ANDERSSON

SWEDEN (see also List of Individuals)

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13.2.1854 Julita/S - 5.6.1911 Stockholm/S

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Erik Andersson was born in the Södermanland Province. He graduated as a civil engineer from the Royal Technical University of Stockholm in 1878 and there remained as an assistant of the engineering institute until 1895. He there lectured in mechanics, mechanical engineering and hydraulic engineering. He was in parallel a consultant for the Trollhättan hydropower plant. He then joined the Swedish turbine institute and there developed both machinery and methods to determine discharge for precise turbine performance tests.

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Discharge measurements in rivers by the Area and velocity method are almost entirely free of energy losses. Velocities are measured across the river section because of transverse and vertical variations, and because the location of the average cross-sectional velocity is previously unknown. Early observations were conducted in the 1840s with a gage-wheel of 5 m diameter across a supply canal from the Merrimac River in Massachusetts. The flowing water rotated the submerged paddles and revolutions were counted by a clock work; the discharge was up to 20 m3/s. Later, the average velocity in a regular channel was measured by a hydrometric screen attached to a light carriage. Flowing water moves the carriage on rails along the channel. The time needed to travel a certain distance and the depth of water allow the determination of the discharge. This method was introduced by G.-A. Hirn (1815-1890) in France in 1846 as a float with a screen. Andersson applied the method for turbine testing in 1905 in Sweden, known there as the Andersson skräm. Ernst Reichel (1857-1934) made tests in 1908 for the Nottoden power plant in Norway, whereas Otto Lütschg (1872-1947) determined discharge with the screen method at the Ackersand power plant in Switzerland in 1910. Later, this method was mainly used in hydraulic laboratories because of the ease and the simple conditions which were not available outside. As compared with the presently applied Area and velocity method, the screen method is simple but no more used from the 1950s because of limited accuracy.

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_{Anonymous (1911). Erik Andersson. Teknisk Tidskrift 41(24): 105-106. P}

_{Kolupaila, S. (1960). Water measurements in hydraulic structures and power plants. La Houille Blanche 15(4): 344-363. P}

_{Westergren, T. (2007). Erik Andersson. Library of Science and Technology. Royal Technical University: Stockholm.}