共查询到20条相似文献,搜索用时 15 毫秒
1.
I. V. Derevich 《Fluid Dynamics》1998,33(4):497-511
Using a two-point probability density function for the particle distribution over velocities and coordinates, a closed model
of the particle effect on the turbulent flow characteristics is formulated. The processes of turbulent dissipation and turbulent
energy transfer across the spectrum are studied. Different models of two-phase turbulence are compared.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 40–56, July–August, 1998.
The work received financial support from INTAS (grant No. 94-4348) and the Russian Foundation for Basic Research (project
No. 98-01-00-353). 相似文献
2.
Steady turbulent viscous incompressible fluid flow in a plane channel is calculated for the case of uniform blowing and suction
through opposite walls. There are no experimental data for flows of this type. The flows were calculated by two methods: a
direct numerical simulation method and using a three-parameter turbulence model. Direct numerical simulation was carried out
using the same (apart from the boundary conditions) algorithm for numerical solution of the Navier-Stokes equations as that
used earlier for calculating flows in pipes and channels with impermeable walls. In the second group of calculations the version
of the model published in 1978 was used. The results obtained by the two methods are in good agreement. The difference is
within the spread of the experimental data used for determining the parameters of the model. The agreement obtained makes
it possible to assert that the turbulence direct numerical simulation algorithm developed can be used for the analysis of
flows with quite different boundary conditions, including cases where there are no corresponding experimental data.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 18–26, November–December,
1998.
The work was financially supported by the Russian Foundation for Basic Research (project Nos. 96-01-00602 and 96-01-00259). 相似文献
3.
The integral relations, the algebraic model, and the family of differential turbulence models widely used in theoretical and
practical boundary layers studies are considered. The differential turbulence models are analyzed for fully developed incompressible-fluid
flow in three regions: the viscous sublayer, the logarithmic layer, and the flow core. Numerical results are compared with
analytical and experimental dependences. The numerical results for the boundary layer in a liquid rocket engine (LRE) nozzle,
where compressibility, the temperature factor, and flow acceleration are significant, are presented. Recommendations on the
applicability of the turbulence models considered are given.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 44–58, January–February,
1998.
The work received financial support from the Russian Foundation for Fundamental Research (project No.96-01-00260). 相似文献
4.
For verifying the method of calculating the boundary layer in liquid rocket engine (LRE) nozzles developed by the authors
on the basis of a differential three-parameter turbulence model, the boundary layer on a plate in a zero-gradient flow is
calculated. Over a wide range of variation of the free-stream Mach number, the temperature factor, and the Reynolds number,
based on the momentum thickness of the boundary layer, the calculation agrees satisfactorily with the known experimental data,
with respect to both integral and local flow and heat transfer characteristics.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 64–78, November–December,
1998.
The work received financial support from the Russian Foundation for Basic Research (project No.96-012-00260). 相似文献
5.
The flow initiated by a hot gas cloud (thermal) in a stratified atmosphere is calculated on the basis of theκ-ε turbulence model and the transport model for the Reynolds stresses and turbulent fluxes and the results obtained are compared
The nonlocal nature of the turbulent transport in a vortex ring and its effect on certain flow characteristics are explained
In particular, the calculations carried out using the Reynolds stress model show much slower cooling of the temperature-vortex
torus than those based calculated on theκ-ε-model Modification of theκ-ε-model to take the effect of curvature of the streamlines approximately into account makes it only partially possible to reproduce
the results obtained on the basis of the Reynolds stress model
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 12–20, January–February,
1999.
The research was carried out with support from the Russian Foundation for Basic Research (project No. 95-01-00544a). 相似文献
6.
M. V. Ustinov 《Fluid Dynamics》1998,33(6):856-863
The linear stability of a boundary layer flow with a spanwise-periodic nonuniformity in the velocity profile is investigated.
This flow can be considered as a model of a streaky structure occurring in the boundary layer at a high freestream turbulence
level. It is shown that for a small nonuniformity amplitude symmetric modes similar to Tollmien-Schlichting waves are the
most unstable. At higher nonuniformity amplitudes, antisymmetric modes, qualitatively different from Tollmien-Schlichting
waves and having a larger phase velocity, are the most amplified.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 54–63, November–December,
1998.
