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These reviews of books and other forms of information express the opinions of the individual reviewers and are not necessarily endorsed by the Editorial Board of this Journal. pp. Price: $74.95 hardback and $30.95 paperback.The area of acoustics concerned with nonlinear wave propagation is traditionally called nonlinear acoustics. Several books on this subject are available ͓Zarembo and Krasil'nikov ͑1966͒, Beyer ͑1974͒, Rudenko and Soluyan ͑1975͒, Hamilton and Blackstock ͑1998͔͒. The book by Naugolnykh and Ostrovsky provides yet another perspective on nonlinear acoustics, and it is written by two leading experts who have worked in this field for almost 40 years. Perhaps the more novel feature of their book, which is reflected in the title, is that nonlinear acoustics is considered as a branch of nonlinear wave physics. Such an approach appears to be very fruitful, as it permits the application to acoustics of many concepts and results obtained in other areas of nonlinear wave physics ͑e.g., nonlinear optics͒.The book consists of seven chapters. Chapter 1, entitled ''Nonlinearity, dissipation and dispersion in acoustics,'' describes several models illustrating the combined effects of these three phenomena on acoustic waves in various media. Westervelt, simple-wave, and Burgers equations are developed for nonlinear propagation in gases, liquids, and isotropic solids. Besides these results ͑which can be found in all books on nonlinear acoustics͒, the authors consider media with internal structure having dimensions small compared with a wavelength, such as liquids with gas bubbles and isotropic solids with empty spherical cavities. It is shown how these microinhomogeneities introduce not only additional losses, but also dispersion and a substantial increase in nonlinearity. The chapter concludes with discussion of ''anomalous'' nonlinearities in elastic solids, which are modeled with stress-strain relations not described by a simple power law. Such nonlinearities are associated with dislocations, grains, and microcracks in the medium. Recent developments in this area are very interesting, and it is unfortunate that only a brief survey of these results is presented.In Chapter 2, entitled ''Simple waves and shocks in acoustics,'' evolution of nonlinear plane waves is considered when effects of dissipation and dispersion are much weaker than that of nonlinearity. In this case, initially smooth acoustic perturbations transform eventually to weak shock waves. The chapter presents classical results for shock formation and describes the corresponding evolution of the frequency spectrum within the framework of the simple-wave and Burgers equations. Results for propagation of intense noise are also presented. In our opinion, the most interesting part of this chapter is Section 6, where propagation in media with anomalous nonlinearity is considered. Models are presented for media with two different stress-strain relations. The first, based on a modified Burgers equation, describes propagation in cubically nonlinear media. ...

A time-domain algorithm that solves the Khokhlov–Zabolotskaya–Kuznetsov (KZK) nonlinear parabolic wave equation is described. The algorithm models the propagation of pulsed finite amplitude sound beams radiated from axisymmetric sources in homogeneous, thermoviscous fluids. Numerical results are presented for waveform distortion and shock formation in directive beams radiated by pulsed circular pistons. Waveforms are calculated through the shock region and out to far-field locations where they are dominated by the nonlinearly generated low-frequency components. Effects of pulse duration, frequency modulation, and noise are examined. Methods for including relaxation and focusing are described.

An analytic solution is derived for acoustic streaming generated by a standing wave in a viscous fluid that occupies a two-dimensional channel of arbitrary width. The main restriction is that the boundary layer thickness is a small fraction of the acoustic wavelength. Both the outer, Rayleigh streaming vortices and the inner, boundary layer vortices are accurately described. For wide channels and outside the boundary layer, the solution is in agreement with results obtained by others for Rayleigh streaming. As channel width is reduced, the inner vortices increase in size relative to the Rayleigh vortices. For channel widths less than about 10 times the boundary layer thickness, the Rayleigh vortices disappear and only the inner vortices exist. The obtained solution is compared with those derived by Rayleigh, Westervelt, Nyborg, and Zarembo.

A formulation of the elastic energy density for an isotropic medium is presented that permits separation of effects due to compressibility and shear deformation. The motivation is to obtain an expansion of the energy density for soft elastic media in which the elastic constants accounting for shear effects are of comparable order. The expansion is carried out to fourth order to ensure that nonlinear effects in shear waves are taken into account. The result is E≃E0(ρ)+μI2+13AI3+DI22, where ρ is density, I2 and I3 are the second- and third-order Lagrangian strain invariants used by Landau and Lifshitz, μ is the shear modulus, A is one of the third-order elastic constants introduced by Landau and Lifshitz, and D is a new fourth-order elastic constant. For processes involving mainly compressibility E≃E0(ρ), and for processes involving mainly shear deformation E≃μI2+13AI3+DI22.