Aurel Stodola

Born May 10, 1859, in Liptovsky Mikulás, now in Czechoslovakia; died Dec. 25,1942, in Zurich. Slovak engineer and scientist in the field of heat engineering.

Stodola graduated from the Polytechnic University of Budapest in 1878 and from the Technische Hochschule in Zurich in 1881. In 1883 and 1884 he studied at the universities of Berlin and Paris and at the Technische Hochschule in Berlin. From 1884 to 1892 he worked in machine-building plants. He was a professor at the Technische Hochschule in Zurich from 1892 to 1929.

Stodola’s research dealt mainly with the thermodynamic and aerohydrodynamic theories and with the analysis of steam and gas turbines, as well as with the theory of automatic control and the theory of circulation in centrifugal compressors. He studied nozzles operating in variable regimes, and he investigated the conversion of energy at turbine blades, the leakage of steam through labyrinth seals, and the supercooling of steam upon exhaust. Stodola proposed engineering methods for analyzing turbine vibrations and the strength of the blades, disks, shafts, and rotors of high-speed steam turbines (Laval turbine), and he extended the methods of I. A. Vyshnegradskii for analyzing direct-action regulators to systems of indirect control. In his research on the stability of control systems, begun in the 1890’s, he posed the mathematical problem that came to be known as the Hurwitz problem.