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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.

This paper is focused on deriving a common solution to the strain energy release rate for delamination cracks in multilayered inhomogeneous beams under nonlinear creep. The layers of the beams exhibit material inhomogeneity in the thickness direction. The solution is obtained for the nonlinear stress-strain-time relation. The J -integral approach is applied to verify the solution. The variation of the strain energy release rate with time as a result of the nonlinear creep behaviour is analyzed.

The paper considers the solution of the plate flutter problem with mixed boundary conditions. The mathematical formulation of the problem allows taking into account arbitrary directions of the incoming flow vector. For the numerical solution of the problem, a modern numerical algorithm without saturation is proposed, which allows obtaining the critical flutter speed with sufficient accuracy on a sparse grid. The results of calculations for four materials are presented: titanium, steel, aluminum, duralumin. Based on the calculation results, two analytical dependences for the critical flutter speed are obtained: from the direction of the incoming flow vector, as well as from the dimensionless speed of sound in the plate and the thickness of the plate. The eigenforms Re(φ) corresponding to the critical flutter speed are given.

A technology for obtaining hybrid nanocomposite materials with a 7075-T6 aluminum matrix and a filler in the form nanoparticles is proposed. A review of experimental data and computer and theoretical models of crack initiation processes is presented. The mechanisms of microcrack nucleation under uniaxial tensile load are determined. To study the fracture of loaded nanocrystalline materials and determine their mechanisms, a model is proposed that describes the formation and growth of nanocracks near the tips of elliptical cracks in a hybrid nanocomposite material. The dependences between the applied force and the crack length are obtained using the parameters of a modeled crack.