Characteristics of Shock Train Flow in Divergent Channels

Abstract

In a Supersonic intake, the supersonic flow decelerates to subsonic speed inside the isolator by a series of compression waves. This wave phenomenon is referred to as shock train region. The length of the shock train is one of the main consent in designing the isolator. The isolator can be a constant or nearly constant area duct. The flow characteristic of shock train is depending on several parameters which makes the difficulties in designing the isolator for each particular engine. Also, the shock train strongly affects the performance of the various flow devices. The length of the shock train region can be able to predict using the upstream flow parameters; whereas, the diffusion region depends on both the upstream flow parameters and also influenced more by geometrical parameters. In the present work, the characteristic of shock train is analyzed using computational fluid dynamics method. The effects of upstream flow Mach number and different back pressure with the different divergent angle are considered in the present study. Studies have shown the total pressure loss increase with increase in divergent angle and also the blockage ratio decrease with the divergent angle.