共查询到20条相似文献,搜索用时 46 毫秒
1.
D. V. Sadin 《Journal of Applied Mechanics and Technical Physics》1999,40(6):1106-1110
One-dimensional plane pulsed joint motion of a gas phase and a disperse phase in the presence of friction of the latter against
the duct walls are studied numerically using the model of a heterogeneous medium. It is established that two qualitatively
different regimes of motion are possible, depending on the initial conditions in a high-pressure chamber and the value of
the friction factor. It is found that the powder exit velocity is self-similar with respect to friction.
Mozhaiskii Military Space Engineering Academy, St. Petersburg 197082. Translated from Prikladnaya Mekhanika i Tekhnicheskaya
Fizika, Vol. 40, No. 6, pp. 122–127, November–December, 1999. 相似文献
2.
S. V. Stebnovskii 《Journal of Applied Mechanics and Technical Physics》1999,40(3):407-411
The evolution of the structure of a medium containing disperse elements (the drops in a weakly viscous fluid, rigid spheres
in glycerin, and air pores in a gel) is studied experimentally in the case where the gradient temperature and the concentration
fields are absent in the system, and the medium is isolated from the influence of an external force field (including gravity
forces). It is shown that these systems are nonequilibrium: if the initial distance between disperse particles is of the order
of their sizes, the particles approach until they come in contact (coagulation) irrespective of the scale of the system.
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 3, pp. 53–58, May–June, 1999. 相似文献
3.
K. N. Volkov 《Journal of Applied Mechanics and Technical Physics》2008,49(3):425-436
The motion and heat and mass transfer of particles of a disperse admixture in nonisothermal jets of a gas and a low-temperature
plasma are simulated with allowance for the migration mechanism of particle motion actuated by the turbophoresis force and
the influence of turbulent fluctuations of the jet flow velocity on heat and mass transfer of the particle. The temperature
distribution inside the particle at each time step is found by solving the equation of unsteady heat conduction. The laws
of scattering of the admixture and the laws of melting and evaporation of an individual particle are studied, depending on
the injection velocity and on the method of particle insertion into the jet flow. The calculated results are compared with
data obtained with ignored influence of turbulent fluctuations on the motion and heat and mass transfer of the disperse phase.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 95–108, May–June, 2008. 相似文献
4.
The flow and heat transfer in a medium near the critical point (second-kind liquid-gas phase transition) in a stationary and
oscillating mass force field is considered in relation to the experiments conducted in microgravity. The conditions of onset
of a mean convective flow and the characteristic nondimensional parameters describing the vibrational and thermo-gravitational
convection in the medium are analyzed. It is shown that even low-frequency and small-amplitude vibrations or steady microaccelerations
can induce appreciable convective flows.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 70–80, May–June, 2000.
This study received financial support from the Russian Foundation for Basic Research (project 97-01-00124). 相似文献
5.
G. S. Aravin P. A. Vlasov Yu. K. Karasevich E. V. Makolkin I. L. Pankrat'eva V. A. Polyanskii 《Fluid Dynamics》1988,23(5):778-783
Probe measurements in a chemically reacting plasma provide information about certain parameters of the medium, for example,
the effective ionization rate [1, 2]. At atmospheric pressure in a low-temperature plasma containing electronegative components
with significant electron affinity (of the order of or greater than 1.5 eV) considerable negative ion concentrating may occur.
The effect of the negative ions on the volt-ampere characteristic (VAC) of the probe when the chemical reactions in the plasma
are assumed to be frozen was investigated in [3, 4]. Here, the VAC is obtained for negative probe potentials with allowance
for ionization and electron attachment reactions whose characteristic lengths are of the order of the dimensions of the region
disturbed by the probe.
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 163–169, September–October, 1988. 相似文献
6.
S. P. Bautin 《Journal of Applied Mechanics and Technical Physics》2009,50(4):576-583
The Kuropatenko model for a multicomponent medium whose components are polytropic gases is considered. It is assumed that,
as x → ±∞, the multicomponent medium is in a homogeneous state with constant gas-dynamic parameters — velocity, pressure,
and temperature. For the traveling wave flows, conditions similar to the Hugoniot conditions are obtained and used to uniquely
determine the flow parameters for x → −∞ from the flow parameters x → +∞ and traveling wave velocity.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 4, pp. 39–47, July–August, 2009. 相似文献
7.
