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Potential flows: Computer graphic solutions
Computer Physics Communications North-Holland. Amsterdam
117
38 (1985) 117
BOOK REVIEW Potential Flows: Computer Graphic Solutions Robert
H. Kirchhoff,
Marcel Dekker
Inc., New York, 1985. xiv + 182 pages. US $45
The book consists almost entirely of plots of streamlines and isotachs (lines of constant speed) for potential flows, i.e. exact, irrotational, symmetric solutions of the incompressible, inviscid, Navier-Stokes equations. It comprises three chapters (plus an appendix that lists sample software), of which the first is by far the longest, containing plots of streamlines and isotachs for sixty-two different 2-dimensional flows. The second contains plots of eight 3-dimensional, i.e. axisymmetric, fluid motions. The last, which gives worked examples, probably gives away the nature of the most likely readership, namely engineering students whose courses take them across the various branches of fluid dynamics. As far as professionals are concerned, there is the usual difficulty that an aeronautics engineer is not likely to be keen to pay for pictures of canal flow, nor a hydraulicist for example of flows past aerofoils, and the book is not cheap. The figures themselves are very clearly produced and labelled, and it would seem to be a simple matter to interpolate from the diagrams in the manner suggested. The plotting of isotachs also makes it easy to calculate pressures using Bernouilli’s relation. The collection seems quite comprehensive in respect of kinds of flow: checking with Batchelor’s “An Introduction to Fluid Dynamics” I found only one flow not in Kirchhoff - the flat, circular disc moving normal to its plane. However, it is often likely to be the case that a flow is not plotted for the parameter one wants, e.g. Batchelor plots flow in the 135’ comer, whereas Kirchhoff confines himself to corner angles of 45O, 90”, 180°, 270” and 360”. In this case one is expected to write a program using the example programs in the appendix as a guide. However, Professor Kirchhoff is not a devotee of structured programming and the BASIC used is full of extensions, making this a difficult course. Nevertheless, the book should be useful for checking the accuracy of one’s code for one or two values of the parameters. It is helpful that analytic expressions for each of the flows are given, plus references to the standard texts from which they are taken. The supporting text appears to be free from typographical error, the one exception being the mispunctuation of “Reynolds’ number” throughout chapter 3: my only criticism is that a standard notation for the coordinates should have been employed throughout chapter 2. The quality of the type and its setting is however very poor, particularly when the price is taken into account. The text is not right-justified, but even so is often awkwardly split, and the mathematical symbols have come out fainter than the’rest. The layout could have been much improved, e.g. for much of the first chapter the text is half-a-page out of sync. with the plots. In summary, a useful text for engineering students with a hydrodynamical bias and money to spare, otherwise for libraries only. W. ARTER
OOlO-4655/85/$03.30 0 Elsevier Science Publishers (North-Holland Physics Publishing Division)
B.V.
117
38 (1985) 117
BOOK REVIEW Potential Flows: Computer Graphic Solutions Robert
H. Kirchhoff,
Marcel Dekker
Inc., New York, 1985. xiv + 182 pages. US $45
The book consists almost entirely of plots of streamlines and isotachs (lines of constant speed) for potential flows, i.e. exact, irrotational, symmetric solutions of the incompressible, inviscid, Navier-Stokes equations. It comprises three chapters (plus an appendix that lists sample software), of which the first is by far the longest, containing plots of streamlines and isotachs for sixty-two different 2-dimensional flows. The second contains plots of eight 3-dimensional, i.e. axisymmetric, fluid motions. The last, which gives worked examples, probably gives away the nature of the most likely readership, namely engineering students whose courses take them across the various branches of fluid dynamics. As far as professionals are concerned, there is the usual difficulty that an aeronautics engineer is not likely to be keen to pay for pictures of canal flow, nor a hydraulicist for example of flows past aerofoils, and the book is not cheap. The figures themselves are very clearly produced and labelled, and it would seem to be a simple matter to interpolate from the diagrams in the manner suggested. The plotting of isotachs also makes it easy to calculate pressures using Bernouilli’s relation. The collection seems quite comprehensive in respect of kinds of flow: checking with Batchelor’s “An Introduction to Fluid Dynamics” I found only one flow not in Kirchhoff - the flat, circular disc moving normal to its plane. However, it is often likely to be the case that a flow is not plotted for the parameter one wants, e.g. Batchelor plots flow in the 135’ comer, whereas Kirchhoff confines himself to corner angles of 45O, 90”, 180°, 270” and 360”. In this case one is expected to write a program using the example programs in the appendix as a guide. However, Professor Kirchhoff is not a devotee of structured programming and the BASIC used is full of extensions, making this a difficult course. Nevertheless, the book should be useful for checking the accuracy of one’s code for one or two values of the parameters. It is helpful that analytic expressions for each of the flows are given, plus references to the standard texts from which they are taken. The supporting text appears to be free from typographical error, the one exception being the mispunctuation of “Reynolds’ number” throughout chapter 3: my only criticism is that a standard notation for the coordinates should have been employed throughout chapter 2. The quality of the type and its setting is however very poor, particularly when the price is taken into account. The text is not right-justified, but even so is often awkwardly split, and the mathematical symbols have come out fainter than the’rest. The layout could have been much improved, e.g. for much of the first chapter the text is half-a-page out of sync. with the plots. In summary, a useful text for engineering students with a hydrodynamical bias and money to spare, otherwise for libraries only. W. ARTER
OOlO-4655/85/$03.30 0 Elsevier Science Publishers (North-Holland Physics Publishing Division)
B.V.