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The protective performance of a three-layer explosive welded composite plate consisting of steel and aluminum plates is studied in ballistic experiments and numerical simulations. The mechanism of target plate failure under the impact of spherical fragments is investigated.

Variational formulations are proposed for the equations describing the stationary states of nonisothermal one-dimensional reactors, including those under convective transfer. For the proposed variational formulations, several variants of the numerical solution are considered (based on the method of local variations and the Rayleigh-Ritz method). The features of the use of numerical methods in solving the considered problems are discussed: convergence, the ratio of the spatial grid step to the degree of the approximating polynomial. Modifications of the problem of thermal ignition are considered taking into account convective transfer and heat losses. A variational principle is proposed that determines the structure of the combustion front at a given propagation velocity. It is shown that this variational principle can be used along with the principle of minimum entropy production for a complete solution of the problem of stationary propagation of an exothermic reaction wave.

Results of studying the problem of an unsteady fluid flow along an instantaneously stretching (shrinking) non-rotating disk with an infinite radius are reported. The velocity of the shrinking disk surface is chosen in such a way that the problem allows the existence of an exact similarity solution. The original problem is reduced to an initial-value problem, which is solved numerically by using the shooting and Newton-Raphson methods. A detailed study of the existence and uniqueness of the solution is performed.

This study deals with axisymmetric steady rotational movement of an incompressible couple stress fluid between two non-concentric objects. Two spherical boundaries are revolving axially with different angular velocities. At low Reynolds numbers, the solution is obtained semi-analytically utilizing the superposition guideline and the collocation approach. The hydrodynamic couple exerted by the fluid on the internal particle is considered. The results obtained in the study are compared with the corresponding results of the classical viscous fluids available in the literature.

Experiments on acceleration of flat metal liners by a magnetic field were performed on the Kaskad capacitor facility. Data on the asymmetry of the flight of liners both along the streamline and in the transverse direction are presented.

The accelerated motion of a circular cylinder from the state of rest under the free surface of an infinitely deep ideal fluid is studied using the method of reducing the original mathematical formulation of the problem to an integrodifferential system of equations for the function specifying the free surface shape and for the normal and tangential velocity components on the free surface. An analytic continuation of the velocity field into the flow region is constructed and unsteady loads acting on the cylinder at the initial stage of motion are determined.

The transition of a filtration reactive flow in a double porosity medium into a self-oscillating mode is studied. Flow stability is analyzed using numerical methods for solving multiphase filtration equations in a medium with double porosity. The region of development of self-oscillations is investigated depending on the external parameters of the system and the properties of the reagents.

Numerical and experimental methods are used to investigate the aerodynamic characteristics of a laboratory sample in the form of a cylinder with an active rotating element - a deflector-that can be used as a working power blade element of awind power plant. Numerical simulation was performed using the Ansys Fluent software based on the Reynolds-averaged Navier-Stokes equations supplemented by a realizable (κ-ε)-turbulence model. Based on the results of numerical simulation, a laboratory model with a cylinder 205 mm long and 50 mm in diameter and a deflector 100 mm in diameter was made for experimental studies. A comparative analysis of the numerical and experimental aerodynamic characteristics of the model was carried out and the aerodynamic features of the airflow around the test sample were identified.

A two-dimensional stationary linear model of flows arising in a stably (neutral) stratified medium over a thermally inhomogeneous flat inclined surface is analyzed analytically. At the lower boundary, temperature deviations are specified, which depend harmonically on the horizontal coordinate transverse to the slope. Explicit analytical solutions are obtained, which make it possible to analyze the regularities of emerging density flows. It is shown that these flows can qualitatively differ depending on the ratio of the slope angle of the lower boundary and the analog of the Rayleigh number, the expression for which includes the horizontal scale of the thermal inhomogeneity region as a spatial scale. An appropriate criterion for distinguishing these currents is established.

The reflection and transmission of harmonic waves is theoretically investigated at the interface between a bubbly liquid and a porous medium saturated with this liquid has been studied theoretically. The influence of the parameters of the system on the coefficients of reflection and transmission through the interface between the two media has been investigated. It has been found that for the interface between the bubbly liquid and the porous medium saturated with the bubbly liquid, there is a range of frequencies in which reflection occurs in the same way as from a free surface and the back reflection as from a rigid wall.