[en] Considered are oscillations of round cylindrical rods in a rigid eccentric shell filled with a liquid. Nonlinearities of an added mass and hydrodynamic damping are determined. Small advance and rotational oscillations of prismatic rods in restricted volumes are considered, and added masses are evaluated as well as added inertia momenta and corresponding damping coefficients. Estimates of added masses and damping are presented for a cylindrical shell which oscillates in a restricted liquid volume. Even at a maximum possible oscillation amplitude nonlinearity of hydrodynamic time lag is shown to be sufficiently small and may be not taken into account while calculating natural oscillation frequencies of round rods. Added mass depends substantially on eccentricity in the case of oscillations of prismatic rods, and it goes into infinity at the contact of a face with the shell surface, which is different from added mass for a round rod. Hydrodynamic damping also goes into infinity in this case, but is grows quicker than for a round rod. The damping coefficient is similar for all the types of prismatic rods making advance or rotational oscillations, and it depends only on the liquid viscosity, of oscillation frequency and the width of a gap

[en] Characteristics of the simplest hydrodynamically coupled oscillating system consisting of a rod and a concentric tube are considered. A space hetween the rod and tube is filled with liquid. The liquid in the ring gap provides the rod-tube hydrodynamic coupling during their bending oscillations. The dependences of the coupled system oscillation eigen frequencies on the frequencies of isolated oscillating subsystems without liquid and hydrodynamic inertial coefficients, conditioned by liquid, are obtained. Coefficients of system dynamic properties are found, and their dependences on different system structural parameters and liquid properties are given

[en] The vibrations of tanks with liquid and non deformed cylindrical or spherical inclusions are considered. It is shown that for calculating dynamic characteristics of such systems it is advisable to use continual approach, i.e. consider heterogeneous media formed by liquid and weighted inclusions in it as homogeneous media with effective or vibroreological properties. On the base of the problem on vibrations of the tank, containing liquid and localized inclusion grouuel rod assembly vibrationp, f are considered and relationships for the added mass and resistance coefficient determining dynamic characteristics of such systems are obtained. Considered are also liquid tank vibrations containing spherical inclusions. The results obtained are used for calculating dynamic characteristics of two-phase flow pipelines at bubble and annular flow mode. The theoretical relatiships are compared with available experimental data

[en] A study was made on the dynamic behaviour of heterogeneous media formed by Newtonian liquids and undeformable inclusions under the action of vibrations on the liquid. Minor one-dimensional forward vibrations of heterogeneous media and their effective properties-translatory density and viscosity-corresponding with this type of motion were considered. The effective properties determine the dynamic characteristics of vibrational systems, contacting with the heterogeneous media. Particular types of heterogeneous media with spherical and cylindrical inclusions simulating two-phase bubble media and rod assemblies submerged in the liquid were considered. The ultimate cases with light and heavy inclusions giving the most typical dependences of the effective properties of heterogeneous media on the properties of phases forming them were analyzed

[en] The process of turbulent diffusion of particles in a dispersed drift flow has been investigated. A calculation of the coefficient of particle radial diffusion is performed on the basis of the spectral theory. In case of sufficiently high relative particle velocities, the diffusion coefficient has been shown to be proportional to the square of the transverse scale for radial vibrations and inversely proportional to the particle relaxation time and square of relative velocity. The calculation results, in order of magnitude, are in agreement with the experimental data for particles of 150 and 200 mm. For 80 mm particles with low relative velocities compared to the intensity of turbulent vibrations in the velocity of the carrying agent, the above formula proves to be inapplicable

