The close interplay between theoretical, experimental and computational approaches in fluid mechanics has always been essential for the advancement of this subject area. Historically, the perception about the importance of one approach over another has fluctuated. In the 1980s, some predicted that the need for experimentation would disappear because of significant advancements in computational fluid dynamics and spectacular growth in computing power. However, these predictions have not been realised; in fact modern experimental fluid mechanics is experiencing accelerated development with the emergence of new measurement capabilities of unprecedented spatial and temporal resolution. In this regard it is worth quoting the prominent turbulence theoretician A. Tsinober: ‘There seems to be no way to replace experiments in turbulence in the foreseeable future and even beyond: nobody will believe in theoretical predictions only.' (Tsinober, 2009).
Surprisingly, however, the number of books on theoretical and numerical approaches in fluid mechanics substantially exceeds the number of books addressing experimental techniques. Fortunately, the available ‘experimental' books, although small in number, are of high quality and serve experimentalists very well. Tavoularis' Measurement in Fluid Mechanics is one of them. It nicely complements another excellent book edited by Goldstein (1996), continuing the solid traditions established by Bradshaw (1971).
Tavoularis' book consists of two main sections. The first section is entitled ‘General concepts' and contains seven chapters covering basic flow principles, measuring systems, measurement uncertainty, signal conditioning and discretisation, fundamentals of optical measurement, experimental facilities and experimental design. The emphasis here is on basic principles, encouraging the reader to understand the key processes involved in producing a final measurement. The sections on static and dynamic response of measuring systems, measurement errors and uncertainty, and signal processing and analysis should be compulsory reading for all experimentalists, not just fluid mechanicians. The chapter on optical measurement is the longest of this first section and covers fundamental properties of light and principles of emission and propagation, followed by a comprehensive account of various optical-based instrumentation and the characteristics and dynamics of seeding materials.
The second section of the book is entitled ‘Measurement techniques' and contains another seven chapters covering measurement of flow pressure, flow rate, flow visualisation, local flow velocity, temperature, components of fluid mixture (e.g. products of combustion and chemical reactions, suspended solid and liquid particles) and wall shear stress. The approach is to present a classification of the various methods used to measure the particular flow parameter, followed by an account of particular techniques. So, for example, methods for measuring local flow velocity are classified as pressure difference, thermal, frequency-shift, marker-tracing and mechanical, and the chapter details most of these methods, again with emphasis on basic principles. Inevitably, some techniques are more thoroughly covered than others; for example, the presentation of laser Doppler velocimetry is detailed while ultrasonic Doppler velocimetry is only briefly discussed. From the perspective of the present reviewers, the inclusion of measurement methods for surface and internal waves, sediment motion and flow–biota interactions would be welcome additions to a future edition of the book.
The book is very well written and illustrated throughout. It is suitable for undergraduates, but will be particularly useful for postgraduate students working on experimental topics. All chapters come with comprehensive reference lists, as well as questions and problems geared to testing understanding of the material covered. Although not as comprehensive as Goldstein (1996), which is exactly two times thicker, Tavoularis' Measurement in Fluid Mechanics provides an excellent reference source for the fundamental knowledge needed for good experiments – knowledge that unfortunately is too often glossed over by the rushed or careless experimenter. It also provides an excellent introduction to most of the measurement techniques used in modern practice. Representing very good value for money, Tavoularis' book is to be highly recommended to all with an interest in fluid mechanics experiments and measurements.
