I.V. Golubkina, A.N. Osiptsov, V.I. Sakharov
Supersonic low-concentration dusty-gas flow past a plane cylinder in the presence of an oblique shock wave interacting with the bow shock
// Fluid Dynamics. 2011. V.46. N.1. P. 51-63.

I.V. Golubkina, A.N. Osiptsov
Shock Wave Interaction in a Dusty Gas and the Appearance of Fully Dispersed Waves
// Fluid Dynamics. 2010. V.45. N.1. P. 62-73.

S.A. Boronin and A.A. Osiptsov
Two-continua model of suspension flow in a hydraulic fracture
// Doklady Physics. 2010. V. 55. N 4. pp. 199-202.

Osiptsov A.N., Rybdylova O.D.
Focusing effect for aerosol particles behind a shock wave moving in a microchannel
// Doklady Physics. 2010. V. 55. No. 7. pp. 362-365.

S.A. Boronin
Stability of dispersed plane Couette flow with the finite volume fraction of particles
// (Submitted to Fluid Dynamics journal in 2010)

S.A. Boronin
Hydrodynamic stability of stratified suspension flow in a plane channel
// Doklady Physics. 2009. V. 54. No. 12. pp. 536-539.

Nevskii Yu. A., Osiptsov A.N.
Modeling of gravitational convection in suspensions
// Technical Physics Letters. 2009. V. 35. ?4.
Full text in russian

Lebedeva N.A., Osiptsov A.N.
Structure of inertial-admixture accumulation zones in a tornado-like flow
// Fluid Dynamics, 2009. V. 44, N. 1, pp.68-79.

Lebedeva N.A., Osiptsov A.N.
Modeling of local particle accumulation in disperse flows with kinematic singularities
// PAMM Proc. Appl. Math. Mech. 2008. ? 8. P. 10627-10628.

S.A. Boronin
Investigation of the stability of a plane-channel suspension flow with account for finite particle volume fraction
// Fluid Dynamics. 2008. V. 43. ? 6. pp. 873-884.

A.A. Koroteev, A.N. Osiptsov and E.S. Popushina
Nonisothermal Flow in a Conic Liquid Trap under Conditions of Atmosphere-Free Space
// High Temperature, 2008, Vol. 46, No. 6, pp. 827-834.

S.A. Boronin and A.N. Osiptsov
Stability of a disperse-mixture flow in a boundary layer
// Fluid Dynamics. 2008. V.43. 1. P.66-76.

N.A. Lebedeva and A.N. Osiptsov
Flows near stagnation points in non-orthogonally colliding disperse viscous flows
// Fluid Dynamics. 2007. V.42. 5. P.754-765.

I.V. Golubkina, A.N. Osiptsov
Aerodynamic Focusing of Inertial Particles in the Shock-Wave Intersection Region
// Fluid Dynamics. 2007. V.42. 4. P.603-611.

E.S. Asmolov
Numerical simulation of rarefied suspension sedimentation in a container
// Fluid Dynamics. 2007. V.42. 3. P.410-418.

Lebedeva N.A., Osiptsov A.N.
Admixture stratification in the stagnation region of two streams
// PAMM Proc. Appl. Math. Mech. 2006. ? 6. P. 569-570.

The motion of an inertial dispersed admixture near a plane cylinder immersed in a steady-state hypersonic dusty flow in the presence of an oblique shock wave interacting with the bow shock is considered. It is assumed that the free-stream particle mass concentration is small and the particles do not affect the carrier flow. The III and IV shock wave interaction regimes are considered. The gas flow parameters in the shock layer are calculated from the numerical solution of the full Navier-Stokes equations for the perfect gas. A TVD second-order finite-difference scheme constructed on the basis of a finite volume method is used. For calculating the dispersed-phase parameters, including the concentration, the full Lagrangian method is used. On a wide range of variation of the particle inertia parameters, the patterns of the particle trajectories, velocity, concentration, and temperature in the shock layer are studied. The possibility of aerodynamic focusing of the particles behind the shock wave intersection point and the formation of narrow beams with a high particle concentration is revealed. These beams impinge on the cylinder surface and result in a sharp increase in the local heat fluxes. The maximal possible increase in the heat fluxes caused by the particles colliding with the cylinder surface is estimated for the flows with and without the incident oblique shock wave.