S. A. Boronin 《Fluid Dynamics》2012,47(3):351-363
The classical stability theory for multiphase flows, based on an analysis of one (most unstable) mode, is generalized. A method
for studying an algebraic (non-modal) instability of a disperse medium, which consists in examining the energy of linear combinations
of three-dimensional modes with given wave vectors, is proposed. An algebraic instability of a dusty-gas flow in a plane channel
with a nonuniform particle distribution in the form of two layers arranged symmetrically with respect to the flow axis is
investigated. For all possible values of governing parameters, the optimal disturbances of the disperse flow have zero wavenumber
in the flow direction, which indicates their banded structure (“streaks”). The presence of dispersed particles in the flow
increases the algebraic instability, since the energy of optimal disturbances in the disperse medium exceeds that for the
pure-fluid flow. It is found that for a homogeneous particle distribution the increase in the energy of optimal perturbations
is proportional to the square of the sum of unity and the particle mass concentration and is almost independent of particle
inertia. For a non-uniform distribution of the dispersed phase, the largest increase in the initial energy of disturbances
is achieved in the case when the dust layers are located in the middle between the center line of the flow and the walls. 相似文献
8.
V. A. Petushkov A. N. Mel'sitov 《Journal of Applied Mechanics and Technical Physics》2006,47(1):116-126
The propagation of shock waves in a system consisting of a deformable medium with damage and a two-phase liquid with gas or
vapor bubbles are studied. The nonlinear interaction of the media are modeled taking into account phase transformations in
the liquid and the damage kinetics of the deformable medium.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 1, pp. 139–152, January–February, 2006. 相似文献
9.
S. V. Stebnovskii 《Journal of Applied Mechanics and Technical Physics》1998,39(5):758-761
A class of media whose structure develops into a foam state during pulsed volume stretching because of unrestricted growth
of cavitational bubbles was determined experimentally. Among such media are low-viscosity Newtonian liquids, and disperse
liquid media (emulsions, suspensions, and gels) with a low-viscosity liquid matrix. The results obtained are important for
the development of a generalized rheological model for cavitating media.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 5, pp. 122–125, September–October, 1998. 相似文献
10.
A. V. Skvortsova 《Fluid Dynamics》1988,23(5):684-689
In [1–3] a series of problems of the motion of heat sources at a temperature higher than the melting point of the surrounding
medium was considered. The heat source could be a laser beam or a hot body. Here, the case of a thin wedge heated to a temperature
higher than the melting point of the surrounding medium and moving at a constant velocity is investigated. The velocity is
high enough for the molten layer formed to be thin. The problem is solved by the method of integral relations. The shape of
the molten zone, the drag on the wedge and other flow characteristics of the melt are determined.
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 52–57, September–October, 1988. 相似文献
11.
I. A. Bedarev Yu. A. Gosteev A. V. Fedorov 《Journal of Applied Mechanics and Technical Physics》2007,48(1):17-26
The dynamics of particles of the disperse phase in a turbulent gas flow in planar shock waves sliding along a solid surface
with a trapezoid cavity is examined numerically. Lifting of particles from the cavity walls is calculated in the approximation
of a rarefied gas suspension. It is shown that the intensity of the transient shock wave and the initial positions of particles
have a significant effect on the particle-lifting properties. The height of particle lifting is found to nonmonotonically
depend on the initial streamwise coordinate and shock-wave Mach number. It is shown that zones of aggregation and subtraction
of particles may be formed at the cavity bottom.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 1, pp. 24–34, January–February, 2007. 相似文献
12.
Yu. I. Kapranov 《Journal of Applied Mechanics and Technical Physics》2000,41(2):309-316
The motion of fluids with suspended particles in porous media is considered. A mathematical model for the interaction of a
monodisperse suspension with a porous structure is proposed. Changes in the parameters of the medium and the flow are studied
for equilibrium regimes.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 2, pp. 113–121, March–April, 2000. 相似文献
13.