The study was carried out with the support of the International Scientific and Technical Center (project No. 199-95) and the
Russian Foundation for Basic Research (project No. 95-01-01201a). 相似文献
7.
The results of a systematic experimental study of the flow turbulence level effect on the heat transfer and Reynolds analogy
coefficients over a wide range of the relevant parameters (the turbulence intensity and scale and the Reynolds number) are
presented. The notion of the equivalent flow turbulence, which unifies the above-mentioned parameters, is introduced. It is
established that the skin friction and heat transfer coefficients increase with the equivalent turbulence, while the Reynolds
analogy coefficient remains unchanged.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 61–71, January–February,
2000. 相似文献
8.
V. V. Aristov 《Fluid Dynamics》1998,33(2):280-283
Free supersonic underexpanded jets are studied using a direct method conservative splitting scheme for solving the Boltzmann
equation. Numerical solutions for a jet flowing into a vacuum and into a fluid-filled space are presented for the following
ranges of the parameters: Knudsen number 10−6<Kn<∞ and pressure ratio 10<n<∞. The solutions are compared with experimental data. Instabilities associated with free turbulence effects in the mixing
layer are detected for low Kn numbers.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 153–157, March–April, 1998.
The work was carried out with support from the Russian Foundation for Fundamental Research (project No. 96-01-00829). 相似文献
9.
A turbulent wake model, based on the Reynolds, energy and turbulence dissipation equations together with the closing relations
for the turbulent transport coefficients, is proposed. A comparative investigation of swirled momentumless wakes with zero
and nonzero angular momentum is carried out.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 13–22, January–February,
1994. 相似文献
10.
N. V. Nikitin 《Fluid Dynamics》2000,35(2):185-190
The attenuation of turbulent pulsations in near-wall flows by means of spanwise periodic surface oscillation is examined.
A direct numerical simulation of the flow in a circular pipe with imposed rotational oscillations has shown that for Re=4000
and the optimal oscillation frequency, the degree of turbulence attenuation increases with increase in the oscillation amplitude
until the flow relaminarizes. The estimated optimal frequency ω+=0.06. The results of applying the theory of the development of near-wall coherent structures agree qualitatively with those
of numerical simulation. It is concluded that the intensity of the pulsations is reduced because the spanwise movements weaken
the longitudinal vortices which cause turbulent bursts in near-wall flows.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 37–44, March–April, 2000.
The research was carried out with financial support from the Russian Foundation for Basic Research (project No. 99-01-01095). 相似文献
11.
A. P. Kuryachii 《Fluid Dynamics》1998,33(6):876-881
A solution of the coupled nonstationary boundary-value problem of turbulent flow around a flat heat-conducting plate of finite
thickness having local regions with volume heat sources is given. For modeling the heat transfer in the boundary layer, thek-ε turbulence model is used. It is shown that the thermal conductivity of the plate material significantly affects the surface
distributions of both temperature and local friction.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 79–86, November–December,
1998.
The work received financial support from the International Scientific and Engineering Center (project No.199). 相似文献
12.
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
13.
V. L. Zelenko 《Fluid Dynamics》1994,29(1):50-54
The monotonic instability of a horizontal layer of a viscous liquid with soluble-gas bubbles is demonstrated. The critical
values of the modified Archimedes number are calculated and the corresponding critical motions of the liquid are considered.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.1, pp. 65–70, January–February,
1994. 相似文献
14.
A model of the heterogeneous catalysis of a dissociated carbon dioxide — nitrogen mixture on high-temperature heat-shield
coatings is developed; the model takes into account nonequilibrium adsorption-desorption reactions of nitrogen and oxygen
atoms and carbon dioxide molecules and their recombination in the Eley-Rideal reactions. On the basis of a comparison of the
calculated heat fluxes in dissociated carbon dioxide with those measured on the VGU-4 plasma generator of the Institute for
Problems in Mechanics of the RAS, the parameters of the catalysis model in question are chosen for three modern oxidant-resistant
coating materials. The performances of these coatings are compared for the conditions of Mars Miniprobe entry into the Martian
atmosphere. Their usability for the entry path considered is shown.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 106–116, January–February,
2000.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 99-01-00259) and the
“Integratisya“ Federal Program (project No. 2.1–414). 相似文献
15.