A problem of regular (symmetric and asymmetric) interaction of plane shock waves in a steady-state dusty-gas flow is considered. The possibility of the formation of wave structures is revealed, in which either all or some of the incident or reflected waves degenerate into fully dispersed waves, i.e. zones in which the parameters of both phases vary continuously. Using the Rankine-Hugoniot relations for a one-velocity "effective-gas" model, the ranges of nondimensional governing parameters (theMach number, the angles between the incident waves and the free stream, the phase specific-heat ratio, and the particle mass concentration) are found, which correspond to different wave configurations. In the framework of a two-fluid dusty-gas model, the flow structure in the region of symmetric interaction of the shocks is calculated numerically for typical configurations containing fully dispersed waves. The flow in the region of a normal fully dispersed wave is also calculated. Good agreement between the calculated wave structure and the data known in the literature is obtained. A range of governing parameters in which the carrier-phase temperature has a local maximum inside the wave structure is found.

We consider the problem on shock-wave motion through a narrow channel in a viscous aerosol medium. The two-continuum model of dusty gas is accepted, the effect of particles on the carrier phase being neglected. The gas parameters are found from the numerical solution of the Navier-Stokes equations in the narrow-channel approximation. The dispersed-phase parameters are calculated with the help of the full Lagrangian method. In the interphase momentum exchange, we take into account the Saffman lift force in addition to the aerodynamic drag force. As a result of parametric calculations, we revealed the range of parameters in which the particles are focused behind the shock wave on the channel axis, the focusing being caused by the action of transverse forces on particles, which arises because of the shear nature of the flow on the particle scale. The found particlefocusing effect can be useful for developing technologies with focused beams of microparticles (cold deposition, needle-free powder-drag injection, the fractionation of aerosols, etc.).

Abstract will be published soon

Abstract will be published soon

The motion of a dispersed inertial admixture in a steady-state axisymmetric 3D viscous incompressible flow formed by a semi-infinite vortex filament interacting with an orthogonally located substrate surface is considered. The carrier-phase parameters are found from the numerical solution of the Navier-Stokes equations under the assumption of flow self-similarity of a known type. Different phase force interaction schemes corresponding to different ratios of the phase densities are considered. For calculating the dispersed-phase continuum parameters, a full Lagrangian approach is used, which makes it possible to calculate the dispersed-phase concentration in particle accumulation zones and regions of intersecting particle trajectories. On the basis of parametric calculations, it is found that in the case of heavy particles (whose density is greater than that of the carrier phase) a "cup-shaped" particle accumulation surface visualizing a high-vorticity region is formed. The dependence of this surface shape on the governing parameters is investigated. It is shown that for different phase density ratios the dispersed-phase concentration fields are qualitatively different.

A self-similar 2D steady-state flow of two immisible viscous fluids with inertial particles is considered. It is assumed that two viscous streams, one of which contains the particles, collide forming a flat interface with a stagnation point. The general case is discussed, when the fluids have different viscosities and densities and the streams are directed at arbitrary angles. The far field corresponds to inviscid vortex flow near an oblique stagnation point. The limiting case of viscous dusty flow near a rigid plane is studied in detail within one-way and two-way coupling approximations. Thin zones of particle accumulation are detected. Threshold parameters corresponding to the change of flow regime are found.

