HANSEN W

GERMANY (see also List of Individuals)

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28.8.1832 Gotha/D - 14.10.1906 Gotha/D

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Wilhelm Hansen was a son of the famous astronomer Peter Andreas Hansen. He made studies in mathematics and physics at Göttingen University first and then moved to the Berlin University, where he graduated in 1854. He then went to an uncle in Rome and was involved in the telegraphic cable laying from the Suez Canal to Bombay. After having returned to his home city in 1861 he founded with a companion a small iron works which developed into Briegleb, Hansen & Co in Gotha. In the beginning, mainly gears and steam machines were fabricated: later, the company was mainly known as a turbine furnisher. Hansen realized that the computed turbine efficiencies were often inaccurate because of poor discharge measurement. This was the reason for Hansen's research into weir flow published in 1892. He was appointed in 1886 the title Geheimer Kommerzienrat, following Hansen's public service in his principality. He was also an early member of Verein Deutscher Ingenieure VDI and awarded honorary membership in 1902.

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Hansen conducted his weir research during an untimely period. In 1885, Henry Bazin (1829-1917) had initiated a large weir research at Canal de Bourgogne in Dijon. In total six papers plus a summary book resulted that included about all aspects of weir flow. In contrast, Hansen had not a real hydraulic background in his career but realized the need for more accurate discharge coefficients. The result of the 1892 study was an expression for the discharge coefficient involving a base value of 0.411, which reduces as the overflow height increases. The expression is dimensionally incorrect but remained popular in Germany until after World War I. Bazin's project was much more concerned with weir flow as a hydraulic problem and the emerging discharge coefficient was rather a side product of that outstanding research.

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_{Anonymous (1996). Hansen, Wilhelm. Deutsche biographische Enzyklopädie 4: 376. Saur: München.}

_{Hansen, W. (1892). Die Bestimmung von Wassermengen mittels Überfälle ohne Seitenkontraktion. Zeitschrift des Vereines Deutscher Ingenieure 36(37): 1057-1067; 36(38): 1087-1097.}

_{Rohrbach, A. (1906). Wilhelm Hansen. Zeitschrift des Vereines Deutscher Ingenieure 50(45): 1809-1810. P}

_{Tegtmeier, H. (1966). Hansen, Wilhelm Emil Leopold. Neue Deutsche Biographie 7: 631-632.}

_{Duncker&Humblot: Berlin.}