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1.
B. F. Boyarshinov 《Journal of Applied Mechanics and Technical Physics》2000,41(4):686-691
It is shown that, for a certain proportion between the rib height (2–15 mm) installed at the test-section entrance and the turbulence level of the main flow (1–26%), there are extrema of parameters that describe mass transfer on the surface of an evaporating liquid fuel. In tests with
and without combustion, discrete changes in the rates of heat and mass transfer are observed. Conditions for their manifestation
are analyzed.
Kutateladze Institute of Thermal Physics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskava Fizika, Vol. 41, No.4, pp. 124–130, July–August, 2000. 相似文献
2.
V. I. Pinakov 《Journal of Applied Mechanics and Technical Physics》2008,49(5):883-890
The method chosen to compensate for the forces acting on the barrel in the course of compression and confinement of the test
gas in the settling chamber of a hypersonic wind tunnel with a free locking piston is justified. A method is proposed to compensate
for the effect of adverse factors by optimizing the mass of an auxiliary piston introduced into the system. The effectiveness
of the method is validated experimentally. As a result, for the case of gas compression to 200 MPa, the displacement of the center of mass of the barrel is reduced from 50 to 0.25 mm, which is smaller than the amplitude of elastic axial extension corresponding to the maximum pressure of the gas.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 212–220, September–October, 2008. 相似文献
3.
Herv�� V. J. Le Meur 《Journal of Mathematical Fluid Mechanics》2011,13(4):481-514
In this article, we prove the local well-posedness, for arbitrary initial data with certain regularity assumptions, of the
equations of a Viscoelastic Fluid of Johnson–Segalman type in a domain with a free surface. Managing more general constitutive
laws is also briefly depicted. The 2D geometry is defined by a solid fixed bottom and an upper free boundary submitted to
surface tension. The proof relies on a Lagrangian formulation. First we solve two intermediate problems through a fixed point
using mainly (Allain in Appl Math Optim 16:37–50, 1987) for the Navier–Stokes part. Then we solve the whole Lagrangian problem
on [0, T
0] for T
0 small enough through a contraction mapping. Since the Lagrangian solution is regular enough and the change of coordinates
invertible, we can come back to an Eulerian one. 相似文献
4.
V. É. Distanov A. G. Kirdyashkin 《Journal of Applied Mechanics and Technical Physics》2000,41(3):498-503
The effect of the height of a melted layer on its thermal structure is examined. The maximum velocities of ascending and descending
flows during crystal growth by the Stockbarger method with the use of the accelerated crucible rotation technique in crucibles100 mm in diameter at Taylor numbersTa>10
8 are estimated. A sudden increase in the amplitude of temperature oscillations with diminution of the height of the melted
layer caused by unsteady rotation of the crucible is found. With decreasing height of the melted layer, the velocity of both
ascending and descending flows at the axis of a cylindrical ampoule decreases.
Institute of Mineralogy and Petrography, Siberian Division. Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 3, pp. 133–138, May–June, 2000. 相似文献
5.
V. Ya. Ternovoi K. V. Khishchenko A. A. Charakhch’yan 《Journal of Applied Mechanics and Technical Physics》2009,50(3):371-379
This paper considers the interaction between an absolutely rigid wall or a steel plate and the rarefaction wave arising in
solid deuterium when a 30–150 GPa shock wave arrives at the free surface. It is shown that, in the entropy trace near the wall or interface with the plate,
a high-temperature plasma arises, in which a thermonuclear fusion is possible, at least, for shock-wave pressures above 70 GPa. The dimension of the plasma region and the time of its establishment are proportional to the distance between the free surface
and the wall. Estimates of the proportionality coefficients are given. It is noted that, in this case, unlike in other methods
of high-temperature plasma generation, the time of existence of the plasma may not depend on the sound velocity in it. It
is shown that, by using a conical solid-state target wit an exit hole, the shock-wave pressure in solid deuterium can be increased
from 10 to 100 GPa.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 15–24, May–June, 2009. 相似文献
6.
7.
The effect of the impact velocity and shape of the head of a rigid shell of caliber 20mm on the depth of its penetration into a thick obstacle made of mild low-carbon steel for impact velocities of up to 600m/sec is studied experimentally. Experimental relations between the penetration depth and the impact velocity are obtained for
shells with conical and semispherical heads. It is found that for a penetration depth equal to 1 or 2 calibers, the penetration
resistance does not depend on the head shape and is characterized by an average stress equal to 2.98GPa.
Institute of Experimental Physics, Sarov 607190. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No.
1, pp. 38–40, January–February, 2000. 相似文献
8.
