KHRISTIANOVICH Sergey Alekseyevich (born in 1908) - the Soviet scientist in the field of mechanics (of hydro- and aerodynamics, of explosion dynamics, of toughness and plasticity), together with mining and power. Academician of AS USSR since 1943 (corr. memb. since 1939), Hero of Soc. Labour (1969).

He has graduated from Leningrad state university (1930), worked in the State hydrological institute (1930-1935), CAHI (1937-1953, since 1942 - chief institute deputy). He is one of the organizers of Siberian Branch of AS USSR. In 1957-1961 - the vice-president of the Siberian branch. In 1957-1965 - director of Institute of theoretical and applied mechanics. In 1965-1972 he is the supervisor of studies of All-Union Scientific Research Institute of physicotechnical and radiotechnical measurements. Since 1972 he is the head of the laboratory of nonlinear media mechanics of Institute of problems of mechanics of AS USSR.

He was the professor in Leningrad and Moscow universities, Novosibirsk State University; he was one of the organizers of the Moscow Institute of Physics and Technology.

As he headed the laboratory of high speeds in CAHI, and as the supervisor of institute studies in aerodynamics, Khristianovich was bound up with the creation of high-speed aircrafts, actively participated in modernization of CAHI, in updating of the experimental support, including pipes with the punched walls for investigations involving the overstepping of sound speed. He has got the important results on air compressibility effect on the streamlines of the wing section, and formulated the requirements the wing sections should satisfy when made for the high subsonic speeds of flight (1939-1940).

Khristianovich's works of the post-war period cover the flight modes with high subsonic, trans- and supersonic speeds, the theory of the airscrew, Laval nozzle and of an ejector. Khristianovich's work has the great influence on formation of the large scientific groups in the country.