[en] On the base of continual description of effective inertial properties of heterogeneous media formed by fluid and fluidixed in it non deformable inclusions, from Lagrange equations for a fluid element unsteady filtration equations of ideal fluid in porous medium are obtaiined. It is shown that the porous medium structure in this case is described by two characterisitcs - porosity and tensor of coefficients of attached masses of inclusions or skeleton of porous material. Considered is the flow in anisotropic porous media the macroscopic non uniformity of which may be caused by non uniformity of scalar porosity field as well as by non uniformity of tensor field of coefficients of attached masses. Considered are two types of porous media having different topologic structure; it is shown that the flow in them is described by the same filtration equations which are analogous to Eiles equations for continuous medium but with effective density expressed by the second rank tensor. For macroscopically non uniform porous media motion equations comprise additional terms having a substantial significance for problems of unsteady filtration in deformable porous media. The evaluations of effective density for flows in rod assemblies and granular media with spherical particles are given

[en] Weak oscillations of seherical and cylindrical inclusions in liquid are considered. Under the assumptions on unseparated flow around elements with formation of a thin boundary layer on their surfaces the exeressions for hydrodynamic forces containing inertia and viscous constituents are derived. For the systems with volume concentration of inclusions not too close to the limiting one the model of equivalent spherical and cylindrical cells is used. The condition of thickness insignificance of the boundary layer arising on sphere or cylinder surfaces at great oscillating Reynolds numbers is used for determining inertia forces in approximation of potential flow around body, while the wo-dimensionality of the boundary layer - for calculating viscous friction forces for oscillating motion. Considered are also the systems with volume concentration of inclusions close to the limiting one and on the e base of simple schematization of liquid flow in microcells the expressionsody for hydrnamic forces are derived. An attempt of determining hydrodynamic forces for the case of moderate and insignificant oscillating Reynolds numbers is made

[en] To specify the technique of calculation of oscillations of elastic constructions surrounded or containing liquid, oscillations of spherical bubbles assuming that the presence of surface-active substances provides boundary condition of liquid adhesion at its surface are considered. Relations for inertial and dissipative resistance forces, taking into account the bubble motion inconvenience in an oscillating liquid, are obtained. On the basis of the equation of bubble oscillating motion the formula is obtained for the two-phase mixture dynamic density taking into account volumetric gas content of mixture, bubble size liquid viscosity and oscillation frequency. Body oscillations with a cavity containing a two-phase bubble mixture are considered and the relation for the hydrodynamic damping coefficient du to dissipative losses in boundary layers at oscillating in relation to the liquid bubbles is obtained. The above results spread over the case of pipeline vibrations with the occuring two-phase bubble flow

[en] Dynamic behaviour of heterogeneous media formed with incompressible liquid and elastically fixed inclusions contained in it under vibration conditions affected liquid is considered. Effective inertial and viscous properties of such heterogeneous media are introduced and their time dispersion characteristics are studied. Analysis of effective properties in low-frequency, high-frequency and resonance vibrational effects is given, limiting ratios for heterogeneous media with free and fixed inclusions have been obtained. Effective inertial and viscous properties of heterogeneous media are shown to have close analogy to permittivity. As an example of the theory application the ratios obtained were used for calculating eigenfrequencies of body oscillations with a cavity filled with heterogeneous medium serving as the simplest model of fuel assembly

[en] Small vibrations of a body having a cavity with liquid with gas bubbles are considered. A part of a pipeline with a flowing gas liquid mixture can be considered as an example of such body. It is shown that because of the relative motion of the bubbles in liquid the suspension dynamical density differs from the ''statical'' density. In the approximation of the potentiality of liquid flow among the bubbles it has been found that the dynamical density in the case of suspension vibrations depends on the volume gas content of the mixture, bubble size, liquid viscosity and vibration frequency. At rather high frequencies (ω > 18 ν ) a², where ν is kinematic liquid viscosity, a is the bubble radius, the dynamical density is defined only by the volume gas contentt of the suspension. It is also shown that the gas bubble suspension has damping properties. The damping of vibrations of the body with the gas-liquid suspension, caused by the bubble relative motion and corresponding energy dissipation, is also defined by the volume gas content, bubble size, liquid viscosity and vibration frequency of the system. On the basis of the results obtained the vibrations of an elastic cylindrical rod in a concentrical shell filled with the gas-liquid suspension