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1.
A kinetic model for the probability density function (PDF) of the particle velocity in a turbulent flow with account for particle
collisions is presented. The model is tested by comparison with the results of a numerical experiment for a nonstationary
homogeneous shear layer.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 4, pp. 105–112, July–August, 1998.
The study received financial support from the International Science Foundation INTAS (project No. 94-4348) and the Russian
Foundation for Basic Research (project No. 97-01-00398). 相似文献
2.
Particle deposition from a turbulent flow 总被引:4,自引:0,他引:4
The diffusion equations and boundary condition for particle deposition from a turbulent flow are obtained on the basis of
the kinetic equation for the probability density of the particle distribution. This approach makes it possible to calculate
the deposition fairly simply without introducing additional empirical information relating to the particles (empirical constants
are needed only for calculating the characteristics of the turbulent carrier flow).
Moscow. Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 96–104, September–October, 1988. 相似文献
3.
K. N. Volkov 《Journal of Applied Mechanics and Technical Physics》2008,49(3):425-436
The motion and heat and mass transfer of particles of a disperse admixture in nonisothermal jets of a gas and a low-temperature
plasma are simulated with allowance for the migration mechanism of particle motion actuated by the turbophoresis force and
the influence of turbulent fluctuations of the jet flow velocity on heat and mass transfer of the particle. The temperature
distribution inside the particle at each time step is found by solving the equation of unsteady heat conduction. The laws
of scattering of the admixture and the laws of melting and evaporation of an individual particle are studied, depending on
the injection velocity and on the method of particle insertion into the jet flow. The calculated results are compared with
data obtained with ignored influence of turbulent fluctuations on the motion and heat and mass transfer of the disperse phase.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 3, pp. 95–108, May–June, 2008. 相似文献
4.
5.
A. Yu. Boris 《Fluid Dynamics》1986,21(6):889-894
The motion is considered of a Stokes-like spherical particle in a turbulent nonisothermic gas flow whose viscosity depends
on the temperature. The field of the turbulent velocity is assumed to be homogeneous, isotropic, and steady. It is shown that
if there is a mean temperature gradient in the gas, and, consequently, a heat flow due to turbulent pulsations, then there
may be turbulent migration of particles in a direction collinear with the gradient of the mean temperature. The migration
is due to statistical correlation of turbulent pulsations of velocity and temperature, and is not connected with the phenomenon
of ordinary thermophoresis. Upon the introduction of a number of simplifying assumptions, the rate of migration is calculated
in dependence on the characteristics of the particle and the flow.
Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 53–58, November–December, 1986.
The author is grateful to V. S. Galkin, V. A. Zharov, M. N. Kogan, and V. A. Sabel'nikov for discussions of the study. 相似文献
6.
An explicit formula is derived for the rate of deposition of large particles (droplets) on a tube wall in two-phase turbulent
flow.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 68–75, March–April, 1998.
The work was financially supported by the International scientific foundation INTAS (grant No. 94-4348) and by the Russian
Foundation for Fundamental Research (project No. 97-01-00398). 相似文献
7.
The turbulent fluid and particle interaction in the turbulent boundary layer for cross flow over a cylinder has been experimentally
studied. A phase-Doppler anemometer was used to measure the mean and fluctuating velocities of both phases. Two size ranges
of particles (30μm–60μm and 80μm–150μm) at certain concentrations were used for considering the effects of particle sizes
on the mean velocity profiles and on the turbulent intensity levels. The measurements clearly demonstrated that the larger
particles damped fluid turbulence. For the smaller particles, this damping effect was less noticeable. The measurements further
showed a delay in the separation point for two phase turbulent cross flow over a cylinder.
The project supported by the National Natural Science Foundation of China 相似文献
8.
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
9.
In this work we examine first the flow field of a confined jet produced by a turbulent flow in a long cylindrical pipe issuing
in an abrupt angle diffuser. Second, we examine the dispersion of inertial micro-particles entrained by the turbulent flow.
