Review of Turbulence in Coastal and Civil Engineering by B. Mutlu Sumer and David R. Fuhrman

This book is published as part of the Advanced Series on Ocean Engineering (World Scientific, Vol. 51). The principal aim of the book is “to describe in detail turbulent flow processes in coastal and civil engineering.” The considerable experience and knowledge of the authors are reflected throughout the book; containing ten chapters that are informatively divided into sections and subsections, the last section contains an extensive reference list. Most of the chapters also include valuable appendixes, several of which are divided into sections elaborating specific topics. Examples are also provided in most of the chapters. Each of the chapters is briefly described in the following paragraphs.

Chapter 1, “Introduction and the origin of turbulence,” consists of eight sections. Following a brief introduction referring to the pioneering experiments by Osborne Reynolds, the nature of turbulence is demonstrated with examples of turbulent flow, which in turn are elaborated later in the book. These are “flow over a flat plate,” “flow in wave boundary layers,” “flow in wave boundary layers in solitary motion,” “steady and oscillatory flow in pipes,” “flow around a circular cylinder in steady current,” and “flow induced by breaking waves.” In the appendix further details on the transition process to turbulence over a flat plate are discussed, the hydrodynamic stability theory for flow over a flat plate is given, and a summary of recent results of direct numerical simulation (DNS) of transition to turbulence for zero-pressure-gradient, smooth flat-plate boundary layer flow. Overall, the first chapter provides the reader with glimpses of the topics dealt with in further detail later in the book. By including a detailed discussion of the transition process in the canonical flat-plate case, this reviewer believes the book “will help the reader get a good feel of the transition process in the general study of turbulence” (p. 4). In particular, the discussion of turbulent spots that includes schematic representations will help the reader understand the transition process.

Chapter 2, “Basic equations for turbulent flows,” contains four sections. The first section describes the method of averaging and Reynolds decomposition, followed by applying this to the continuity equation, the equations of motion, and the energy equations. The continuity and Navier–Stokes equations are derived in the appendix.

Chapter 3, “Steady turbulent boundary layer flows,” consists of six sections. The first section deals with flow close to a wall by first presenting a general analysis followed by provision of the mean and turbulence characteristics of flow close to a smooth and a rough wall. The next section discusses the flow across the entire channel/pipe section. Section 3 deals with the turbulence modeling approach close to a wall and across the entire channel/pipe section. The next section discusses flow resistance by referring to the flow in a smooth, rough, and transitional circular pipe, as well as in a noncircular pipe and an open channel. A major part of this chapter is devoted to the bursting process (Section 5) and to the implications of the bursting process for sediment transport (Section 6). Here the focus is on considering the process as a quasi-cyclic process as opposed to the classical approach of viewing it as a stochastic process. The appendix deals with dimensional analysis, presenting Buckingham’s Pi theorem, exemplifying how this is applied to deducing the law of the wall.

Chapter 4, “Statistical, correlation and spectral analysis,” contains three sections, each dealing with one of the three topics given in the heading of the chapter. An appendix provides details of proofs of some common isotropic turbulence relationships. The focus of this chapter is analysis, which is emphasized by supplementing the text with five practical MATLAB examples that can be downloaded. This also makes it possible for the reader to modify and adapt the codes to their own needs. Overall, this chapter relates closely to physical examples supporting understanding of the concepts involved in this kind of analysis.

The next three chapters take up half the book, reflecting the authors’ and their research groups' substantial contribution to research on turbulent flows in coastal and civil engineering.

Chapter 5, “Wave boundary layers,” consists of twelve sections, starting with a discussion of laminar wave boundary layers. Section 2 is devoted to laminar-to-turbulent transition including a description and discussion of turbulent spots and their role in understanding the transition process. This is visualized by showing results from experiments and numerical simulations, helping the reader to understand the transition process in wave boundary layers. The next two sections discuss turbulent wave boundary layers over smooth and rough beds, respectively. Section 5 deals with flow resistance in wave boundary layers; the next section considers the combined wave and current boundary layers in the light of experiments conducted in an oscillating water tunnel. Section 7 covers boundary layers in wave flumes for waves alone and for combined waves and current. The next section is devoted to the bursting process in wave boundary layers, followed by a section on miscellaneous wave boundary layer examples. Sections 10 and 11 deal with solitary and tsunami wave boundary layers, respectively. The final section in this chapter is devoted to mathematical modeling of turbulent wave boundary layers, including reference to a MATLAB code for solving the two-equation k–ω closure, which is further applied in Chapter 10. The appendix gives particular essentials of linear potential flow theory by reviewing some basic concepts and fundamental aspects.

