Fluid Dynamics with a Computational Perspective describes certain important aspects of fundamental fluid mechanics, using computational simulations to interpret the flow physics. The first two chapters deal with basic fluid dynamics and computational fluid dynamics (CFD); the next four chapters cover viscous incompressible flows of increasing Reynolds number, ranging from creeping flow to fully turbulent flow. The final two chapters deal respectively with compressible flow in gas dynamics and interface (free surface) flows. Rather oddly, in my opinion, potential flow is tucked away in the chapter on high Reynolds number flow and boundary layers!
The book commences by outlining the underlying framework of fluid properties, non-dimensional variables, and conservation laws. There is a nice build up of concepts, leading to an Eulerian description of fluid flow. Tensors are introduced in a clever and instructive way. Insightful illustrations are provided of certain important fluid phenomena, such as the pressure drop at a pipe bifurcation, and dissipation by friction in an oscillatory boundary layer. Comprehensive explanations are given of swirl, vapour trails, vorticity, circulation and lift. Useful tips are provided on how to visualise and hence interpret three-dimensional vortical flows. The second chapter examines CFD from a bird's eye perspective. It emphasises important aspects such as grid generation, accuracy, convergence, stability, dissipative and dispersive errors, multigrids and post-processing, without taking the reader into unnecessary detail regarding particular numerical methods. Useful comparisons are made between explicit and implicit methods, and coupled and decoupled treatments of the discretised equations. The emphasis is on finite-volume techniques. The section on grid generation considers structured and unstructured grids, but does not discuss hierarchical approaches for dynamic grid adaptation. The section on solution (in-)accuracy is essential reading for all CFD users.
Chapters 3 to 6 consider the effect of increasing Reynolds number on the flow dynamics, making use of computer simulations to enhance the reader's understanding. Low Reynolds number or creeping flows past various idealised obstacles are examined using analytical and numerical techniques, and the important concept of a resistance matrix is explained. Lubrication flows are also considered, reconciling the results from approximate analysis with the flow behaviour in real bearings. Chapter 4 covers vorticity, separation and wake development at intermediate Reynolds numbers. There is a most informative description of separation. The chapter presents results from various old favourite benchmark cases, such as laminar flow past a circular cylinder. Jets, wakes and mixing layers are treated using multidimensional scaling arguments, and the findings are compared against the results of numerical simulations. Chapter 5 introduces Prandtl's boundary layer concept, which divides the flow domain into a thin region near the body, including the wake where viscous effects are felt, and an inviscid potential flow region elsewhere. Flows of increasing complexity are investigated, highlighting boundary layer growth, separation and singular points such as saddles, nodes and foci. The authors nevertheless keep the descriptions as straightforward and understandable as possible — the aim being transparency. Section 5·6 considers potential flow, which makes sense as it relates to flow outside the viscous region, but I think should have merited a chapter in its own right as in other contexts (such as wave diffraction analysis) viscous effects are often entirely neglected and potential flow applied throughout the flow domain. Although Section 5·6 describes the use of point sources to represent a body in a potential flow, and the method of images, circulation, stream function and added mass, the flavour is predominantly analytical rather than involving simulation — unlike elsewhere in the book. Chapter 6 provides an authoritative summary of turbulent flow dynamics, in particular modelling approaches based on statistical averaging, the law-of-the-wall, direct numerical simulation, large eddy simulation and instability theory.
Compressible fluid dynamics is discussed in Chapter 7, which describes the basic thermodynamic principles, the analysis of shock and expansion waves, case studies (including supersonic flow past an obstacle, and flow in a convergent-divergent nozzle) and modern shock-capturing methods. Chapter 8 is dedicated to two-phase interface fluid dynamics, and examines interface conditions, surface tension, capillary and gravity waves, jet disintegration, sloshing and pouring of a viscous liquid. The latter cases highlight the impressive advances that have recently taken place in the simulation of three-dimensional violent free surface flows.
Overall the book is very readable. It is targetted at final year undergraduates and MSc students, and should be of considerable interest to CFD modellers, university academics and researchers. It is an interesting supplement to the existing literature on basic fluid mechanics. While on the whole, explanations are clear and precise, there are some statements used where the grammar could be improved (e.g. ‘At the root is the governing laws', which jars the English eye). The typesetting of the book is generally very professional, as one would expect of Cambridge University Press (CUP). There are some small anomalies, such as the decision to write as 1/2ρU2 throughout the text, making it less obvious to the less well-informed reader what should be the denominator (see also p. 82 where ‘fi=11/2,21/2,…' might have been better as ‘.'). On p. 81, the text ‘or φC0=2−φC1. φC0 is required' could have been better laid out, as some readers might confuse the full stop with a multiplication! The figures are well set out, although it would have perhaps been worthwhile if CUP had used contours rather than black-and-white contrast in certain cases (e.g. Figure 1.2 on p. 16, where one needs to have quite a powerful light focused on the page to see the slightly non-vertical pressure contours in the curved contraction).
In short, the book brings considerable insight into the wonderful and paradoxical world of fluid mechanics. I am happy to recommend it to researchers, academics and practitioners interested in applying or developing CFD software.
