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1.
The motion and state of soil at the interface with a penetrating rigid projectile is studied by numerical solution of the
problem of a cylindrical projectile which expands and at the same time moves translationally along its axis in soil. The soil
behavior is described using the model of a compressible elastoplastic medium with transition to a plastic state depending
on the pressure in it. It is shown that a thin layer of soil at the interface with the projectile nose should be set in motion
and move together with the projectile without sliding. An analysis is performed of the validity of using the dry friction
law to determine the shear stresses on the projectile surface during penetration. The heat release in the soil layer at the
interface due to internal friction and its possible effect on the penetration are estimated.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 6, pp. 116–127, November–December, 2005. 相似文献
2.
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
3.
A. N. Kozloborodov G. R. Shrager 《Journal of Applied Mechanics and Technical Physics》2008,49(1):64-70
Flow regimes of the polymer mass filling cylindrical variable-section molds are studied by means of the numerical solution
of the problem of a nonlinear viscoplastic fluid flow with a free surface in cylindrical channels of geometrically complicated
shapes. A mathematical formulation of the problem is given, and factors affecting the molding process are analyzed. Numerical
experiments performed in a wide range of problem parameters make it possible not only to elucidate the specific features of
the hydrodynamic behavior of the free surface of the moving polymer mass, but also to establish the existence of two flow
regimes depending on the ratio of the generalized Reynolds number to the Froude number.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 1, pp. 81–88, January–February, 2008. 相似文献
4.
S. A. Sazhenkov 《Journal of Applied Mechanics and Technical Physics》2008,49(4):587-597
The Cauchy problem for the Darcy-Stefan model, which describes the process of freezing (thawing) of a saturated porous soil
with allowance for liquid-phase filtration, is considered. The model includes the Darcy law, the equation of liquid-phase
incompressibility, the equation of absence of solid-phase motion, the equation of energy balance in the porous soil-saturating
continuous medium system, and also the Stefan condition and the condition of continuity of the normal components of the velocity
field at the interface boundary. The existence of generalized solutions of the problem satisfying an additional condition
of entropy nondecreasing in a thermomechanical system (i.e., the second law of thermodynamics) is proved by the method of
the kinetic equation.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 4, pp. 81–93, July–August, 2008. 相似文献
5.
S. V. Osipov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):781-788
This paper is concerned with mathematical modeling and solution of the problem of the collapse of a spherical cavity in a
viscoelastic medium under the action of constant pressure at infinity. A differential equation of motion for the cavity boundary
is constructed and solved numerically. The existence of three modes of motion of the boundary is established, and a map of
these modes in the plane of the determining parameters is constructed. Asymptotic forms of the solutions of the problem for
all modes are constructed. The problem of cavity collapse with capillary forces taken into account is formulated and solved.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 93–101, September–October, 2008. 相似文献
6.
The influence of high-frequency horizontal vibrations on convection in the Hele-Shaw cell located in a uniform gravity field
is considered experimentally and theoretically. Nonlinear regimes of vibrational convection in the supercritical region are
examined. It is shown that horizontal vibrations (directed toward the wide sides of the cell) decrease the threshold of quasi-equilibrium
stability. Regions of existence of one- and two-vortex steady flows are found, and unsteady regular and random regimes of
thermal vibrational convection are considered. New random regimes in the Hele-Shaw cell are found, which result from nonlinear
interaction of the “lower” modes responsible for the formation of regular supercritical convective regimes.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 2, pp. 40–48, March–April, 2006. 相似文献
7.
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
8.
Attention is drawn to the pressure increase in the pores of a carbon-carbon composite oxidizing in air at high temperatures.
Estimates are obtained for the relative pressure difference between the coating-substrate interface and the outer medium in
two limiting cases: for hydrodynamic and free-molecule flow regimes in the pores. The effect of the coating thickness, the
ambient pressure and the temperature of the material on the relative pressure difference is investigated.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 144–149, July–August, 1994. 相似文献
9.
S. P. Bautin 《Journal of Applied Mechanics and Technical Physics》2008,49(3):375-382
The Kuropatenko model is considered, as applied to a multicomponent medium where the number of the sought functions coincides
with the number of equations. The velocities of sound in a multicomponent medium at rest are determined. A formula of a polynomial
of power N whose positive roots are squared velocities of sound in a medium with N components is derived. For N = 2, the values
of two velocities of sound are determined in explicit form. It is demonstrated that the thus-found maximum value of the velocity
of sound in a two-component medium containing nitrogen and oxygen with volume concentrations corresponding to air differs
(in dimensionless form) from the velocity of sound in air by less than 0.3%. Numerical calculations predict the existence
of three velocities of sound in a three-component medium. If the velocity of sound in all N components is identical, it is
proved that the maximum velocity of sound in such a medium equals this velocity, and there is only one more velocity of sound
in the medium, which has a lower value.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 35–44, May–June, 2008. 相似文献
10.
V. Sh. Shagapov M. K. Khasanov N. G. Musakaev 《Journal of Applied Mechanics and Technical Physics》2008,49(3):462-472
Specific features of formation of gas hydrates due to injection of a gas into a porous medium initially filled by a gas and
water are considered. Self-similar solutions of an axisymmetric problem, which describe the distributions of the basic parameters
in the reservoir, are constructed. The existence of solutions is demonstrated, which predict gas hydrate formation both on
the frontal surface and in the volume zone.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 137–150, May–June, 2008. 相似文献
11.
