Michail Norkin

This paper is concerned with the problem of the initial stage of motion of a rigid body in a perturbed liquid when its speed decreases under the linear law. A special feature of this problem is that at large accelerations there are areas of low pressure near the body and attached cavities are formed. Generally the zone of separation is an incoherent set. An important aspect of this study is the problem definition with boundary conditions like inequalities on the basis of which initial zones of separation of particles of the liquid and forms of internal free borders of the liquid on small times are defined. An example is considered in which the initial perturbation of the liquid is caused by a continuous dispersal of the circular cylinder under the free surface of the heavy liquid. A special asymptotic method (like the alternating method of Schwartz) based on the assumption that the free surface of the liquid is at large distances from the floating body is applied to the solution of the last problem.