共查询到20条相似文献,搜索用时 31 毫秒
1.
G. G. Tsypkin 《Fluid Dynamics》1998,33(1):82-90
The process of dissociation of gas hydrates coexisting with gas and ice in low-temperature reservoirs is considered. A qualitative
analysis of the phase transitions which enables possible configurations of the solutions to be predicted is carried out on
the basis of the phase diagram for methane hydrate. Mathematical models of hydrate decomposition in reservoirs which take
into account the formation of an extended dissociation zone and the presence of two phase transition fronts are proposed.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 101–111, January–February,
1998.
The work was carried out with financial support from the Russian Foundation for Fundamental Research (project No. 96-01-00521). 相似文献
2.
S. V. Khabirov 《Journal of Applied Mechanics and Technical Physics》2007,48(5):641-648
All partially invariant solutions in terms of the group of extensions for a model of radial motions of an ideal gas are found.
The solutions are obtained by the method of separation of variables in an equation containing functions of one variable but
different functions of different independent variables. The solutions predict different continuous unsteady convergence or
expansion of the gas under the action of a piston with a point sink or source. If the sink or source affects all particles
simultaneously, a collapse or an explosion occurs.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 5, pp. 26–34, September–October, 2007. 相似文献
3.
We study the boundary-layer approximation of the classical mathematical model that describes the discharge of a laminar hot
gas in a stagnant colder atmosphere of the same gas. We prove the existence and uniqueness of solutions to a nondegenerate
problem (without zones of stagnation of gas temperature or velocity). The asymptotic behavior of these solutions is also studied
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 4, pp. 192–205, July–August, 2008. 相似文献
4.
A thin liquid sheet present in the shear layer of a compressible gas jet is investigated using an Eulerian approach with mixed-fluid
treatment for the governing equations describing the gas–liquid two-phase flow system, where the gas is treated as fully compressible
and the liquid as incompressible. The effects of different topological configurations, surface tension, gas pressure and liquid
sheet thickness on the flow development of the gas–liquid two-phase flow system have been examined by direct solution of the
compressible Navier–Stokes equations using highly accurate numerical schemes. The interface dynamics are captured using volume
of fluid and continuum surface force models. The simulations show that the dispersion of the liquid sheet is dominated by
vortical structures formed at the jet shear layer due to the Kelvin–Helmholtz instability. The axisymmetric case is less vortical
than its planar counterpart that exhibits formation of larger vortical structures and larger liquid dispersion. It has been
identified that the vorticity development and the liquid dispersion in a planar configuration are increased at the absence
of surface tension, which when present, tends to oppose the development of the Kelvin–Helmholtz instability. An opposite trend
was observed for an axisymmetric configuration where surface tension tends to promote the development of vorticity. An increase
in vorticity development and liquid dispersion was observed for increased liquid sheet thickness, while a decreasing trend
was observed for higher gas pressure. Therefore surface tension, liquid sheet thickness and gas pressure factors all affect
the flow vorticity which consequently affects the dispersion of the liquid.
相似文献
5.
A. N. Golubyatnikov 《Fluid Dynamics》1998,33(4):612-617
Within the framework of the Newtonian mechanics, we studied the possibility of the formation of a uniformly expanding gravitating
gas due to the passage of a detonation wave through a freely compressible medium (dust). The formulation of the problem is
associated with the modeling of the large-scale expansion of the Universe. At the same time, the results obtained can also
be applied to the calculation of the consequences of the spherical collapse of other gaseous masses. A class of exact solutions
taking the pressure gradient into account is derived. Possible changes in the system behavior, as compared to with case of
uniform pressure studied in [1], are analyzed.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 176–182, July–August, 1998.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 97-01-00196). 相似文献
6.
D. V. Parshin A. P. Chupakhin 《Journal of Applied Mechanics and Technical Physics》2006,47(6):773-784
The nonbarochronic regular partially invariant submodel of the equations of gas dynamics is studied. The submodel reduces
to an implicit ordinary differential equation of the first order for an auxiliary function X = X(x). The physical quantities
(velocity, density, and pressure) are expressed in terms of the function X. The properties of the solutions of the equation
are investigated and interpreted physically in terms of gas motion. The existence of a shock-wave solution is proved. The
properties of the shock adiabat are studied. It is shown that the results obtained are new and differ significantly from the
results for the case of no constant force.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 6, pp. 3–16, November–December, 2006. 相似文献
7.
