Ludwig Prandtl - Assignment # 5

A little known physicist, by the name of Ludwig Prandtl, is considered the father of modern aerodynamics. He was born Feb. 2, 1875 to Alexander Prandtl, a professor of surveying and engineering at the agricultural college at Weihenstphanand. He spent most of his time with his engineer father because of his mother’s lengthy illness. He grew up as an only child because two earlier children died at birth. He graduated from Technische Hochschule Munich in 1900 after only spending 6 years to obtain his Bachelors, Masters, and PhD in Solid Mechanics.

At the age of 29, he was a professor at his alma mater and presented at the Third International Mathematics Congress. His ten minute presentation introduced the concept of boundary layer flow over a surface. This presentation, which revolutionized the understanding and analysis of fluid dynamics, was published in only 8 pages. The work he did helped the Germans develop more sophisticated airplanes in WWI. He theorized that an effect of friction was to cause fluid immediately adjacent to the surface to stick to the surface, assuming a no-slip condition on the surface and thusly only experienced in the boundary layer, a thin region near the surface. This boundary layer has very large velocity gradients thusly the skin-friction drag force is the majority of the drag on the body. Prandtl was never awarded a Nobel Prize for his work in fluid dynamics because rumor had it that the Committee was reluctant to award the prize for work in classical physics.

The Lanchester-Prandtl wing theory, mathematical tool for analyzing lift from “real world” wings, was published in 1918-1919. The first theories about supersonic shock waves and flow came from Prandtl and Theodore Meyer, one of his students, in 1908. He didn’t continue working on the theory till the 1920s. Adolf Buseman worked with Prandtl to developed a method for designing a supersonic nozzle in 1929. Prandtl worked with Riech’s Air Ministry, particularly Hermann Goring earlier to and during World War II. He also worked in such areas meteorology, plasticity, and structural mechanics. He died in 1953 on August 15th.

A PDF about Ludwig Prandtl’s Boundary Layer, biography of his life, and pictures of the man can be found at: http://www.math.lsa.umich.edu/~krasny/math654_prandtl.pdf

Additional information about his life’s contributions can be found here: http://www.uh.edu/engines/epi1539.htm