RUBACH

GERMANY (see also List of Individuals)

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6.9.1888 Güstrow/D - 11.6.1956 Glücksburg/D

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Hans Ludwig Rubach originated from a small city close to Mecklenburg. His father passed away when being ten years old. Rubach joined in 1908 the German Army but was granted leave shortly later because of an appendicitis. After two years of study at Kiel University, he moved in 1910 to Göttingen University and gained there in 1912 his diploma in mechanical engineering. Rubach made his PhD study under Ludwig Prandtl (1875-1953) from 1912 to 1914 and later may have been forced to join the German Army again for World War I. Nothing is known from his life after the research work had been accepted from Göttingen University.

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The PhD thesis is Rubach's only publication, once at the University of Göttingen and once as Forschungsarbeit of the VDI Organisation. The PhD thesis was dedicated to his father. The work considers a fundamental problem in hydraulics, namely the flow pattern in the wake zone of cylindrical bodies. As described in the 1968 auto-biography of Theodor von Karman (1881-1963), Rubach tried for months in vain to establish experimentally the flow features of vortices developed in the wake zone of a circular-shaped cylinder. Prandtl, his adviser, proposed to improve the cylinder geometry because minute imperfections could have resulted in the unsteady vortex flow. Each morning when von Karman went through the laboratory, he asked Rubach whether the flow has improved, and for months heard from Rubach the answer: No, there is no improvement of the flow. This problem led von Karman to his famous work on the von Karman vortex street, and Rubach to the description of a stable two-cell vortex pattern in the wake of a cylinder for welldefined cylinder Reynolds numbers.

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_{Franz, B. (2006). Hans Ludwig Max Philipp Rubach. Personal note. Standesamt: Güstrow. Hunger, U. (2005). Hans L. Rubach. Personal communication. Universitätsarchiv: Göttingen. Karman, T. von (1968). Die Wirbelstrasse - Mein Leben und die Luftfahrt. Hoffmann und Campe: Hamburg.}

_{Rubach, H.L., Karman, T. von (1912). Über den Mechanismus des Flüssigkeitswiderstandes und Luftwiderstandes. Physikalische Zeitschrift 13: 49-59.}

_{Rubach, H.L. (1914). Über die Entstehung und Fortbewegung des Wirbelpaares hinter zylindrischen Körpern. Inaugural-Dissertation. Universität: Göttingen.}

_{Rubach, H.L. (1916). Über die Entstehung und Fortbewegung des Wirbelpaares hinter zylindrischen Körpern. Forschungsarbeit aus dem Gebiete des Ingenieurwesens 185. Verein Deutscher Ingenieure: Berlin.}