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1.
A mathematical model of the process of dissolving and dispersion of natural methane hydrates in ocean sediments is proposed.
A condition which must be satisfied on the solution boundary of the hydrates in the region of their stable thermodynamic state
is derived. The calculated solution rates are several centimeters per year. It is shown that the temperature perturbations
initiated by the transition of a gas from the hydrate into the dissolved state are small and the process can be considered
isothermal.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 170–173, January–February,
1999.
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.
G. G. Tsypkin 《Fluid Dynamics》2005,40(1):117-125
The problem of gas recovery in the process of methane hydrate dissociation in a reservoir saturated with gas-hydrate mixture is considered. The mathematical model of hydrate decomposition into gas and water is generalized to include the negative temperature interval and takes ice formation into account. The solution of the problem is represented in the self-similar approximation. It is shown that there exists a transition hydrate decomposition regime in which water and ice are formed simultaneously. A comparative analysis of the recovery is carried out on the basis of relations derived for the masses of recovered gas in different hydrate dissociation regimes. It is shown that an anomalous increase in the recovered gas volumes is observed in the transition hydrate dissociation regime.__________Translated from Izvestiya Rossiiskoi Academii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, 2005, pp. 132–142. Original Russian Text Copyright © 2005 by Tsypkin. 相似文献
3.
G. G. Tsypkin 《Fluid Dynamics》1993,28(2):223-229
The dissociation of gas hydrate coexisting with ice in a low-temperature natural reservoir is investigated. A mathematical model of the process consisting of a generalization of the Stefan problem and containing two unknown moving phase transition boundaries — the hydrate dissociation and ice melting fronts — is constructed. It is shown that in high-permeability reservoirs the velocity of the dissociation surface is higher than that of the ice melting surface. As the permeability decreases, the fronts change places. The problem is solved in the self-similar approximation.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.2, pp. 84–92, March–April, 1993. 相似文献
4.
A set of experimental system to study hydrate dissociation in porous media is built and some experiments on hydrate dissociation
by depressurization are carried out. A mathematical model is developed to simulate the hydrate dissociation by depressurization
in hydrate-bearing porous media. The model can be used to analyze the effects of the flow of multiphase fluids, the kinetic
process and endothermic process of hydrate dissociation, ice-water phase equilibrium, the variation of permeability, convection
and conduction on the hydrate dissociation, and gas and water productions. The numerical results agree well with the experimental
results, which validate our mathematical model. For a 3-D hydrate reservoir of Class 3, the evolutions of pressure, temperature,
and saturations are elucidated and the effects of some main parameters on gas and water rates are analyzed. Numerical results
show that gas can be produced effectively from hydrate reservoir in the first stage of depressurization. Then, methods such
as thermal stimulation or inhibitor injection should be considered due to the energy deficiency of formation energy. The numerical
results for 3-D hydrate reservoir of Class 1 show that the overlying gas hydrate zone can apparently enhance gas rate and
prolong life span of gas reservoir. 相似文献
5.
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
6.
In gas-gashydrate reservoirs the gas is in the free and bound states. The amount of gas bound in the hydrate depends on the thermodynamic conditions. Therefore, when these conditions are varied it is possible for gas to be released from the hydrate in the desorption regime up to total dissociation of the hydrate into gas and water. Below, the problem of extraction of free and bound gas in the desorption regime is considered.Ufa. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 5, pp. 118–125, September–October, 1996. 相似文献
7.
The gasdynamic consequences of the explosion of a meteoroid in a dense atmosphere are studied. The gas motion is simulated
on the basis of a high-accuracy numerical method using adaptive movable networks. Some effects which could not be reproduced
using coarser networks are revealed.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 29–37, January–February,
1998.
The study was carried out with the support of the Russian Foundation for Fundamental Research (project No. 96-01-00448). 相似文献
8.
A linearized equation of the internal waves developing in an ideal stratified gas under the action of potential vortices concentrated
in a vertical cylinder is obtained. The Cauchy problem for the internal wave equation with right side depending on the vortex
intensity is solved by the integral transform method. In the case of a vortex filament the exact solution is found. Approximate
formulas are obtained on the basis of the steady-phase method when the vorticity is exponentially stratified along the vertical.
Expressions for the phase velocity and amplitude of the radial wave traveling away from the cylindrical vortex are found.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 118–123, January–February,
1998.
The work was carried out with the support of the Russian Foundation for Fundamental Research (project No. 96-01-04599). 相似文献
9.
G. G. Tsypkin 《Fluid Dynamics》1991,26(4):564-572
Boundary conditions on the dissociation surface that take the motion of the liquid phase into account are derived. An analytic solution of the problem is obtained for small deviations from the initial state. The integral characteristic of the phase transitions in the extended zone is introduced and represented analytically. It is shown that for high initial values of the hydrate and water saturations the mobility of the liquid phase must be taken into account. For media with high permeability the amount of gas hydrate dissociated in the volume phase transition zone exceeds by several orders the amount of hydrate decomposed in the total dissociation zone.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 105–114, July–August, 1991. 相似文献
10.
L. E. Sternin 《Fluid Dynamics》2000,35(1):123-131
A comparative numerical analysis of the thrust characteristics of axisymmetric jet nozzles designed by various methods is
carried out. “Extremal“ nozzles designed by variational methods in the absence/presence of internal shocks (I), so-called
“truncated“ nozzles with a uniform characteristic (II), and nozzles designed by the method of conjugate circular arcs (III)
are considered. A comparison is carried out for both perfect and real gases (in the latter case the boundary layer gas viscosity
is taken into account). It is shown that extremal nozzles are the most efficient, while truncated nozzles are somewhat less
so. The thrust characteristics of nozzles designed by the method of conjugate circular arcs for both inviscid and viscous
flow are inferior to those of extremal nozzles by 0.7–1%.