Experiments were performed to study the strength of water under conditions of pulsed extension, which is typical of the interaction
between a triangular compression pulse and a free surface. The tests were performed in a wide (40–1000 MPa) range of rariation
in the amplitude of the compression pulse at deformation rates of 104−105 sec−1. It is found that as the compression-pulse amplitude increases from 150 to 1050 MPa, the strength of water decreases from
46 to 22 MPa. The deformation rate was found to have little effect on the strength. The possibility of using the model of
homogenous nucleation (formation of cavitation nuclei) to interpret the data obtained is discussed.
Institute of Chemical Physical, Russian Academy of Sciences, Chernogolovka 142432. Translated from Prikladmaya Mekhanika i
Tekhnicheskaya Fizika, Vol. 41, No. 4, pp. 198–205, July–August, 2000. 相似文献
9.
D. A. Nield 《Transport in Porous Media》2011,88(2):187-191
The singular behavior of the Horton–Rogers–Lapwood problem when a Newtonian fluid is replaced by a standard power-law fluid
is investigated further. Using weakly nonlinear stability theory, an estimate is made of the amplitude of convection at which
the convection is initiated (in the case of a fluid with index n > 1) or levels off (in the case of a fluid with n < 1). 相似文献
10.
V. A. Gaponov 《Journal of Applied Mechanics and Technical Physics》1999,40(4):622-629
The hydrodynamic and heat-transfer processes in the problem of a laminar thermocapillary flow of a viscous incompressible
fluid in a square cavity with isothermal vertical and isentropic horizontal surfaces are investigated numerically under the
assumption that the gravity is absent, the free surface is flat, and the surface tension depends linearly on the temperature.
Calculations were performed by a compact-difference method on irregular grids with a fifth-order accuracy for four Prandtl
numbers (Pr=1, 16, 200, and 3000) as the Marangoni (Ma) number varies from 102 to 104. The maximum local heat transfer versus theMa number is obtained. It is shown that, for thePr values considered, the maxima of the distribution of the horizontal velocity component on the surface is displaced to the
cold boundary according to a law inversely proportional to theMa number.
Kutateladze Institute of Thermal Physics, Siberian Division, Russian Academy of Sciences, Siberian Division, Russian Academy
of Sciences, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 4, pp. 81–89,
July–August, 1999. 相似文献
11.
A. P. Alkhimov A. I. Gudilov V. F. Kosarev N. I. Nesterovich 《Journal of Applied Mechanics and Technical Physics》2000,41(1):188-192
Based on experimental data and numerical modeling, it is shown that a lamina of melted metal of thickness of order0.01 d, in which the temperature is close to the melting point of the particle material, can be formed upon high-speed impact
(v
0≈500–1200 m/sec) of a fine metal particle (d=1–50 μm) on a rigid undeformable barrier near the contact surface.
Institute of Theoretical and Applied Mechanics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated
from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 1, pp. 204–209, January–February, 2000. 相似文献
12.
Yu. Ya. Trifonov 《Journal of Applied Mechanics and Technical Physics》2007,48(1):91-100
The linear and nonlinear stability of downward viscous film flows on a corrugated surface to freesurface perturbations is
analyzed theoretically. The study is performed with the use of an integral approach in ranges of parameters where the calculated
results and the corresponding solutions of Navier-Stokes equations (downward wavy flow on a smooth wall and waveless flow
along a corrugated surface) are in good agreement. It is demonstrated that, for moderate Reynolds numbers, there is a range
of corrugation parameters (amplitude and period) where all linear perturbations of the free surface decay. For high Reynolds
numbers, the waveless downward flow is unstable. Various nonlinear wavy regimes induced by varying the corrugation amplitude
are determined.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 1, pp. 110–120, January–February, 2007. 相似文献
13.
14.
Regimes of superfluid-helium boiling on structural-steel spheres 4.8 and 6.0 mm in diameter, with heaters installed inside, are examined. Experimental data on the evolution of vapor films formed on the
spherical surfaces are obtained.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 6, pp. 78–84, November–December, 2006. 相似文献
15.
Experimental study of evolution of disturbances in a supersonic boundary layer on a swept-wing model under controlled conditions 总被引:1,自引:0,他引:1
A. D. Kosinov N. V. Semionov Yu. G. Ermolaev V. Ya. Levchenko 《Journal of Applied Mechanics and Technical Physics》2000,41(1):44-49
Experimental data on stability of a three-dimensional supersonic boundary layer on a swept wing are presented. Evolution of
artificial wave trains was studied. The experiments were conducted for Mach numberM=2.0 and unit Reynolds numberRe
1=6.6·106m−1 on a swept-wing model with a lenticular profile and a40° sweep angle of the leading edge at zero incidence. Excitation of high-frequency disturbances caused by secondary-flow instability
at a high initial amplitude was observed. It is shown that the evolution of disturbances at frequencies of10, 20, and30 kHz is similar to the development of travelling waves for the case of subsonic velocities.
