Inertial Effects on Linear and Locally Linear Flows

Abstract

The dynamics of a suspension of particles in a gas may be characterized by the coexistence of a nearly equilibrated incompressible component (the gas) with a highly compressible component, which is often very far from equilibrium (the particle phase). The governing equations for such a system are complicated due to the coupling between the two phases, and have been successfully solved in only a limited number of cases. In the first part of this paper the wide range of so-called “linear flows” (where the host gas velocity field varies linearly with position) for which the particle velocity field may be obtained analytically is introduced. Because the family of linear flows includes stagnation point flows, Couette flows, and solid body rotations, relatively wide conclusions may be reached on the particle behavior, with important implications for the aerodynamic separation of aerosols or heavy molecules. In particular, it is seen that sufficiently far downstream from particle injection points the particle ve...