Focusing of inertial particles after the shock-wave intersection point

2007 ◽  
Vol 5 ◽  
pp. 145-150
Author(s):  
I.V. Golubkina

The effect of the aerodynamic focusing of inertial particles is investigated in both symmetric and non-symmetric cases of interaction of two plane shock waves in the stationary dusty-gas flow. The particle mass concentration is assumed to be small. Particle trajectories and concentration are calculated numerically with the full Lagrangian approach. A parametric study of the flow is performed in order to find the values of the governing parameters corresponding to the maximum focusing effect.

1981 ◽  
Vol 108 ◽  
pp. 147-157 ◽  
Author(s):  
R. M. Barron ◽  
J. T. Wiley

Hypersonic small-disturbance theory is extended to consider the problem of dusty-gas flow past thin two-dimensional bodies. The mass fraction of suspended particles is assumed to be sufficiently large that the two-way interaction between particle phase and gas phase must be considered. The system of eight governing equations is further reduced by considering the Newtonian approximation γ → 1 andM∞→ ∞. The Newtonian theory up to second order is studied and the equations are solved for the case of a thin wedge at zero angle of attack. Expressions for the streamlines, dust-particle paths, shock-wave location and all flow variables are obtained. It is seen that the presence of the dust increases the pressure along the wedge surface and tends to bend the shock wave towards the body surface. Other effects of the interaction of the two phases are also discussed.


Supersonic flows of a dusty gas past a wedge are studied theoretically. An oblique shock wave emanates from the apex of the wedge at the same angle as in the case of a pure gas, but bends back because of the presence of the particles. It is shown from an equilibrium-gas analysis that the extent of decrease in the shock-wave angle is larger for smaller velocity of the uniform stream. When the flow-deflection angle is small enough, the oblique shock wave developing fully at large distances from the apex has a fully dispersed transition structure. On the other hand, it is partly dispersed when the flow-deflection angle is large. Details of the development of the oblique shock wave as the distance from the apex increases are clarified by solving the equations of motion numerically. The particles colliding with the wedge are assumed to stick to or reflect elastically from its surface. It is shown that the reflected particles affect the flow significantly in the neighbourhood of the wedge.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Pooja Gupta ◽  
Rahul Kumar Chaturvedi ◽  
L. P. Singh

AbstractThe present study uses the theory of weakly nonlinear geometrical acoustics to derive the high-frequency small amplitude asymptotic solution of the one-dimensional quasilinear hyperbolic system of partial differential equations characterizing compressible, unsteady flow with generalized geometry in ideal gas flow with dust particles. The method of multiple time scales is applied to derive the transport equations for the amplitude of resonantly interacting high-frequency waves in a dusty gas. These transport equations are used for the qualitative analysis of nonlinear wave interaction process and self-interaction of nonlinear waves which exist in the system under study. Further, the evolutionary behavior of weak shock waves propagating in ideal gas flow with dust particles is examined here. The progressive wave nature of nonresonant waves terminating into the shock wave and its location is also studied. Further, we analyze the effect of the small solid particles on the propagation of shock wave.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
G. Nath

Abstract The approximate analytical solutions are obtained for adiabatic and isothermal flows behind a cylindrical shock wave in a dusty gas. A mixture of perfect gas and micro size small inert solid particles is taken as the dusty gas. The inert solid particles are distributed continuously in the mixture. It is considered that the equilibrium flow conditions are maintained. The flow variables are expanded in power series to obtain the solution of the problem. The analytical solutions are obtained for the first order approximation in both the adiabatic and isothermal cases. Also, the system of ordinary differential equations for second order approximations to the solution is obtained. The influence of an increase in the ratio of the density of the inert solid particles to the initial density of the perfect gas, the rotational parameter and the mass concentration of inert solid particles in the mixture are discussed on the flow variables for first approximation. Our first approximation to the solution corresponds to the Taylor’s solution for the creation of a blast wave by a strong explosion. A comparison is also made between the solutions for isothermal and adiabatic flows. It is investigated that the density and pressure near the line of symmetry in the case of isothermal flow become zero and hence a vacuum is formed at the axis of symmetry when the flow is isothermal. Also, it is found that an increase in the value of rotational parameter or the mass concentration of solid particles in the mixture has a decaying effect on shock wave. The present work may be used to verify the correctness of the solution obtained by self-similarity and numerical methods.


Author(s):  
Alexander Osiptsov ◽  
Irina Golubkina ◽  
Oyuna Rybdylova

The effect of aerodynamic focusing of microparticles in gas-particle flows is employed mainly for creating collimated particle beams. These beams are used in various technical applications, such as coating, “direct-write”, surface processing technologies, needle-free injections, etc. In this study, we propose and investigate two new flow schemes in which the effect of aerodynamic focusing of small low-inertia particles may be realized in high-speed gas flows with shock waves. The first one is a steady-state dusty-gas flow behind the point of interaction of two crossing shock waves. The convergence of the carrier-phase streamlines and the presence of particle inertia result in the formation of a high-concentration particle beam behind the shock interaction point. In the second flow scheme considered, the particle focusing effect is attributable to the action of the Saffman lateral force, exerting on the particles in boundary layers behind a shock wave travelling in a narrow channel with a constant cross-section. In both cases, the ranges of governing parameters are found for which the focusing is “optimal”, i.e. a very thin collimated beam of microparticles is formed.


2007 ◽  
Vol 42 (4) ◽  
pp. 603-611 ◽  
Author(s):  
I. V. Golubkina ◽  
A. N. Osiptsov

2018 ◽  
Vol 49 (2) ◽  
pp. 105-118
Author(s):  
Volf Ya. Borovoy ◽  
Vladimir Evguenyevich Mosharov ◽  
Vladimir Nikolaevich Radchenko ◽  
Arkadii Sergeyevich Skuratov

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