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Crane - Flow of Fluids Through Valves, Fittings and Pipe (1)For 70 years the Crane Handbook has been the most widely used guide for calculating pressure losses in piping systems assembled from fittings and schedule pipe. The guide contains a limited range of loss coefficients and these relate to commercial fittings. Flow passages in commercial fittings vary between manufactures, between fitting bore sizes and for different pressure ratings. Tolerances on pipe bores can give a spread of over 20% in pressure losses. Calculated pressure losses in small systems made up of commercial fittings are rough estimates and the limited range of indicative loss coefficients in the Handbook suffices. Over the years the Handbook has been revised and substantial amounts of information on fluid properties and other fluid related information added. However, the Handbook shows its age as it mainly draws on references that are over 50 years old. Engineers familiar with the Crane Handbook will naturally continue to use it but it is not sensible for engineers with a need to become proficient in designing and analysing flow systems to adopt the Crane Handbook.
Idelchik - Handbook of Hydraulic Resistance (2) At the time I was writing Internal Flow Systems an English translation of the 1st edition of Idelchik's handbook was available, but it contained so much unreliable data that it was not appropriate to use it a reference. In essence the 1st edition was a compilation of mainly Russian experimental work, with little regard to its accuracy or suitability, Before his death in 1990 Idelchik had completed the enormous task of discarding much of the unreliable experimental data in the 1st edition. The English 3rd edition of the Handbook is much improved over the 1st. The content has been expanded and includes numerous references from Western sources, although data from these sources is not used extensively in the text. Idelchik took the view that “loss coefficients from less vigorous experimental investigations and those predicted or obtained by approximate calculations based on separate experimental studies” would be included in the Handbook. Unfortunately, it is not clear in the text which loss coefficients are reliable and which are doubtful. Idelchik’s own experimental work was of a high quality and loss coefficient data from his published papers are included in IFS. His extensive background in experimental fluid dynamics is reflected in the quality and extensive explanations and recommendations included in the Handbook. This is not a user friendly Handbook. The shear volume of its content is daunting, much of the content is only relevant to a very small audience and the user is left with the task of assessing the reliability of the loss coefficients. However, anyone with an unusual internal flow situation is likely to find some relevant information.
Miller - Internal Flow Systems (3)With Internal Flow Systems I have tried to achieve a user-friendly handbook that provides reliable data and information. The core loss coefficient data in is classed as definitive. These definitive loss coefficients relate to components of known geometry at a Reynolds number of a 10E6 installed with specified inlet and outlet pipe or passage arrangements. Corrections are provided for other Reynolds numbers and inlet and outlet arrangements. The definitive loss coefficients have their origins in extensive experimental work carried out at BHRA at Reynolds numbers of a million. The BHRA experimental coefficients were verified and extended using experimental results from individuals and groups in universities and research institutions who were active for an extended period of time. Definitive loss coefficients provide reference points for researchers seeking to add to our knowledge on internal flow. Starting with component geometries for which definitive loss coefficients are available, researchers can validate their experimental equipment and techniques. They can then establish correction factors that account for departures from defined geometric and installation conditions. Although Internal Flow Systems is almost 30 years old its penetration into industry is modest. This reflects the slow diffusion of new practices into industry, which can take more than one generation of engineers and designers to make a significant impact. Where Internal Flow Systems has been adopted by an industry, such as the automobile industry, it has been through the Flowmaster suite of computer programs. Commercial pressures both promote and cause an industry to adopt powerful analysis and design software, which in the case of Flowmaster has much of the content of Internal Flow Systems embedded in its core.
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