Gavrylenko O. Unsteady interaction of hard body with a cavity in compressible fluid.

The dissertation deals with the development of general approach to the solution of the problems of impact of hard bodies on a surface of cavity, which belong to un-steady mixed and unmixed boundary problems of mechanics with compressible fluid with movable beforehand unknown variable boundary that changes with time. The new classes of practically important problems of penetration of hard bodies into fluid through the surface of cavity were solved on the base of this numerical and analytical approach. While solving this problems we found hydro mechanical and kinematical characteristics of the process for different weight of a body, the initial speed of body's movement, the gap between a cavity and a body. We investigated the impact of various boundary conditions on free part of surface of cavity on the process of penetration.