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.

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