Diffusiophoresis of an aerosol particle in a binary gas mixture

The diffusion force and rate are calculated for the diffusiophoresis of a spherical particle in a binary gas mixture by solving the gas–kinetic equations. Two schemes of diffusiophoresis are considered: constant–pressure diffusion and diffusion of one mixture component through the other fixed component. The problem is solved by the integral–momentum method at arbitrary Knudsen numbers. Diffuse scattering of the gas molecules on the particle surface is assumed. The Lorentzian and Rayleigh models of a binary gas mixture are considered. The dependences of the force and rate of diffusiophoresis on the Knudsen number and the other determining parameters are analyzed. The results obtained are compared with well–known experimental data.     

Pressure pulsations on the surface of a sphere in a subsonic stream

Many data are available on the drag C_x and the distribution of the static pressure over the surface of a sphere [1, 2]. However, there are virtually no data on pulsations of the pressure over the surface of a sphere. In the present paper, the results are given of an investigation of the total and spectral levels of the pressure pulsations at different points of the surface of a sphere at M 0.5–1.0 and Re (1.7–2.7)·.10⁶. It was found that the strongest pressure pulsations occur on the side in the region of the angle 90°. In this region at M 0.6–0.8 the relative total level o/q where q is the velocity head in the oncoming stream, reaches values 0.18–0.22. It was established that at M = 0.7–0.9 narrow-band maxima occur in the spectra of the pressure pulsations at frequencies Sh fD/V = 0.2–0.3. Data are also presented on the pulsations of the base pressure behind a spherical segment with short cylindrical and conical trailing edges.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 164–168, September–October, 1981.     

Some laws for precipitation of aerosols on a charged collector in the reynolds number range 10–100

Experimental data are presented on the efficiency of electrostatic precipitation of aqueous aerosol particles on a strongly charged sphere in the medium Reynolds number range (Re = 10–100). The asymptotic solutions for the problem are presented, and typical errors allowable in interpreting this type of experiment are discussed.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 3, pp. 190–193, May–June, 1976.     

Small vibrations of a sphere in a spherical volume of viscous fluid

Problems of the vibration of bodies in confined viscous fluids have been solved to determine the added masses and damping coefficients of rods [1–3] and floats [4–5]. The solutions of these problems, based on the use of simplifications of the boundary-layer method [4–6], are obtained analytically in general form and are in good agreement with the experimental data. However, in each specific case the possibility of using such solutions for given values of the fluid viscosity and vibration frequency must be justified either experimentally [2, 4, 5] or theoretically as, for example, in [1], where an analytic solution was obtained for concentric cylinders. The present paper offers a general solution of the problem of the small vibrations of a sphere in a spherical volume of fluid valid over a broad range of variation of the dimensionless kinematic viscosity. The limiting cases of this solution for both high and low viscosity are considered. The asymptotic expressions obtained are compared with calculations based on the analytic solution.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 29–34, March–April, 1986.     

Supersonic transverse rarefied gas flow past a strip

The supersonic flow of a monatomic gas consisting of hard spherical particles past a flat strip normal to the flow is investigated using the direct simulation Monte-Carlo (DSMC) method. The calculations are performed over the Knudsen and Mach number ranges 0.015–5 and 1.8–15, respectively. The structure of the compressed layer and the aerodynamic characteristics are systematically studied for the Mach number 5 and various Knudsen numbers. The dependences of the compressed-layer thickness in molecular free paths are found. The nonequilibrium processes in the neighborhood of the strip are described on the basis of the data on the temperature anisotropy with respect to three coordinates.__________Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, 2005, pp. 159–167. Original Russian Text Copyright © 2005 by Maltsev and Rebrov.     

Dispersion coefficient with the displacement of a gas from a porous medium by a gas

The article gives the dependence of the dispersion coefficient on the Péclet number, obtained with the analysis of experimental data on the displacement of a gas by a gas from a porous medium of varying permeability.Translated from Zhurnal Prikladkoi Mekhaniki i Teknicheskoi Fiziki, No. 4, pp. 142–145, July–August, 1975.The authors are grateful to N. P. Baturina and L. N. Demidova for their aid in carrying out and analyzing the experiments, and to V. M. Ryzhik for evaluating the results of the work.     

Interaction of light with a turbulent liquid flow

The relation between the rms fluctuation of a light current and the density fluctuation in a turbulent liquid flow is considered. Criteria are established for the effect of medium turbulence on the refractive index and on light attenuation. Experimental apparatus and new experimental data are described.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 115–123, July–August, 1973.     

Experimental investigation of laminar-turbulent transition behind a three-dimensional roughness element in the boundary layer on a sharp cone

The qualitative characteristics of laminar-turbulent transition behind a three-dimensional roughness element in a zero-gradient boundary layer are investigated for high supersonic free-stream velocities. Quantitative data on the distribution of the heat transfer coefficient in the neighborhood of the roughness element and in the wake behind it are obtained. Another object of the investigation was to compare the data obtained for the position of the laminar-turbulent transition zone with well-known correlations used in practice.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 60–66, July–August, 1990.     

Development of Natural Disturbances in a Hypersonic Boundary Layer on a Sharp Cone

Experimental data on the location of the laminar—turbulent transition and development of natural disturbances in a laminar hypersonic boundary layer on a sharp thermally insulated cone with a half–angle of 7° are presented. The existence of the second mode of disturbances is confirmed. It is shown that the transition is determined by the first mode of disturbances. The experimental data are in good agreement with theoretical calculations.     