Within the framework of the two-fluid approach, a variant of a heterogeneous-medium model which takes into account a finite volume fraction of the inclusions and a small but finite phase velocity slip is proposed. The interphase momentum exchange is described by the Stokes force with the Brinkman correction for the finite particle volume fraction. The suspension viscosity depends on the particle volume fraction in accordance with the Einstein formula. Within the framework of the model constructed, a formulation of the problem of linear stability of plane-parallel two-phase flows is proposed. As an example, the stability of a channel suspension flow is considered. The system of equations for small disturbances with the boundary conditions is reduced to an eigenvalue problem for a fourth-order ordinary differential equation. Using the orthogonalization method, the dependence of the critical Reynolds number on the governing nondimensional parameters of the problem is studied numerically. It is shown that taking a finite volume fraction of the inclusions into account significantly affects the laminar-turbulent transition limit.

A nonisothermal film flow is considered, which is formed on the inside surface of a conic liquid trap, to the inlet of which a homogeneous flow of monodisperse droplet medium is delivered under conditions of atmosphere-free space. Asymptotic models of steady film flow are constructed and investigated for the conditions of inertial deposition of droplets under the assumption of small relative thickness of film and of the effect of secondary droplets formed upon deposition on the film surface. For a slow flow, the shape of the surface and the parameters of the film are found analytically. A parametric numerical investigation of distributions of velocity, temperature, and film thickness is performed for the general case. The parameters of flow in the inlet section of the offtake channel are found, and the conditions are determined which are required for maintaining a steadystate mode of operation of the drip pan.

The hydrodynamic stability of a dilute disperse mixture flow in a quasi-equilibrium region of a boundary layer with a significantly nonuniform particle concentration profile is investigated. The mixture is described by a two-fluid model with an incompressible viscous carrier phase. In addition to the Stokes drag, the Saffman lifting force is taken into account in the interphase momentum exchange. On the basis of a numerical solution of the boundary-value problem for a modified Orr-Sommerfeld equation, neutral stability curves are analyzed and the dependence of the critical Reynolds number on the governing parameters is studied. It is shown that taking into account the particle concentration nonuniformity in the main flow and the Saffman lifting force significantly changes the stability limits of the two-phase laminar boundary layer flow. The effect of these factors on the boundary layer stability is considered for the first time.

Within the framework of a two-fluid dusty-gas model, a family of steady self-similar flows near a stagnation point formed by two different non-orthogonally colliding viscous incompressible streams, one of which contains solid inertial particles, is studied. The limiting case of non-orthogonal impingement of a viscous disperse medium on a rigid wall is considered separately. The possibility of the formation of multiple particle accumulation zones on the envelopes of particle trajectories and on the contact (in the limiting case, rigid) surface is demonstrated. The local structure of the particle velocity and concentration fields is studied. The threshold values of the governing parameters corresponding to qualitative flow pattern reconstruction are found.

The flow structure in the region of intersection of two stationary plane shock waves in a dusty gas is investigated. The regular symmetric and asymmetric shock interaction and the symmetric Mach interaction are considered. For a small particle mass concentration, on the basis of numerical calculations using the full Lagrangian approach it is shown that behind the shock wave intersection point a long thin region is formed, in which the particle trajectories intersect and the particle concentration sharply increases. A parametric study of the particle concentration distributions in this region is performed and the range of governing parameters on which the particle focusing effect is maximal is found.

The evolution of the large-scale velocity perturbations in a homogeneous suspension sedimenting in a rectangular container with rigid horizontal walls and periodic conditions on the vertical boundaries is considered. Numerical simulation of the point-particle motion showed that the density and velocity fluctuations decrease with time. The perturbations are damped due to reshaping of the sedimentation front and the nonlinear interaction of the different modes.

A self-similar 2D steady-state flow of two immisible viscous fluids with inertial particles is considered. It is assumed that two viscous streams, one of which contains the particles, collide forming a flat interface with a stagnation point. The general case is discussed, when the fluids have different viscosities and densities and the streams are directed at arbitrary angles. The far field corresponds to inviscid vortex flow near an oblique stagnation point. The limiting case of viscous dusty flow near a rigid plane is studied in detail within one-way and two-way coupling approximations. Thin zones of particle accumulation are detected. Threshold parameters corresponding to the change of flow regime are found.