Institute of Theoretical and Applied Mechanics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated
from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 41, No. 1, pp. 50–56, January–February, 2000. 相似文献
16.
A. A. Vasil’ev V. N. Rychkov M. E. Topchiyan 《Journal of Applied Mechanics and Technical Physics》2007,48(3):361-367
The laminar-turbulent transition is experimentally studied in boundary-layer flows on cones with a rectangular axisymmetric
step in the base part of the cone and without the step. The experiments are performed in an A-1 two-step piston-driven gas-dynamic
facility with adiabatic compression of the working gas with Mach numbers at the nozzle exit M
∞ = 12–14 and pressures in the settling chamber P0 = 60–600 MPa. These values of parameters allow obtaining Reynolds numbers per meter near the cone surface equal to Re
1e = (53–200) · 106
m
−1. The transition occurs at Reynolds numbers Re
tr
= (2.3–5.7) · 106.
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Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 48, No. 3, pp. 76–83, May–June, 2007. 相似文献
17.
The mixed convection in a horizontal fluid layer which is generated by uniform heating from below and by rotation of one of
the boundaries of the layer was studied experimentally. The region occupied by the fluid is a cylinder of radius320 mm and height45 mm. Either the upper or the lower boundary together with the side wall rotates. For Rayleigh numbersRa≃2·10
7, in a broad range of Reynolds numbers, based on experimental data we constructed mean-temperature profiles along the normal
to the upper boundary and with a uniform step over the radius. In addition, we obtained data on the radial thermal stratification
of the fluid, the integral flow through the fluid layer, and information on temperature fluctuations. The complicated character
of the dependence of the heat transfer on the Reynolds number was shown. The obtained dependences of the heat transfer and
temperature inhomogeneity on Reynolds numbers was explained qualitatively.
Kutateladze Institute of Thermal Physics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from
Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 3, pp. 126–133, May–June, 1998. 相似文献
18.
We study an eigenvalue problem associated with a reaction-diffusion-advection equation of the KPP type in a cellular flow.
We obtain upper and lower bounds on the eigenvalues in the regime of a large flow amplitude A ≪ 1. It follows that the minimal pulsating traveling front speed c
*(A) satisfies the upper and lower bounds C
1
A
1/4≦ c
*(A)≦ C
2
A
1/4. Physically, the speed enhancement is related to the boundary layer structure of the associated eigenfunction – accordingly,
we establish an “averaging along the streamlines” principle for the unique positive eigenfunction. 相似文献
19.
The boundary layer problem of a power-law fluid flow with fluid injection on a wedge whose surface is moving with a constant
velocity in the opposite direction to that of the uniform mainstream is analyzed. The free stream velocity, the injection
velocity at the surface, moving velocity of the wedge surface, the wedge angle and the power law index of non-Newtonian fluid
are assumed variables. The fourth order Runge–Kutta method modified by Gill is used to solve the non-dimensional boundary
layer equations for non-Newtonian flow field. Without fluid injection, for every angle of wedge β, a limiting value for velocity ratio λ
cr
(velocity of the wedge surface/velocity of the uniform flow) is found for each power-law index n. The value of λ
cr
increases with the increasing wedge angle β. The value of wedge angle also restricts the physical characteristics of the fluid to be used. The effects of the different
parameters on velocity profile and on skin friction are studied and the drag reduction is discussed. In case of C = 2.5 and velocity ratio λ = 0.2 for wedge angle β = 0.5 with the fluid with power law-index n = 0.5, 48.8% drag reduction is obtained. 相似文献
20.
The combined effect of a vertical AC electric field and the boundaries on the onset of Darcy–Brinkman convection in a dielectric
fluid saturated porous layer heated either from below or above is investigated using linear stability theory. The isothermal
bounding surfaces of the porous layer are considered to be either rigid or free. It is established that the principle of exchange
of stability is valid irrespective of the nature of velocity boundary conditions. The eigenvalue problem is solved exactly
for free–free (F/F) boundaries and numerically using the Galerkin technique for rigid–rigid (R/R) and lower-rigid and upper-free
(F/R) boundaries. It is observed that all the boundaries exhibit qualitatively similar results. The presence of electric field
is emphasized on the stability of the system and it is shown that increasing the AC electric Rayleigh number R
ea is to facilitate the transfer of heat more effectively and to hasten the onset of Darcy–Brinkman convection. Whereas, increase
in the ratio of viscosities Λ and the inverse Darcy number Da
−1 is to delay the onset of Darcy–Brinkman electroconvection. Besides, increasing R
ea and Da
−1 as well as decreasing Λ are to reduce the size of convection cells. 相似文献