Specifically, we examine how the particle dispersion field evolves in the multiscale flow generated by the interactions between
the large-scale structures, which are geometry dependent, with the smaller turbulent scales issued by the pipe which are advected
downstream. We use Large-Eddy-Simulation (LES) for the flow field and Lagrangian tracking for particle dispersion. The complex
shape of the domain is modelled using the immersed-boundaries method. Fully developed turbulence inlet conditions are derived
from an independent LES of a spatially periodic cylindrical pipe flow. The flow field is analyzed in terms of local velocity
signals to determine spatial coherence and decay rate of the coherent K–H vortices and to make quantitative comparisons with
experimental data on free jets. Particle dispersion is analyzed in terms of statistical quantities and also with reference
to the dynamics of the coherent structures. Results show that the particle dynamics is initially dominated by the Kelvin–Helmholtz
(K–H) rolls which form at the expansion and only eventually by the advected smaller turbulence scales. 相似文献
10.
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
11.
The process of spanwise propagation of turbulence in a laminar boundary layer on a plate is numerically investigated. Three
well-known turbulence models are considered. It is shown that the calculated values of the "turbulent wedge" angle are several
times less than that observed experimentally. The reason for the deviation of the calculated and experimental data is analyzed.
Moscow, Seattle. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 77–84, May–June,
1998.
The work was financially supported by the Russian Foundation for Basic Research (project No. 95-01-00251a) and the Moscow
Boeing Science-Technology Center. 相似文献
12.
The influence of high-frequency acoustic excitation of a submerged round turbulent jet flowing out of a nozzle with both laminar
and turbulent boundary layers at the nozzle outlet on the suppression of turbulent velocity fluctuations in the initial and
transition regions of the jet is experimentally investigated. It is established that in the case of the turbulent boundary
layer a higher excitation level is needed to realize the suppression effect than in the case of the laminar boundary layer.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 28–34, January–February,
1999.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 96-02-19577). 相似文献
13.
S. I. Martynov 《Fluid Dynamics》2000,35(1):68-74
The hydrodynamic interaction of two rigid spherical particles in a viscous incompressible fluid with the velocity at infinity
represented by a second-degree polynomial in the coordinates is considered. An analytical solution of the problem is suggested.
The forces and torques exerted on the particles and also the linear and angular particle velocities are calculated. The results
are compared with previous theoretical and experimental data.
Saransk. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 84–91, January–February,
2000.
The work received financial support from the Russian Foundation for Basic Research (project No. 98-01-03295). 相似文献
14.
The shell model of developed convective turbulence of an incompressible fluid is considered. Regimes developing at high Rayleigh
numbers are investigated numerically for three- and two-dimensional motion. It is shown that in the three-dimensional turbulent
convection model the inertial Obukhov-Bolgiano interval is developed on large scales, but this interval is unstable and gives
way to the Kolmogorov regime in which the temperature behaves as a passive admixture. In the two-dimensional turbulent convection
model a finite scale interval on which the buoyancy forces determine the nature of the fluctuations but the spectral laws
established differ from those that follow from dimensional considerations for the Obukhov-Bolgiano interval is detected.
Perm’. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 6, pp. 37–46, November–December,
1998.
The work was carried out with financial support from the Russian Foundation for Basic Research (project No. 94-01-00951a). 相似文献
15.
Bert Vreman Bernard J. Geurts N. G. Deen J. A. M. Kuipers J. G. M. Kuerten 《Flow, Turbulence and Combustion》2009,82(1):47-71
Large-eddy simulations (LES) of a vertical turbulent channel flow laden with a very large number of solid particles are performed.