Moscow, Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 152–162, January–February,
2000.
The research was carried out with financial support from the Russian Foundation for Basic Research (project No. 99-01-00891). 相似文献
11.
V. I. Grabovskii 《Fluid Dynamics》2000,35(4):525-533
The optimum design of a gas hydrostatic thrust bearing clearance is obtained using the methods of calculus of variations.
The variational problem of determining the clearance shape giving the maximum load capacity is solved for a given external
pressurization and various journal speeds. The structure of the optimum solution is found on the basis of the gas lubrication
approximation with and without constraints on the height of the bearing pad (pocket). The calculation results embrace all
possible values of the parameters. A comparison with optimum liquid bearings is carried out.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 68–78, July–August, 2000.
The work was carried out with support from the Russian Foundation for Basic Research (projects Nos. 99-01-01211 and 96-15-96158). 相似文献
12.
The results of an analytic and numerical investigation of the properties of the high-velocity “tails” of the distribution
function are given for the solution of the BGK model of the kinetic Boltzmann equation for plane Couette flow of a compressible
gas.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 183–190, July–August, 1998.
The work was carried out with financial support from the Russian Foundation for Basic Research (project No. 96-01-00573; grant
in support of leading science schools No. 96-15-9603). 相似文献
13.
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.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 137–150, May–June, 2008. 相似文献
14.
A mathematical model of the supersonic combustion chamber of a hydrogen/air hypersonic ramjet is proposed. The model is developed
on the basis of a “burn-out curve”, that is, the dependence of the combustion efficiency on the longitudinal coordinate and
the design features of the chamber. The burn-out curve, which describes the mixing and burning of hydrogen and air, is assumed
to be known from previous numerical and experimental studies of these processes under supersonic flow conditions. Other physical
and chemical processes which take place in the combustion chamber, such as excitation of internal molecular degrees of freedom,
hydrogen and oxygen dissociation, OH and NO formation, etc., are assumed to be equilibrium.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 146–154, January–February,
1997.
The work was carried out with the support of the Russian Foundation for Fundamental Research (project No. 93-013-17514). 相似文献
15.
V. I. Nosik 《Fluid Dynamics》1994,29(1):133-139
Nonequilibrium dissociation in a mixture of anharmonic oscillators — molecules of a diatomic gas and its atoms — is investigated
with allowance for the temperature gradient in the boundary layer. The effect of VT, VV, and VT′ exchanges on the dissociation
rate is considered, and the nonequilibrium correction to the macroscopic reaction rate, which depends, in particular, on the
temperature gradient and degree of dissociation, is determined.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.1, pp. 171–179, January–February,
1994. 相似文献
16.
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.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 2, pp. 178–187, March–April, 2009. 相似文献
17.
G. N. Dudin 《Fluid Dynamics》2000,35(1):101-107
The flow formed as a result of gas injection through the permeable surface of a triangular plate is investigated in the regime
of strong viscous-inviscid interaction between the hypersonic flow and the laminar boundary layer. The features of the flow
past strongly cooled surfaces with the formation of supercritical and subcritical flow regions in the boundary layer are studied.
The injected gas distribution ensuring the existence of self-similar solutions in the supercritical flow regions is obtained.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 125–133, January–February,
2000.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 96-01-01391). 相似文献
18.
Supersonic perfect gas flow in plane and axisymmetric channels with the same duct contour is studied on the basis of a numerical
solution of the two-dimensional Navier-Stokes and Euler equations. The calculations were carried out at an inlet Mach number
M∞=4 for various Reynolds numbers and “bell-mouth“ half-angles. The effect of these parameters, as well as that of the flow
three-dimensionality, on the flow pattern is demonstrated. In particular, the existence of viscous flow regimes providing
the most effective supersonic flow deceleration and a higher degree of total pressure recovery as compared with the inviscid
flow is established.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 143–152, March–April, 1998.
The study was carried out with the support of the Russian Foundation for Fundamental Research (project No. 95-01-01129a). 相似文献
19.
A new interpretation of the concept of relative phase permeability is given. Relative phase permeabilities are represented
in the form of fourth-rank tensors. It is shown that in the case of anisotropic porous media functions depending not only
on the saturation but also on the anisotropy parameters represented in the form of ratios of the principal values of the absolute
permeability coefficient tensor correspond to the classical representation of the relative phase permeabilities. For a two-phase
flow in anisotropic porous media with orthotropic and transversely-isotropic symmetry a generalized two-term Darcy’s law is
analyzed.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 87–94, March–April, 1998.
The work was carried out with support from the Russian Foundation for Fundamental Research (project No. 96-01-00623). 相似文献
20.
A new method is proposed to produce gas from oceanic gas hydrate reservoir by combining the ocean surface warm water flooding with depressurization which can efficiently utilize the synthetic effects of thermal, salt and depressurization on gas hydrate dissociation. The method has the advantage of high efficiency, low cost and enhanced safety. Based on the proposed conceptual method, the physical and mathematical models are established, in which the effects of the flow of multiphase fluid, the kinetic process of hydrate dissociation, the endothermic process of hydrate dissociation, ice-water phase equilibrium, salt inhibition, dispersion, convection and conduction on the hydrate dissociation and gas and water production are considered. The gas and water rates, formation pressure for the combination method are compared with that of the single depressurization, which is referred to the method in which only depressurization is used. The results show that the combination method can remedy the deficiency of individual producing methods. It has the advantage of longer stable period of high gas rate than the single depressurization. It can also reduce the geologic hazard caused by the formation deformation due to the maintaining of the formation pressure by injected ocean warm water. 相似文献