GIRARD L D

FRANCE (see also List of Individuals)

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.. 1815 /F - 28.5.1871 Seine River/F

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Louis-Dominique Girard was an autodidact. In his 1855 Note he realized the potential of fluvial hydropower. However, the turbines of then had disadvantages, such as small rotational speed, and an efficiency of only 20% without any mechanism to adapt production to a variable hydraulic head. Based on a prototype machine, Girard outlined a novel design: A mobile wheel attached to a vertical axis with "teeth" along its perimeter transmits the hydraulic energy to the nearby factory. The wheel is made of two concentric crowns composed of a cut-off ring from the top to the bottom. On the latter curved paddles are attached. The top paddles are stronger curved than those close to the bottom, and its diameter increases in the streamwise direction to reduce the water velocity at the turbine outlet thereby increasing the turbine efficiency. The second fixed part of the turbine looks like a vertical pipe mounted around the turbine axis, and conveys the water to the various paddles. The third also fixed turbine element is a conical roll and keeps the lower pivot. In 1857 Girard patented that so-called helical wheel turbine. Girard was hit by a bullet from a German enemy during the Franco-Prussian War which caused his premature death.

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Girard turbines worked normally unsubmerged, they had to be set at a level sufficiently high above the tailwater, therefore. Originally, his turbines had no draft tube to increase turbine efficiency. Only later, Girard realized this improvement of the "siphon turbine". He designed one machine with a hydraulic head of 180 m used for the compressed air supply during the tunneling of Gotthard in Switzerland in the 1870s. Girard invented also the "hydraulic railroad" gliding on skates: The train received speed by pressurized water ejected from distributors along the rail. Patented in 1853, that train was first presented in 1869 and was an attraction during the 1889 World Exposition in Paris.

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_{Alphandéry, M.-F. (1962). Girard. Dictionnaire des inventeurs français: 161-162. Seghers: Paris. Anonymous (1872). Girard. Jahrbuch der Erfindungen 8: 387.}

_{Anonymous (1881). Girard-Turbine im Stauwasser. Maschinen-Constructeur 14: 8-11.}

_{Girard, L.-D. (1855). Nouveau récepteur hydraulique, dit roue-hélice à axe horizontal, ou turbine sans directrices. Comptes Rendus de l'Académie des Sciences, Paris 40: 1025-1028. Girard, L.-D. (1863). Utilisation de la force vive de l'eau appliquée à l'industrie. Mallet: Paris.}

_{Meissner, L. (1967). 100 Jahre Voith Wasserturbinen. Voith-Forschung 15(1): 1-15.}

_{Payen, J. (1975). Girard, Louis-Dominique. Scienziati e tecnologi 2: 17. Mondadori: Milano. Suyreff, P. (1889). Girard, inventeur du chemin de fer glissant. Le Monde Illustré (2): 197-199. P}