Adhémar Barré de Saint-Venant

Adhémar Jean Claude Barré de Saint-Venant (23 August 1797 to 6 January 1886) was a mechanician and mathematician, born at the château de Fortoiseau at Villiers-en-Bière in Seine-et-Marne, France, who contributed to early stress analysis. He developed the unsteady open channel flow shallow water equations, now called the Saint-Venant equations, which are a basic tool of hydraulic engineering. His name is also attached to Saint-Venant's principle of statically equivalent systems of load, to Saint-Venant's theorem and to Saint-Venant's compatibility condition for strain. In 1843 he published the correct derivation of the Navier-Stokes equations for viscous flow, and in 1845 he published a form of vector calculus similar to Grassmann's, which led to a priority dispute because Grassmann had published in 1844.