Computation of Supersonic Branching Flow with Aerosol Particle Separation

Abstract

Supersonic branching flows are commonly found in industrial processes like the supersonic aerosol particle separation process and the supersonic inlet of combined aeroengines. In this research, we carry out a numerical study on the supersonic branching flow to reveal its features and its effects on aerosol particle separation. It is found that there are four flow regimes and a critical state in the supersonic branching flow in terms of the shock wave positions, which are determined by the backpressures of the two outlets. The gas flow rate ratio and the particle separation ratio are closely related to the flow regimes. There is a steady working zone where the gas flow rate ratio and the particle separation ratio maintain as constant as the two backpressures vary. In swirling flows, there is a drift of the critical state. In the range of particle sizes studied here, the particle motion is not sensitive to the variations of the particle size in the absence of swirl, but it is not the case for swirling flows. Finally, some features of the steady working zone are discussed. This work is a preliminary research into supersonic branching flow and provides a foundation for the design of relevant devices.