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Based on the volume-of-fluid (VOF) multiphase model and the fluid-structure interaction (FSI) model, combined with the overset grid technology of the STAR-CCM+ software, a computational model for the oblique entry of truncated projectiles into water is established. The hydrodynamic characteristics and structural response characteristics of the projectile for various water entry angles are calculated and analyzed, and the evolution law of cavitation is determined. The numerical results are found to be in good agreement with experimental data

The parameters of the plasma generated by an arc discharge in gaseous helium at pressures of 3, 25, and 50 torr are studied experimentally and theoretically. The properties and orphology of synthesized soot are investigated by methods of the X-ray diffraction analysis, thermogravimetry, and transmission electron microscopy. A theoretical model is used to predict the radial distribution of the gas temperature, which is consistent with the results of thermocouple measurements. It is demonstrated that a change in the pressure in the arc discharge alters the residence time of carbon vapor in various temperature regions. This fact ensures different conditions of formation of carbon nanostructures and allows obtaining soot with essentially different structural and physical properties.

The influence of sinusoidal pulsations of the flow rate of the dispersed phase on the flow characteristics of immiscible high-viscosity liquids in a T-shaped microchannel has been studied. The flow regimes in the unperturbed flow and in the flow subjected to external perturbations with different frequencies and amplitudes were visualized. A dimensionless complex is proposed that describes the transition from parallel to plug flow due to external pulsations for a fixed capillarity number of the carrier phase. The application of perturbations to the plug flow regime is found to lead to flow stabilization and to a reduction in the spread of values of the generated plugs at a frequency equal to the natural frequency of plug separation in the unperturbed flow. The average length of the plugs and the spread of its values are shown to increase with decreasing perturbation frequency.

The paper presents an analytical solution of the problem of stress relaxation in a bended viscoelastic plate. The effect the difference in the viscous properties of the material in tension and compression on the relaxation of the bending moment is investigated. The deformation is assumed to be finite, and the multiplicative decomposition of the deformation gradient tensor into elastic and inelastic components is used. Two different material models with tension-compression asymmetry are compared

Since in modern high-performance sports, the technical component is decisive, an important element of skiing race is the sliding surface of skis. This paper presents a review of papers on sliding mechanics and discusses modern ways to improve it and prospects for the development of this area in modern energy and environmental conditions. A detailed analysis of various factors affecting the sliding mechanics, in particular, snow cover albedo, and microroughness of the sliding surface of skis is given

The efficiency of two ways to reduce vibration and sound emission of a plate made of paper-laminated plastic (high-pressure laminate) has been investigated. It has been found that the inclusion of a polymer polyvinyl acetate film in the plastic structure or using constrained damping layer treatments based on polyvinyl acetate film and aluminum foil or plastic leads to a significant improvement in its vibroacoustic characteristics. The greatest reduction in vibration and sound emission was obtained when applying a coating with aluminum foil whose thickness was six times less than that of the damped plastic plate

The solution of the system of nonlinear elasticity equations was found the described the stress-strain state of a two-layer incompressible material. The solution can be used to describe the compression of a two-layer material by rigid plates that approach each other with constant acceleration

This paper describes the use of a nonlinear viscoelastic model with material properties depending on the strains in the lengthwise fracture analysis of an inhomogeneous cantilever beam structure. The viscoelastic model is obtained by placing a~nonlinear spring and a nonlinear dashpot in parallel to a series of a linear spring and a linear dashpot. The modulus of elasticity of the nonlinear spring and the coefficient of viscosity of the nonlinear dashpot depend on strains. The strain energy release rate is determined. The balance of the energy is analyzed to prove the correctness of the strain energy release rate solution.

A method for determining the limiting expansion coefficient of cylindrical pipes using conical equipment is considered which allows a fairly accurate calculation of the moment of fracture of a workpiece taking into account the nonlinear plasticity of the material and the change in thickness. The method is based on the use of forming limit diagrams to predict the fracture of the workpiece and the method of variable elasticity parameters to determine the stress-strain state

Implementation of the Candler model of vibrational-vibrational energy transfer between diatomic molecules in an inelastic collision is discussed. An example of oxygen O₂ and nitrogen N₂ interaction is used to analyze the method of simple iterations, the Newton method, the method of bisection, and the approximate formula for calculating the equilibrium vibrational temperature, which is necessary in the Candler model. The method recommended for simulations is the Newton method or bisection. The model of vibrational-vibrational energy transfer is tested by examples of zero-dimensional vibrational relaxation, the flow around a cylinder, and the flow in a wedge-shaped nozzle. It is demonstrated that vibrational-vibrational energy transfer affects the distribution of vibrational temperatures