G. Sh. Boltachev N. B. Volkov V. V. Ivanov S. N. Paranin 《Journal of Applied Mechanics and Technical Physics》2008,49(2):336-339
A model for dynamic compaction of granular medium is proposed for the case in which the external action far exceeds the yield
strength of the material. A radial axisymmetric compaction problem is solved for a granular medium with nanosize structure
in the presence of a rigid rod at the symmetry axis. Simulated data are compared with experimental data on magnetic pulsed
compaction of oxide nanopowders.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 2, pp. 211–215, March–April, 2008. 相似文献
14.
The effects of viscous dissipation on unsteady free convection from an isothermal vertical flat plate in a fluid saturated
porous medium are examined numerically. The Darcy–Brinkman–Forchheimer model is employed to describe the flow field. A new
model of viscous dissipation is used for the Darcy–Brinkman–Forchheimer model of porous media. The simultaneous development
of the momentum and thermal boundary layers are obtained by using a finite difference method. Boundary layer and Boussinesq
approximation have been incorporated. Numerical calculations are carried out for various parameters entering into the problem.
Velocity and temperature profiles as well as local friction factor and local Nusselt number are shown graphically. It is found
that as time approaches infinity, the values of friction factor and heat transfer coefficient approach steady state. 相似文献
15.
The linear stability theory for the Horton–Rogers–Lapwood problem is extended to the case where the porous medium is saturated
by a nanofluid with thermal conductivity and viscosity dependent on the nanoparticle volume fraction. The effects of Brownian
motion and thermophoresis are considered. In conjunction with the Brownian motion, the nanoparticle fraction becomes stratified,
and hence the viscosity and the conductivity are stratified. The nanofluid is assumed to be dilute and this enables the porous
medium to be treated as a weakly heterogeneous medium with variation, in the vertical direction, of conductivity and viscosity.
In turn this allows an approximate analytical solution to be obtained. 相似文献
16.
O. N. Soboleva 《Journal of Applied Mechanics and Technical Physics》2005,46(6):891-900
Equations for the effective coefficients of random permeability fields for fluid flow through a porous medium with log-stable
distributions are derived using the Wilson renormalization group approach. Results of the theoretical modeling are compared
with data of numerical modeling.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 6, pp. 146–158, November–December, 2005. 相似文献
17.
The problem of aerosol aspiration into a thin-walled tube from a calm medium is solved. The dependence of the aspiration coefficient
on the Stokes number and the steady-state settling velocity is investigated. The results obtained are compared with the calculations
[1, 2] and the experimental formula [3].
Kazan’. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 104–109, March–April, 2000.
The work received financial support from the Russian Foundation for Basic Research (project No. 96-01-00111). 相似文献
18.
A macroscopic law of flow of a viscoplastic Schwedoff-Bingham fluid through a porous medium is obtained on the basis of percolation
theory with allowance for viscous and inertial losses. The asymptotics of the flow law are estimated and expressions for determining
the limiting pressure gradient as a function of the microinhomogeneity parameters are given. Satisfactory qualitative agreement
between the theoretical and known experimental data is observed.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 68–73, January–February,
1999. 相似文献
19.
S. V. Stebnovskii 《Journal of Applied Mechanics and Technical Physics》1999,40(4):691-696
A physical model of the experimentally observed coagulation (the mutual approach) of spherical liquid, solid, and gaseous
disperse elements (of diameter of up to1 cm) in polar liquid and viscoelastic thixotropic matrices when the system is completely isolated from the external forces and
the gradient temperature and concentration fields is proposed. It is shown that a weak stress-field gradient is formed in
a polar liquid or viscoelastic matrix in the presence of interphase at the matrix-spherical disperse element interface, i.e.,
when the capillary pressure is negative at the convex boundary of the matrix. If the second disperse particle enters into
this field, the resulting force acts on it in the direction of the first particle, thus ensuring their coagulation over large
time lapses.
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 4, pp. 156–161, July–August, 1999. 相似文献
20.
The natural convection of a gas-particle suspension inside a two-dimensional square region is investigated within the framework
of a two-velocity two-temperature model of the medium with allowance for phase relaxation and particle deposition.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.2, pp. 46–52, March–April, 1994. 相似文献