T. V. Bazhenova S. B. Bazarov T. A. Bormotova V. V. Golub A. M. Shulmeister 《Fluid Dynamics》1998,33(2):190-195
The nonstationary interaction between a supersonic pulse jet and a flat plate perpendicular to the jet axis is studied experimentally
and numerically. The time dependences of the pressure and heat flux at various points on the obstacle and the spatial distribution
of the density are obtained experimentally. The nonstationary flow is calculated numerically by the Godunov method. The experiments
and calculations reveal the effect of the reflected starting shock wave and the front part of the swirled gas outflow on the
distribution of the dynamic and thermal loads acting on the plate, in both time and space.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 45–51, March–April, 1998.
This research was carried out with partial financial support from the Russian Foundation for Fundamental Research (project
No. 96-02-16170). 相似文献
16.
The stability of an axisymmetric flow of viscous gas in a circular pipe, which models the Burgers vortex in the pipe axis
neighborhood, is studied within the linear theory framework. Neutral curves for the most unstable disturbances are calculated.
The influence of the characteristic Mach number on the flow stability is investigated. It is shown that for a given model
velocity distribution the Mach number affects only the temperature and pressure profiles of the main undisturbed flow. In
this case, for the disturbance types considered, as the Mach number increases, the critical Reynolds number corresponding
to loss of stability decreases.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 35–41, January–February,
1999.
The work received financial support from the Russian Foundation for Basic Research (project No. 96-01-00586). 相似文献
17.
A. P. Kuryachii 《Fluid Dynamics》1998,33(1):48-55
The results of calculating a supersonic turbulent boundary layer on a heated surface on the basis of the algebraic two-parameter
(k-ε) and four-parameter (k-ε-θ
2-ε
6) models of turbulence are compared with experimental data. Emphasis is placed on the ability of the models to predict the
behavior of the friction and heat-transfer coefficients on a heated surface. The optimal model of turbulence is chosen. The
possibility of improving the efficiency of viscous drag reduction by localizing the regions of heat addition to the boundary
layer is demonstrated on the basis of numerical calculations.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 59–68, January–February,
1998.
This research was carried out with financial support from the International Scientific and Technological Center (project No.
199). 相似文献
18.
The results of measurements of the drag of axisymmetric bodies with smooth and ribbed central cylindrical sections and affinely
similar trailing edges of various lengths are given. The experimental data were obtained for zero angle of attack and the
numbers M=0.25–0.85 and Re=107–2.4·107 (calculated on the basis of the length of the body without the trailing section). The trailing-edge flow separation was visualized
by the oil film method. It is shown that ribbing can lead to a decrease in drag due not only to a reduction in turbulent friction
but also to reduction of the separation zone on the smooth trailing section of the body.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 163–168, January–February,
1998.
The work was carried out with the support of the International Science-Technology Center (project No. 199-95). 相似文献
19.
The interaction of a uniform hypersonic gas flow with a supersonic two-phase gas-particle source is considered. In the symmetry-axis
neighborhood between the bow and termination shock waves, an approximate analytical solution for the carrier-phase parameters
is found. On the basis of parametric numerical calculations, the behavior of the particle trajectories and the concentration
distribution in the shock layers are studied for both continuum and free-molecule flow regimes around the particles. The appearance
of regions with multiple intersections of the particle trajectories and the formation of "layer structures" in the particle
concentration distributions (particle accumulation regions near the envelopes of the particle trajectories) are indicated.
The dependence of the number of the high concentration layers on the governing parameters is studied.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 134–147, May–June, 1998.
The work received financial support from the Russian Foundation for Basic Research (project No. 96-01-00313) and the National
Foundation for Natural Sciences of China (joint RFBR-NFNS grant No.96-01-00017c). 相似文献
20.
The instability of a tangential discontinuity in a compressible dispersive medium with respect to small two-dimensional perturbations
is demonstrated.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 16–23, January–February,
1997.
The work was carried out with support from the Russian Foundation for Fundamental Research (project No. 96-01-01340). 相似文献