V. A. Batishchev 《Journal of Applied Mechanics and Technical Physics》1999,40(3):479-484
Thermocapillary flows of a fluid in a lamina with a rigid lower wall and a free upper surface, along which the temperature
gradient is given in the radial direction, are investigated for large Marangoni numbers. Self-similar solutions which describe
the axisymmetric flow regimes of a fluid without the circumferential velocity component are constructed numerically and asymptotically
for a system of Prandtl equations. It is shown that a pair of new self-similar flow regimes of a fluid with rotation branches
off from the regimes obtained. The new regimes ere calculated numerically and asymptotically.
Rostov State University, Rostov-on-Don 344090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No.
3, pp. 137–142, May–June, 1999. 相似文献
12.
M. M. Khasanov 《Fluid Dynamics》1994,29(2):208-213
The stability of the steady-state flow regimes of a liquid with dissolved gas in a porous medium is investigated in the region
of the saturation pressure. It is shown that under certain conditions periodic and stochastic self-oscillations caused by
the accumulation in the porous medium and subsequent entrainment of the very small gas bubbles formed as a result of pressure
reduction may arise. Experimental data that confirmed the theoretical results are presented.
Ufa. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 66–73, March–April, 1994. 相似文献
13.
V. G. Bazhenov A. M. Bragov V. L. Kotov S. V. Zefirov A. V. Kochetkov S. V. Krylov A. K. Lomunov 《Journal of Applied Mechanics and Technical Physics》2000,41(3):519-525
Results of an experimental and theoretical analysis of Kol'skii's method for dynamic tests of soft soils in an elastic casing
are presented. The model proposed by S. S. Grigoryan for a plastically compressible medium with parameters determined in shock-wave
experiments was used as the model of a soft soil. The high-rate deformation of the soil was simulated using a modified “Dunamics-2”
program package. The numerical calculations performed showed that the compliance of the casing and friction practically do
not influence the measured characteristics of the soil and the basic premises of Kol'skii's method are adequate for soft soil
too.
Institute of Mechanics, Nizhinii Novgorod State University, Nizhnii Novgorod 603600. Translated from Prikladnaya Mekhanika
i Tekhnicheskaya Fizika, Vol. 41, No. 3, pp. 155–162, May–June, 2000. 相似文献
14.
L. V. Baev 《Journal of Applied Mechanics and Technical Physics》2009,50(4):691-697
A problem of propagation of longitudinal and transverse waves in a multimodulus elastic isotropic medium is considered. In
the model used, the medium is described by a potential depending on three invariants of strains, which allows the influence
of preliminary deformation of the medium on the longitudinal and transverse velocities to be taken into account.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 4, pp. 176–182, July–August, 2009. 相似文献
15.
Numerical simulation of the separation flow on the lateral surface of an aircraft due to interaction between the engine exhaust
plume and the external air-stream is carried out on the basis of the full Navier-Stokes equations. Three separated flow regimes
are revealed, namely, closed, open and periodic. The conditions under which each of these three regimes may exist are determined.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.1, pp. 132–138, January–February,
1994. 相似文献
16.
G. V. Kuznetsov M. A. Sheremet 《Journal of Applied Mechanics and Technical Physics》2008,49(6):946-956
Conjugate convective-conductive heat transfer in a rectangular region with forced flow and a heat source is simulated numerically.
Distributions of the thermal and hydrodynamic characteristics of the flow regimes studied are obtained. The evolution of the
process analyzed is shown.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 69–81, November–December, 2008 相似文献
17.
Models of the residual oil saturation distribution are proposed for linear, axisymmetric, and general flows. The steady displacing
fluid flow model makes it possible to find equilibrium residual oil saturation distributions corresponding to given flow regimes
by treating the porous medium with capillary-trapped oil as a medium with permeability that depends on the displacement conditions.
The dynamics of the mobilized globules of the residual oil are excluded from consideration. The simulation results indicate
that the residual oil saturation distribution after stimulation of the wash-out zone by means of enhanced oil recovery techniques
is generally essentially nonuniform.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 98–104, May–June, 2000. 相似文献
18.
M. Yu. Plotnikov 《Journal of Applied Mechanics and Technical Physics》2008,49(3):400-406
A supersonic flow around a cylinder is studied by the direct statistical Monte Carlo method in a wide range of rarefaction:
from regimes close to continuum to free-molecular flow. The effect of the accommodation coefficient on the flow near the cylinder
and on heat transfer between the gas and the cylinder is examined.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 64–72, May–June, 2008. 相似文献
19.
E. V. Proskuryakov M. V. Sorokin V. M. Fomin 《Journal of Applied Mechanics and Technical Physics》2008,49(6):899-901
Interaction of a shaped-charge jet with a target possessing an axial orifice is studied experimentally. For an orifice diameter
approximately equal to 0.2D, where D is the shaped-charge diameter, the shaped-charge penetration depth is found to be substantially reduced owing to
deviation of the shaped-charge jet axis from the shaped charge axis because of imperfections of the manufacturing technology.
A diameter of the target orifice providing unconstrained penetration of the shaped-charge jet is determined.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 6, pp. 13–16, November–December, 2008. 相似文献
20.
A linear and nonlinear analysis of the distributed oscillations of an elastic tube with a fluid flowing in it is developed.
The critical flow velocity and the wavelength and oscillation frequency in the tube-flow system at loss of stability are found.
The geometrical and physical nonlinearities, the latter related to increase in the Young’s modulus of the tube wall material
with increasing strain, are considered. It is shown that four characteristic regimes of change of tube shape are possible:
local dilatation, collapse, flexure, and distributed auto-oscillations. The tube oscillations are analyzed numerically for
the nonaxisymmetric case. The conditions of existence of these effects in blood vessels are examined.
Nizhni Novgorod, e-mail: klochkov@appl.sci-nnov.ru. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti
i Gaza, No. 4, pp. 46–55, July–August, 2000.
The work was supported by the Russian Foundation for Basic Research (project No. 97-02-18612). 相似文献