Study on the Influence of Explosive Types on Rod Jet

In order to study the influence of explosive type on the rod jet formation of energetic composite liner, the process of rod jet formation of this liner is numerically simulated by using finite element analysis and multi-material Euler algorithm. In this paper, the rod jet formation and penetration performance of the liner are studied and analyzed by combining relevant theories and simulation calculation, and the influence law of explosive type on rod jet formation and target penetration thickness is obtained. In this paper, the stability of rod jet formed by this kind of model is verified by numerical simulation, and the influence law of explosive type on rod jet is obtained by simulating the collected data such as effective mass, tip velocity and jet length of rod jet and the equivalent target penetration thickness obtained by the quasi steady incompressible ideal fluid theory of jet penetration; it provides data support and design basis for the application of new explosives in energetic composite liner in the next stage.

Hydrodynamic Forces Exerting on an Oscillating Cylinder under Translational Motion in Water Covered by Compressed Ice

This paper presents the calculation of the hydrodynamic forces exerted on an oscillating circular cylinder when it moves perpendicular to its axis in infinitely deep water covered by compressed ice. The cylinder can oscillate both horizontally and vertically in the course of its translational motion. In the linear approximation, a solution is found for the steady wave motion generated by the cylinder within the hydrodynamic set of equations for the incompressible ideal fluid. It is shown that, depending on the rate of ice compression, both normal and anomalous dispersion can occur in the system. In the latter case, the group velocity can be opposite to the phase velocity in a certain range of wavenumbers. The dependences of the hydrodynamic loads exerted on the cylinder (the added mass, damping coefficients, wave resistance and lift force) on the translational velocity and frequency of oscillation were studied. It was shown that there is a possibility of the appearance of negative values for the damping coefficients at the relatively big cylinder velocity; then, the wave resistance decreases with the increase in cylinder velocity. The theoretical results were underpinned by the numerical calculations for the real parameters of ice and cylinder motion.

Movement of fluid inside the sphere

The paper presents an exact analytical solution of the stationary problem of an incompressible ideal fluid flow inside a sphere under the action of an external potential mass force.

Movement of Fluid Inside the Sphere

The paper presents an exact analytical solution of the stationary problem of an incompressible ideal fluid flow inside a sphere under the action of an external potential mass force.