Konstantin Petrovič Voronjec was born on January 30, 1902, in Kiev, in a family of well-known Russian scientist on mechanics (dynamics of nonholonomic systems), Petar Vasiljevič Voronjec, professor of the Kiev Uni¬versity. After completing the elite Kiev Gymnasium, Konstantin Voron^c was mobilized by the White Army, and took part in some of the most difficult battles against members of the Red Army, during 1919-1920. After the break of White Army, together with the thousands of refugees he escaped to Belgrade, Serbia.

He graduated from the Faculty of Philosophy in Belgrade, group for mathematics and physics. For a short time he taught at gymnasium in Kruševac. At the end of 1920 he returned to Belgrade and set up all his efforts to prepare his doctoral dissertation, entitled: Rolling of a solid body over an elastic support, which he defended in 1930. Members of his docto¬ ral committee were Anton Bilimovič, mentor, Milutin Milanković and Mihajlo Petrović. Subsequently he went to Paris, France, and took the post at the Institute for Fluid Mechanics of the French Ministry of Air Crafts. In France, under the supervision of professor Henri Villat, at the Faculty of Science of the Paris University he defended another doctoral dissertation that consisted of two parts, one of which related to stability of convective fluid flows, the other to fluid flow in thin layers over curved surfaces.

At the end of 1935 professor Voronjec returned to Belgrade, and as he could not find appropriate job at the University, he got employed at the insurance company, and worked there for 12 years. He joined the Mechanical Engineering Department of the Technical Faculty in 1947, and in 1954 he was elected full professor. He was the only Russian refugee who, having graduated at the University of Belgrade and having spent the most of his career working in Yugoslavia, became a member of the Serbian Academy of Sciences and Arts – he was elected corresponding member in 1958, and full member in 1963. He retired in 1971, and died on October 19, 1974.

Professor Voronjec, besides the problems that he studied in his doctoral dissertations, also addressed so called hydraulic analogy, i.e. analogy between incompressible and compressible fluid flow, problems of hydrotec-hniques, gas dynamics, and the application of non-analytic functions and monogenic quarternious in fluid mechanics. His scientific work was characterized by precise physico-mathematical modelling of a problem and its exact mathematical treatment. Mathematical apparatus that he used was on a high level. Respectively, he was using so-called inverse methods for the solution of fluid flow problems. He published 43 scientific papers and 4 university text-books: two for graduate and two for post-graduate studies.

Professor Voronjec was very active at the Mechanical Engineering Faculty. He was one of the founders, and very active member of the Yugoslav Society for Mechanics (posthumous he was awarded an honorary member of the Society) and of the Department for Mechanics of the Mathematical Institute of the Serbian Academy of Sciences and Arts. For some time he served as the chairman of this Department and headed Study group for mechanics of the Faculty of Natural Sciences and Mathematics in Belgrade.