V. V. Bublik 《Journal of Applied Mechanics and Technical Physics》2006,47(6):790-799
A system of the Navier-Stokes equations of two-dimensional motion of a viscous heat-conducting perfect gas with a polytropic
equation of state is considered. Regular, partially invariant solutions of rank 1 and defect 1 are studied. A sufficient condition
of their reducibility to invariant solutions of rank 1 is proved. All solutions of this class with a linear dependence of
the velocity-vector components on spatial coordinates are examined. New examples of solutions that are not reducible to invariant
solutions are obtained.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 6, pp. 23–33, November–December, 2006. 相似文献
8.
The problem of peripheral explosion in a star initially at equilibrium is solved for an exponential density distribution.
Qualitatively new flow modes, such as recurrent ejection of the star shell and partial scatter of its matter in interstellar
space, are obtained. The critical energies corresponding to various flow modes are determined. Calculations conducted over
a wide range of the determining parameters allow certain conclusions to be drawn concerning the possibility of explaining
the phenomena occurring in the interior of pulsing and variable stars.
The problem of dynamic explosion of star equilibrium, followed by the formation of a detonation wave travelling through a
gravitating gas at rest, is also considered. It is shown that various solutions involving detonation may be constructed by
choosing the adiabatic exponent and the exponent of the power density distribution.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 157–163, May–June, 1998. 相似文献
9.
O. V. Voinov 《Journal of Applied Mechanics and Technical Physics》2007,48(3):385-392
The motion of thin films of a viscous incompressible liquid in a gas under the action of capillary forces is studied. The
surface tension depends on the surfactant concentration, and the liquid is nonvolatile. The motion is described by the well-known
model of quasi-steady-state viscous film flow. The linear-wave solutions are compared with the solution using the Navier-Stokes
equations. Situations are studied where a solution close to the inviscid two-dimensional solutions exists and in the case
of long wavelength, the occurrence of sound waves in the film due to the Gibbs surface elasticity is possible. The behavior
of the exact solutions near the region of applicability of asymptotic equations is studied, and nonmonotonic dependences of
the wave characteristics on wavenumber are obtained.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 3, pp. 103–111, May–June, 2007. 相似文献
10.
V. V. Bublik 《Journal of Applied Mechanics and Technical Physics》1999,40(5):820-823
All invariant solutions of rank 1 of the two-dimensional equations of motion of a heat-conducting perfect gas with a polytropic
equation of state are described. A sufficient condition for reducibility of regular, partially invariant solutions of rank
1 and defect 1 to invariant solutions is given.
Institute of Theoretical and Applied Mechanics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated
from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 5, pp. 51–54, September–October, 1999. 相似文献
11.
L. V. Ovsyannikov 《Journal of Applied Mechanics and Technical Physics》2000,41(5):865-869
It is shown that a periodic two-dimensional isentropic motion of a gas exists and it is described by an exact solution of
the equations of gas dynamics. A polytropic gas that fills a circular cylinder rotates and oscillates (in the radial direction)
simultaneously under the action of periodically changing external pressure. The solution obtained belongs to the class of
solutions with a velocity field that is linear in the coordinates (with homogeneous deformation).
Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 5, pp. 115–119, September–October, 2000. 相似文献
12.
Self-similar problem of decomposition of gas hydrates in a porous medium upon depression and heating
R. I. Nigmatulin V. Sh. Shagapov V. R. Syrtlanov 《Journal of Applied Mechanics and Technical Physics》1998,39(3):421-427
We consider the specifics of decomposition of gas hydrates under thermal and depressive action on a porous medium completely
filled with a solid hydrate in the initial condition. The existence of volumetric-expansion zones, in which the hydrate coexists
in equilibrium with water and gas, is shown to be possible in high-permeable porous media. The self-similar problems of hydrate
decomposition upon depression and heating are studied. Ii is shown that there are solutions according to which hydrate decomposition
can occur both on the surface of phase transitions and in the volumetric region. We note that, in the first case, decomposition
is possible without heat supply to a medium and even with heat removal.
Institute of Mechanics of Multiphase Systems, Siberian Division, Russian Academy of Sciences, Tyumen' 625000. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 3, pp. 111–118, May–June, 1998. 相似文献
13.
The high-speed combustible gas ignited by a hot gas jet, which is induced by shock focusing, was experimentally investigated. By use of the separation mode of shock tube, the test section of a single shock tube is split into two parts, which provide the high-speed flow of combustible gas and pilot flame of hot gas jet, respectively. In the interface of two parts of test sections the flame of jet was formed and spread to the high-speed combustible gas. Two kinds of the ignitions, 3-D “line-flame ignition” and 2-D “plane-flame ignition”, were investigated. In the condition of 3-D “line-flame ignition” of combustion, thicker hot gas jet than pure air jet, was observed in schlieren photos. In the condition of 2-D “plane-flame ignition” of combustion, the delay time of ignition and the angle of flame front in schlieren photos were measured, from which the velocity of flame propagation in the high-speed combustible gas is estimated in the range of 30–90m/s and the delay time of ignition is estimated in the range of 0.12–0.29ms.
