Deposition of particles in the supersonic flow past a wedge

摘要

In our previous research, we find three particle motion patterns when submicron particles enter a supersonic laminar boundary layer over a flat plate. In these three patterns the deposition pattern is the most intriguing one because it is the lateral lift force directed to the wall that results in the particle deposition, hence the lateral deposition. In this paper, we investigate the particle motion in the supersonic flow past a wedge instead of a flat plate. The inertial deposition mechanism is introduced when the wedge replaces the flat plate. The inertial deposition is essential for the whole deposition process. Therefore, we build a two dimensional Eulerian Lagrangian numerical model to investigate this process. Several factors including particle initial position, wedge angle, initial Mach number and particle size are studied. It turns out that the higher particle has a more important lateral deposition mechanism, and as the wedge angle, initial Mach number or particle size increase, the importance of inertial deposition increases. Finally, as the three particle motion still exists in the wedge cases, we also propose a non-dimensional number to describe these patterns. (C) 2016 Elsevier B.V. All rights reserved.