Interaction between a fast magnetohydrodynamic shock wave and a tangential discontinuity

The self-similar problem of the oblique interaction between a fast shock wave and a tangential discontinuity is solved within the framework of the ideal magnetohydrodynamic model. The constraints on the initial parameters necessary for the existence of a regular solution are found. Various feasible wave flow patterns are found. In the space of the governing parameters boundaries between the solutions of various types are constructed. The basic features of the developing flows and their dependence on the initial data are clarified.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 159–168, March–April, 1995.     

Structure and dynamics of finite-amplitude pressure perturbations in a porous medium saturated with gassy fluid

Experimental data on the structure and dynamics of pressure perturbations of moderate intensity in a porous medium saturated with a gassy fluid are obtained and generalized on the basis of a theoretical analysis.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp, 80–85, January–February, 1992.     

Momentum produced by intense radiation falling on a surface

The transient flow produced in a stationary gas when an intense beam of radiation falls on a plane surface is studied. A flow pattern is proposed and approximate relations are derived for finding the momentum produced by sufficiently long irradiation of the body. The calculations are compared with available experimental data.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2. pp. 196–199. March–April, 1977.     

Jet flow around a wedge-shaped stanchion intersecting a free space

A solution to the problem of a jet flow around a narrow wedge-shaped stanchion intersecting a free space is examined. The dimensions of the cavity formed behind the stanchion and the coefficient of resistance are determined. The results of the calculations are compared with experimental data.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 140–143, July–August, 1976.     

Thermocapillary convection in a liquid layer with local heating

The motion induced in a liquid by a heat pulse is mathematically described. The velocity and temperature distributions on the surface and in the body of the liquid are determined numerically. The theoretical results obtained are compared with the experimental data of [1].Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 151–156, September–October, 1987.The authors are very grateful to V. A. Al'vares-Suares for discussing their results.     

Heat and mass transport in nonisothermal turbulent flow when there is a screen formed by a gas of a different nature

We obtain a limiting relative law for heat and mass transport when there is a gas screen in a turbulent boundary layer, which makes it possible to take into account the effect of nonisothermal flow on the turbulent heat and mass transport beyond the region where the foreign gas is injected. The theoretical results are compared with experimental data on the intensity of burn-up of a graphite surface in an air flow when helium is injected through a tangential slit. The experimental data were obtained from the diffusion region of the burn-up.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 5, pp. 152–156, September–October, 1971.     

Effect of the Conductance and Thickness of a Conducting Plate on the Signal from a Material–Velocity Inductive Transducer

The perturbation problem of the magnetic field of a constant–current turn located above a conducting plate set into motion by a plane shock wave with a rectangular profile is considered. It is shown that not only the velocity of the plate but also its dynamic conductivity can be determined on the basis of the electromotive force of induction recorded by means of the turn. For the case where the conductance of the plate is known for both the conducting half–space and for a plate whose thickness is comparable with the skin–layer thickness, approximatecalculated dependences for the velocity of the plate are obtained. A comparison with experimental data and the clarification of the calculated dependences allows one to conclude that the approaches proposed can be used for determining the conductance of metals in shock–wave processes.     

Some data of an experimental study of a supersonic twisted jet

Experimental data are presented on the aerodynamics of a supersonic twisted jet with different values of the system parameters. Shadow photographs of the gasdynamic section and profiles of the average characteristics of the jet are obtained. The experimental data on the stagnation temperature and velocity components were analyzed in universal coordinates. The experimental results are compared with a calculation by the method of the equivalent problem of the theory of heat conduction.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 184–186, January–February, 1977.     

Creep of a heat-resistant aluminum alloy in a complex state of stress

The article gives the results of experimental investigations of the creep of heat-resistant aluminum alloy AK4-1 with constant and variable loads, at a temperature of 175 °C and a duration of the tests equal to 100 h. Based on the experimental data, a verification of the theory of creep is adduced, based on the following hypotheses: 1) the change in the volume is elastic; 2) the deviator of the creep rates is proportional to the deviator of the stresses; 3) the intensities of the stresses, of the creep deformations, and their rates are connected by a relationship which does not depend on the type of the state of stress. It should be pointed out that the results of investigation of creep, under a complex state of stress, in carbon, low-alloy, austenitic steels, copper, and certain light alloys, are given in [1–6].Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 2, pp. 83–86, March–April, 1971.     

The comparison of two approaches to numerical modelling of gas-particles turbulent flow and heat transfer in a pipe

The comparison of two theoretical approaches for the numerical investigation of turbulent gas–solid flows with heat transfer in a pipe are presented in this paper. The first approach is based on Eulerian–Eulerian modelling of investigated phenomena, the second one is formulated within the framework of the Eulerian–Lagrangian approach. The verification of numerical models under consideration. Their testing against available experimental data show good prognostic properties of the elaborated theoretical tool for research activities to study new physical fundamentals of turbulent gas-suspended particles flows in pipes and channels.     

Experimental investigation of laminar flow of a liquid with a free surface in triangular-shaped channels

Results are given of an experimental study of laminar flow of a liquid in triangular-shaped open channels with tangential frictional stress at the free surface. Experiments were carried out when the liquid flow in inclined triangular-shaped channels had Reynolds numbers R < 10 and the working range of Reynolds numbers of the approach air stream was R = (1.6–3.6)·10⁴. The data are presented in relative coordinates as a dependence of the hydraulic resistance coefficient of the liquid on the tangential frictional stress at the free surface. It is shown that with an increase of the tangential frictional stress the hydraulic resistance coefficient considerably increases.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 1, pp. 168–170, January–February, 1977.