Review of Fundamentals of Open Channel Flow by Glenn E. Moglen

As the title suggests, this is a book on fundamentals of open channel flow. Since the publication of Chow’s classic book “Open-Channel Hydraulics” published in Chow (1959) and another classic book “Open Channel Flow” by Henderson published in Henderson (1966), a large number of books on open channel hydraulics have been published in the United States and abroad. The subject of open channel flow is as intriguing today as it was more than fifty years ago, largely because of its ubiquitous occurrence in nature and its fundamental importance in civil infrastructure design. As stated in the preface by the author, this book is narrower in scope than these two classic books but has unique and attractive features. This is one of the few books that are designed exclusively for the first course on open channel flow offered in the civil engineering undergraduate curriculum. The book will therefore be helpful to the instructor teaching the course. Because of this reason, the book will be equally helpful to the student preparing for the P.E. examination. The book has been written with the student in mind and for that reason the author has diligently tried to incorporate computer-based tools and graphical aids that the students of current generation have a penchant for, as well as include end-of-chapter problems.

The subject matter of the book is divided into seven chapters. The first chapter introduces the theme of the book and answers a number of basic questions that the student is often curious about. Defining and quantifying open channel flow, it lays the foundation for fundamental equations, and goes on to discussing classes of problems and the need for critical thinking. The chapter is concluded with a set of problems. It is a good introductory chapter. Energy is the topic of the second chapter that deals with both rectangular and nonrectangular channels. Beginning with a discussion of specific energy, it deals with the energy-depth diagram, critical flow; Froude number; alternate depths; energy considerations for upward and downward steps and channel constrictions and expansions; and chokes, critical flow and transients; changes in longitudinal flow. Then, the discussion moves to non-rectangular channels and includes energy, alternative depths, and critical depth. The chapter is concluded with a set of problems. This is a comprehensive and well written chapter. The third chapter is on momentum. It begins with introductory remarks and presents the momentum equation, hydraulic jump, energy and momentum losses, and momentum in non-rectangular channels. On the whole the chapter is well written and is highly informative.

Friction and uniform flow constitute the subject matter of the fourth chapter. Introducing the concept of friction, it first deals with uniform flow, shear stress in open channel flow, Chezy’s and Manning’s equations, uniform flow and normal depth, and reach classification. There are nine end-of-chapter problems. The chapter is very well written. Logically, gradually varied flow is presented in the fifth chapter. It discusses non-uniform flow, profile taxonomy, in-stream obstructions, composite profiles, drowned hydraulic jump, generalized upstream and downstream boundary conditions, and the concept of conjugate curve. The chapter is concluded with fifteen problems. The treatment in the chapter is quite comprehensive. Quantitative gradually varied flow is presented in the sixth chapter. Introducing the governing equation and its solution by the standard step method (SSM), the chapter discusses variations of and alternatives to the SSM, conjugative curve, and HEC-RAS. Eight end-of-chapter problems conclude the chapter. The chapter provides a comprehensive discussion.

The concluding chapter seven presents fundamentals of sediment transport. It first discusses the characterization of water and sediment, and then goes on to discussing Manning’s n as a function of channel and sediment characteristics, sediment motion, bed load and suspended sediment transport rate, sediment load estimation, and accuracy of sediment transport rate estimation. At the end of chapter there are nine problems. The book is concluded with an appendix tabulating circular channel properties.

Overall, this is an excellent book with a thorough treatment of open channel fundamentals. The book will be useful to the student who wants to understand open channels flow basics, and to the instructor who wants to teach the first undergraduate course in open channel hydraulics. Those who are outside of civil engineering profession but are interested in open channel flow will find the book to be a valuable resource.