Kochin, Nikolai Evgrafovich

Born May 6 (19), 1901, in St. Petersburg; died Dec. 31, 1944, in Moscow. Soviet scientist in mechanics, mathematics, and geophysics; one of the founders of modern dynamic meteorology. Academician of the Academy of Sciences of the USSR (1939).

Kochin graduated from the University of Petrograd in 1923. As a student he was drafted into the Red Army and took part in operations against ludenich and in putting down the Kronstadt rebellion. He taught at the Universities of Leningrad (1924–34) and Moscow (1938–4). From 1933 to 1934 he was director of the Institute of Theoretical Meteorology, and in 1939 he became head of the department of mechanics of the Institute of Mechanics of the Academy of Sciences of the USSR.

Kochin’s main works were in dynamic meteorology, hydrodynamics and aerodynamics, mathematics, and theoretical mechanics. He demonstrated the possibility of motion of a compressible liquid under the influence of conservative forces, with the formation of eddies in the absence of an influx of energy from without (1923); solved the equation for the movement of a compressible liquid on the rotating earth (1924); and determined the conditions of zonal circulation of the atmosphere. He worked on the problems of cyclone formation and of the general circulation of the atmosphere and substantiated the long-wave method in problems of dynamic meteorology. He laid the foundation of a method for determining fields of velocity and pressure depending on the field of temperatures. Kochin’s research on strong disturbances (shock waves) in a compressible liquid (1924–25) was of great importance for the development of gas dynamics.

In hydrodynamics, Kochin conducted research on the precise type of waves of finite amplitude on the interface of two liquids of finite depth (1928) and solved the problems of small-amplitude free waves on the surface of an incompressible liquid (1935). He proposed a method of solving the planar hydrofoil problem (1937) and formulas for the resistance of a ship, for the shape of a wave surface, and for the lifting force and solved the planar problem of a slightly curved contour planing on the surface of a heavy, incompressible liquid (1938). He laid the foundations of the theory of the rolling of ships, taking into account the interaction of the ship’s hull and the water. In 1941–44 he was the first to give a strict solution for the problem for a wing of finite span. He was the author of textbooks on hydromechanics and vector calculus and the coauthor and editor of a two-volume mono-graph on dynamic meteorology.