniques of light scattering and shadowgraphy for measuring nonequilibrium fluctuations are elucidated and the experimental results thus far reported in the literature are reviewed.

Key Topics

Systematic exposition of fluctuating hydrodynamics and its applications

First book on nonequilibrium fluctuations in fluids

Fluctuating Boussinesq equations and nonequilibrium fluids

Fluid layers and onset of convection

Rayleigh scattering and Brillouin scattering in fluids

Shadowgraph technique for measuring fluctuations

Fluctuations near hydrodynamic instabilities