COKER

UNITED KINGDOM (see also List of Individuals)

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26.4.1869 Wolverton/UK - 9.4.1946 Ayr/UK

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Ernest George Coker made his studies at the Royal College of Science, London and took the B.Sc. from Edinburgh University. He graduated as mechanical engineer at Cambridge University. In 1898 he began as a university teacher at the McGill University in Canada. He there worked on hydraulic problems connected to various power schemes. He returned to England as a professor of mechanical engineering at the City and Guilds Technical College of Finsbury from 1905. There he worked for the following nine years on the subject to which he devoted the rest of his life, and with which his name is connected. He explored the stresses in engineering components and structures by using the stressoptical effect. The first paper entitled The optical determination of stress was published in the Philosophical Magazine in 1910. In 1911, a second paper followed in the Transactions of the Naval Architects and his first paper in the Royal Society was published in 1912. Coker was appointed in 1914 to the Kennedy Chair of Civil and Mechanical Engineering at University College, London, and there developed "photoelasticity", of which a treatise resulted with a colleague in 1931.

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Coker is known in hydraulics for works published during his early career. The 1903 paper relates to the effect of temperature on the transition of laminar to turbulent pipe flow. Once Osborne Reynolds (1842-1912) had published his path-breaking 1883 paper on the two regimes in pipe flow, and postulated that this phenomenon is only affected by the current Reynolds number, Coker made a detailed experimental analysis to verify the concept. The second paper published in 1904 is a similar attempt to demonstrate Reynolds' criterion, which is actually used as an index for viscous effects in hydraulics.

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_{Anonymous (1946). Prof. E.G. Coker. The Engineer 181: 365.}

_{Anonymous (1952). Coker, Ernest George. Who was who 1941-1950: 233-234. Black: London.}

_{Barnes, H.T., Coker, E.G. (1904). The flow of water through pipes - Experiments on streamline motion and the measurement of critical velocity. Proc. Royal Society 74: 341-356.}

_{Coker, E.G., Clement, S.B. (1903). An experimental determination of the variation with temperature of the critical velocity of flow of water in pipes. Phil. Trans. A 201: 45-61.}

_{Coker, E.G. (1924). Some engineering problems of stress. 1 IUTAM Congress Delft: 18-38. Hill, G.T.R. (1946). Prof. E.G. Coker, F.R.S. Nature 157: 722.}

_{Jessop, H.T. (1952). Ernest George Coker. Notices on Fellows of the Royal Society 8: 389-393. P}

_{Poggendorff, J.C. (1925). Coker, Ernest George. Biographisch-Literarisches Handwörterbuch}

_{5: 234; 6: 463-464; 7b: 866. Verlag Chemie: Leipzig, with bibliography.}