Ludwig Prandtl

Born Feb. 4, 1875, in Freising, Bavaria; died Aug. 15, 1953, in Göttingen. German scientist in the field of mechanics. One of the founders of aerodynamics. Prandtl graduated from the Polytechnische Hochschule in Munich. In 1901 he became a professor at the Technische Hochschule in Hanover, and in 1904 at the University of Göttingen. He served as director of the Kaiser Wilhelm Institute for Fluid Mechanics in Göttingen from 1925 until 1947.

Prandtl’s major works were on the theory of elasticity and plasticity and on fluid mechanics, gas dynamics, and dynamical meteorology. In 1904, Prandtl introduced the concept of boundary layer and explained the drag exhibited when fluid flows past a body as being due to the separation of this layer. He developed the theory of the finite span of airplane wings and worked out methods for the simplified solution of the corresponding equations. He studied the optimal distribution of airflow over the wing and, in conjunction with Birnbaum, examined the case of a nonstationary solution. He also introduced a clear concept of induced resistance and provided the formula for its determination. Prandtl studied turbulent flow in tubes, the turbulence of the free atmosphere, and the transition from laminar to turbulent flow. He investigated the supersonic discharge of gases and vapors under pressure and developed a linearized theory for a wing in a subsonic flow of compressible gas.

Various equations, concepts, and instruments have been named after Prandtl, who was responsible for a new approach to the study of applied fluid mechanics.