PACS 47.40.Nm; 82.40.FpPart of this paper was presented at the 5th International Workshop on Shock/Vortex Interaction, Kaohsiung, October 27–31, 2003. 相似文献
14.
V. E. Dontsov V. E. Nakoryakov E. V. Dontsov 《Journal of Applied Mechanics and Technical Physics》2009,50(2):318-326
The processes of dissolution and hydrate formation behind a moderate-amplitude shock wave in water containing gas bubbles
(mixture of nitrogen and carbon dioxide) are studied in experiments with different initial static pressures in the medium
and concentrations of carbon dioxide in bubbles. An increase in static pressure in the gas-liquid medium is demonstrated to
enhance the influence of the non-reacting gas (nitrogen) on the processes of dissolution and hydrate formation.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 178–187, March–April, 2009. 相似文献
15.
V. M. Teshukov 《Journal of Applied Mechanics and Technical Physics》1998,39(1):12-23
An approximate system of equations that describe unsteady flow of an inviscid non-heat-conducting gas in a narrow channel
of varying area is derived. Generalized characteristics and hyperbolicity conditions are obtained for this system of equations.
In connection with characteristics theory, the average Mach number and the flow criticality condition are introduced. Exact
solutions that describe steady transonic channel flows are investigated.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 1, pp. 15–27, January–February, 1998. 相似文献
16.
M. N. Kogan 《Fluid Dynamics》1988,23(5):768-774
In order to describe the motion of a selectively excited gas, model kinetic equations are proposed in the present study, and
they are used to construct the equations of gas dynamics. There is consideration of the one-dimensional problem of heat transmission
between plates across a selectively excited gas. Discontinuities are found in the temperature on the boundaries of the phases.
It is shown that a selectively excited gas may be used to transmit heat from a cold body to a hot one.
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 151–158, September–October, 1988. 相似文献
17.
Weakly nonlinear stability analysis of a falling film with countercurrent gas–liquid flow has been investigated. A normal
mode approach and the method of multiple scales are employed to carry out the linear and nonlinear stability solutions for
the film flow system. The results show that both supercritical stability and subcritical instability are possible for a film
flow system when the gas flows in the countercurrent direction. The stability characteristics of the film flow system are
strongly influenced by the effects of interfacial shear stress when the gas flows in the countercurrent direction. The effect
of countercurrent gas flow in a falling film is to stabilize the film flow system. 相似文献
18.
Yu. N. Gordeev A. E. Sandakov Yu. L. Chizhov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):776-780
A problem of piston-induced displacement of one gas by another in cracks (porous media) in an axisymmetric case with a quadratic
drag law is studied. Self-similar solutions for determining the dynamic characteristics (velocity and pressure) of the displacing
and displaced gases are constructed in quadratures. The velocity and pressure are studied as functions of a self-similar variable
for several initial conditions and parameters.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 87–92, September–October, 2008. 相似文献
19.
V. N. Makarov 《Journal of Applied Mechanics and Technical Physics》1999,40(4):581-587
The problems of developing a kinetic model of a medium (gas and plasma) are considered from the viewpoint of choice of the
most important physicochemical processes. For the problem of a direct shock wave propagating in the atmosphere, kinetic models
are selected with allowance for the error in specifying reaction-rate constants. The investigation was performed using an
automated system that incorporates structured bases of physicochemical data, a generator of kinetic equations, a complex of
programs for direct calculation, and program modules for determining, from a set of admissible solutions, the one satisfying
specified criteria.
Institute of Mechanics, Moscow State University, Moscow 119899. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika,
Vol. 40, No. 4, pp. 36–43, July–August, 1999. 相似文献
20.
B. N. Elemesova 《Journal of Applied Mechanics and Technical Physics》1999,40(1):28-35
The plane-parallel unsteady-state shear gas flow in a narrow channel of constant cross section is considered. The existence
theorem of solutions in the form of simple waves of a set of equations of motion is proved for a class of isentropic flows
with a monotone velocity profile over the channel depth. The exact solution described by incomplete beta-functions is found
for a polytropic equation of state in a class of isentropic flows.
Lavrent'ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 1, pp. 36–43, January–February, 1999. 相似文献