Chapter 6, “Streaming in wave boundary layers,” contains six sections on streaming, four of which are beneath sinusoidal progressive waves; in diverging-converging oscillatory flow; due to changing bottom roughness; and beneath nonsinusoidal waves. The two last sections provide examples of streaming beneath real waves and the importance of streaming and wave shape in coastal sediment transport, respectively. The vorticity equation is derived in the appendix together with demonstrating vorticity generation due to anisotropic normal Reynolds stresses.

Chapter 7, “Flow and turbulence in breaking waves,” has six sections. The first deals with breaking waves and breaker types. The next four sections are devoted to flow induced by spilling, plunging, surging, and plunging solitary waves, respectively. Here references are made to experiments containing discussions of the bed shear stress and mechanisms of sediment suspension beneath plunging and surging breaking waves. The last section deals with the numerical simulation of breaking waves, including stability analysis and simulations of spilling and plunging breaking waves and comparison with experimental results. The depth-integrated momentum equation is derived in the appendix.

Chapter 8, “Diffusion and dispersion,” consists of seven sections: the first two deal with one-particle analysis and conservation of mass: Eulerian analysis, respectively. The next four sections discuss longitudinal dispersion in general, longitudinal dispersion in an open channel, longitudinal dispersion in rivers, and longitudinal dispersion in an oscillating tunnel. The last section deals with dispersion in the surf zone. An appendix considers the calculation of settling velocity.

Chapter 9, “Mathematical modeling of turbulence,” contains six sections in which the first two address the closure problem and types of turbulence models. The next three sections provide Prandtl’s mixing length model, Wilcox’s k–ω model, and the large eddy simulation (LES). The last section discusses the scaling of computational costs in simulations of turbulent flow related to DNS, LES, and turbulence energy equation models. The exact k equation is derived in the appendix.

Chapter 10, “Hands-on exercises,” contains seven sections. The first three sections include an introduction followed by describing three actual data sets from laboratory measurements used as part of the exercises, and a description of the provided MATLAB-based k–ω turbulence closure model. The next four sections each provide an exercise: analysis of a turbulent boundary layer in an open channel; a simple numerical model of dispersion in a turbulent boundary layer flow; statistical, correlation and spectral analysis of turbulent air jet flow; and turbulence modeling of oscillatory wave boundary layer flows. This enables the reader to gain unique “hands-on” experience in the analysis of data from measurements and in the modeling of turbulence, including comparison with measurements related to the material dealt with in previous chapters.

Although the authors draw attention to some of the remaining research issues and knowledge gaps in our understanding of the turbulent flow process in coastal and civil engineering, it would have been of great value to the readers to have a final chapter that points out where present knowledge is incomplete and more research is needed.

In summary, this reviewer feels that the principal aim quoted earlier is achieved by the authors. The text has a good balance between the physics and the mathematics involved. This is obtained by introducing the physical phenomena and concepts using examples, schematic representations, and conceptual sketches, supplemented with basic and more advanced theory, as well as results from both experiments and numerical simulations. The authors have certainly produced a well-written, carefully organized, and informative book. The book is well suited to teaching graduate and post graduate students as well as for professionals and researchers working in the field of coastal and civil engineering. This reviewer also concurs with the authors’ assertion, “While this book is directed toward coastal and civil engineers, the contents will likewise provide sufficient background in the study of turbulent flows to also be relevant to many other disciplines, such as those related to wind, mechanical, environmental and chemical engineering” (p. 2). Although the title contains the word “engineering,” the book should also be highly relevant to those working in related fields such as marine geology and oceanography. It is believed that the book will play an important role as a source of information and learning, and that it will become a standard text on turbulence in the area of coastal and civil engineering as well as in related disciplines for years to come. It is on this basis that I highly recommend the book.