The motivation for this research is to get insight into fundamental aspects of co-current turbulent gas-particle flows, as
encountered in riser reactors. The particle volume fraction equals about 1.3%, which is relatively high in the context of
modern LES of two-phase flows. The channel flow simulations are based on large-eddy approximations of the compressible Navier–Stokes
equations in a porous medium. The Euler–Lagrangian method is adopted, which means that for each individual particle an equation
of motion is solved. The method incorporates four-way coupling, i.e., both the particle-fluid and particle–particle interactions
are taken into account. The results are compared to single-phase channel flow in order to investigate the effect of the particles
on turbulent statistics. The present results show that due to particle–fluid interactions the mean fluid profile is flattened
and the boundary layer is thinner. Compared to single-phase turbulent flow, the streamwise turbulence intensity of the gas
phase is increased, while the normal and spanwise turbulence intensities are reduced. This finding is generally consistent
with existing experimental data. The four-way coupled simulations are also compared with two-way coupled simulations, in which
the inelastic collisions between particles are neglected. The latter comparison clearly demonstrates that the collisions have
a large influence on the main statistics of both phases. In addition, the four-way coupled simulations contain stronger coherent
particle structures. It is thus essential to include the particle–particle interactions in numerical simulations of two-phase
flow with volume fractions around one percent. 相似文献
16.
The results of the numerical simulation of supersonic three-dimensional flow past sharp-nosed cones with circular and elliptic
cross-sections in the turbulent shock-layer flow regime are presented. The calculations are performed in the local conical
approximation using the system of Reynolds equations and the differential one-equation turbulence model. The numerical solutions
are obtained by means of an implicit constant-direction finite-difference scheme. The emphasis is placed on the investigation
of the transverse flow separation and the flow features associated with the turbulent flow regime.
St.Petersburg. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 99–105, January–February,
2000.
The study was carried out with the support of the Russian Foundation for Basic Research (project No. 99-01-00735). 相似文献
17.
P. G. Zaets A. F. Kurbatskii A. T. Onufriev S. V. Poroseva N. A. Safarov R. A. Safarov S. N. Yakovenko 《Journal of Applied Mechanics and Technical Physics》1998,39(2):249-260
The vorticity formed in the cross section of a turbulent flow in a straight circular pipe rotating about its longitudinal
axis decreases the values of the turbulent stresses, turbulence energy, and dissipation rate along the pipe. The results of
laboratory experiments and calculations by the second-order closure model of turbulent transfer are presented. On the whole,
the model using a system of transport equations yields better agreement with experimental data than the models with algebraic
relations for second-order moments.
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 39, No. 2, pp. 103–116, March–April, 1998. 相似文献
18.
The results of calculating a supersonic turbulent boundary layer on a flat plate in the presence of thermal energy supply
to the boundary layer are presented. Two methods of energy supply are considered: heating a local interval of the surface,
which is otherwise thermally insulated and using a local volume heat source. It is shown that for the same amount of heat
supplied to the gas volume heating leads, under certain conditions, to greater friction reduction than the surface heating.
Localization of the energy supply zone leads to the intensification of the viscous drag reduction effect and to a greater
decrease in the local friction coefficient, which extends a considerable distance downstream.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 48–56, January–February,
1997.
The work was carried out with financial support from the Russian Foundation for Fundamental Research (project No. 93-013-17600). 相似文献
19.
A physical mechanism of onset of large-scale organized structures in turbulent flows along a plane wall which are the cause
of intensification of turbulent fluctuations is formulated. The structures take the form of high-speed and low-speed streaks
caused by streamwise vortices, i.e., motions in the plane of the transverse cross-section. The streamwise vortices are excited
as a result of instability under the action of the anisotropy of the normal components of the Reynolds stress tensor. A model
for describing these vortices that gives characteristics in qualitative and quantitative agreement with the experimental data
is proposed. In particular, the most probable and mean distances between neighboring vortices are correctly reproduced. The
theory makes it possible to explain certain methods of turbulent flow control for the purpose of drag reduction.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 24–30, January–February,
1997.
The work was carried out with financial support from the Russian Foundation for Fundamental Research (project No. 96-01-00602). 相似文献
20.
The levels and spectra of pressure oscillation on a plane upstream of a vertical cylinder and a step in an M=3 supersonic
flow are measured in the presence of a turbulent boundary layer.
Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 69–74, January–February,
1998. 相似文献