- Graetz number
fluid dynamics, the Graetz number (Gz) is a dimensionless numberthat characterises laminar flow in a conduit. The number is defined as:
:"di" is the internal diameter in round tubes or hydraulic diameter in arbitrary cross-section ducts
:"L" is the length:"Re" is the
Reynolds numberand:"Pr" is the Prandtl number.
When used in connection with mass transfer the Prandtl number is replaced by the
Schmidt numberwhich expresses the ratio of the momentum diffusivity to the mass diffusivity.
The quantity is named after the physicist
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Graetz — or Grätz is a German surname and place name and can refer to:* Heinrich Graetz (1817–1891), the first modern historian to write a comprehensive history of the Jewish people from a Jewish perspective * Leo Graetz (1856–1941), German physicist and… … Wikipedia
GRAETZ — GERMANY (see also List of Individuals) 26.9.1856 Breslau/PL 12.11.1941 Munich/D Leo Graetz studied mathematics and physics at the Universities of Breslau, today s Wrocław in Poland, Berlin and Strasburg. From 1881 he was an assistant at Strasburg … Hydraulicians in Europe 1800-2000
GRAETZ, HEINRICH — (Hirsch; 1817–1891), Jewish historian and Bible scholar. Graetz was born in Xions (Ksiaz Wielkopolski), Poznan, the son of a butcher. From 1831 to 1836 he went to the yeshivah in Wolstein (now Wolsztyn) near Poznan. At the same time, Graetz… … Encyclopedia of Judaism
Leo Graetz — (September 26, 1856 ndash; November 12, 1941) was a German physicist. He was born in Breslau (Wrocław), Poland as the son of the historian Heinrich Graetz.Graetz was one of the first to investigate the propagation of electromagnetic energy. The… … Wikipedia
Heinrich Graetz — (October 31, 1817 September 7, 1891) was amongst the first historians to write a comprehensive history of the Jewish people from a Jewish perspective.Born Tzvi Hirsh Graetz to a butcher family in Książ Wielkopolski (Poznań) in Germany (now in… … Wikipedia
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