ABSTRACT
LENZ 22.09. 1906 Fond du Lac WI/USA 08.08. 1992 Madison WI/USA Arno Thomas Lenz was educated at University of Wisconsin, Madison WI, from where he graduated with a BSc in 1928, the MSc in civil engineering in 1930, and the PhD in 1940. He there continued as an instructor in hydraulics and sanitary engineering until 1937, assistant professor in these fields there until 1943, associate professor until 1948, from when he was there a professor of civil engineering. He in parallel directed from 1950 the hydraulic laboratory of University of Wisconsin. He also was an official TVA witness of the Wheeler Turbine Acceptance Test in 1935, prepared the Wisconsin Water Plan Report for the National Resources Commission in 1936, and was in charge of hydraulic model tests for the Petenwell Dubay Dams, Wisconsin. Lenz was a member of the American Society of Civil Engineers ASCE, the American Geophysical Union AGU, the American Meteorological Society AMS, and the American Water Works Association. Lenz was particularly known for his 1943 paper, presenting one of the most systematic approaches to scale effects in hydraulic engineering. He considered the triangular notch weir and determined its discharge coefficient for a large number of fluids, in which both viscosity and surface tension were varied by the addition of chemicals, or by changing temperatures of oils. The final proposal was also compared with the many existing data. Limitations in terms of minimum Reynolds and Weber numbers were stated, above which the conventional weir equation may be applied. The high alkalinity of rivers in Wisconsin inspired the authors of the 1944 paper to establish a relationship between alkalinity and river discharge and to use this for discharge determination by a natural dilution method. The professional honors of Lenz include the Benjamin Smith Reynolds Award for excellence in teaching, among other. Anonymous (1954). Lenz, Arno Thomas. Who’s who in engineering 7: 1433. Lewis: New York. Anonymous (1956). Arno T. Lenz. Civil Engineering 26(12): 696. P Anonymous (1963). Arno T. Lenz. Civil Engineering 33(6): 46. P Anonymous (1966). Arno T. Lenz. Civil Engineering 36(12): 71. P Anonymous (1992). Arno T. Lenz. Eos 73(49): 531. Lenz, A.T. (1943). Viscosity and surface tension effects on V-notch weir coefficients. Trans. ASCE 108: 759-802. Lenz, A.T. (1944). Estimation of stream-flow from alkalinity determinations. Trans. AGU 25(6): 1005-1011.
