This book contains the proceedings of an IUTAM Symposium on turbulent flows at low Mach number, in which fluctuations in density occur as a result of heat transfer or of mixing of different fluids. Such flows occur in the atmosphere, the ocean, and in chemical engineering. In addition, in combustion large fluctuations in density occur as a result of heat release; the flows that are considered here do not involve heat release, for the most part, but the variable density flows that are considered can serve as a paradigm for many of the problems that arise in combustion as a result of the density fluctuations. Compressible flows - such as supersonic ones - are also considered in order to underline their similarities to and their differences from low-speed variable density flows. The book will be of interest to mechanical, aerospace, civil, and chemical engineers, meteorologists and oceanographers - in fact, anyone who deals with fluids in which fluctuations of density occur. The book will be accessible to professional and graduate students. There are no other works that deal with this interesting area.

In various industrial applications, turbulence can be affected by density variations resulting from different origins acting simultaneously. This monograph is intended as a first attempt to address variable density fluid turbulence in a unifying manner. It is based on a rational approach, developed along a gradual analysis of the complexity resulting from density fluctuations in turbulence.
The first part aims at providing the physical and theoretical framework of the analysis of density variations in fully turbulent flows. Its scope is deliberately educational.
In the second part, basic data on dynamical and scalar properties of variable density turbulent flows are presented and discussed, based on experimental data and/or results from direct numerical simulations. This part is rather concerned with a research audience.
The last part is more directly devoted to an engineering audience and deals with prediction methods for turbulent flows of variable density fluid. Both first and second order, single point modeling are discussed, with special emphasis on the capability to include specific variable density / compressibility effects.
The main topics are:

-Physical aspects of variable density turbulent flows,
-General equations and Classification of variable density turbulent flows,
-Statistical averaging in variable density fluids motions,
-Velocity and scalar structure in passive contaminant turbulence,
-Basic Mechanisms in low speed variable denisty turbulence,
-The high speed free shear layer and Single point closure in variable density fluid turbulence. The book is intended for a rather wide audience, including postgraduate students, researchers and engineers. Variable Density Fluid Turbulence should be of interest to various domains of Mechanics, Energy and Environmental Fluid Dynamics, such as Aerodynamics, Turbulence, Compressible flows, Heat and Mass Transfer, Machinery Fluid Mechanics, Thermal sciences

The first part aims at providing the physical and theoretical framework of the analysis of density variations in fully turbulent flows. Its scope is deliberately educational.
In the second part, basic data on dynamical and scalar properties of variable density turbulent flows are presented and discussed, based on experimental data and/or results from direct numerical simulations. This part is rather concerned with a research audience.
The last part is more directly devoted to an engineering audience and deals with prediction methods for turbulent flows of variable density fluid. Both first and second order, single point modeling are discussed, with special emphasis on the capability to include specific variable density / compressibility effects.

This didactic book presents the main elements of acoustics, aeroacoustics and vibrations. Illustrated with numerous concrete examples linked to solid and fluid continua, Acoustics, Aeroacoustics and Vibrations proposes a selection of applications encountered in the three fields, whether in room acoustics, transport, energy production systems or environmental problems. Theoretical approaches enable us to analyze the different processes in play. Typical results, mostly from numerical simulations, are used to illustrate the main phenomena (fluid acoustics, radiation, diffraction, vibroacoustics, etc.).