Bykov

The authors consider numerical simulation of interior ballistics of cylindrical-conical barrels and describe mathematical models of propellant and plastic medium in mass Lagrangian coordinates. The numerical solution was obtained by using a simplified Neumann finite-difference scheme. It is shown that the use of a cylindrical-conical barrel with a plastic body allowed to increase the initial velocity of the projectile by about 1.5 times compared to classical schemes.

The author briefly describes the theory of acoustic resonator based on the corrugated tubes. For easy understanding, a situation with medium at rest inside a corrugated tube was considered. Classical solutions for the resonator were obtained. It was shown that the described structure could serve as an acoustic analogue of the optical resonator. Generalizations for the case of moving medium were made.