Effect of air injection mode on the performance of a novel vortex-controlled flameholder for aircraft engine

To enhance flame stability and combustion performance under low pressure and high flow conditions in the afterburner, particularly with respect to the lean ignition and blowout limit, this study proposes a novel vortexcontrolled flameholder featuring two distinct air injection modes. Additionally, experimental and numerical studies were conducted to investigate the influence of air injection mode on the flow field and combustion characteristics of the vortex-controlled flameholder. The influence was directly investigated in terms of flow field, lean ignition and blowout, flame propagation, and outlet temperature rise. The results indicate that the flow fields of both cases (case-1 with a flow guide vane, and case-2 without a flow guide vane) are primarily composed of a main vortex, a secondary vortex, and a symmetrical vortex, which collectively contribute to flame stabilization. Following successful ignition, the main vortex of case-1 is protected by more walls, resulting in relatively favorable flame propagation and stability performance. In contrast, case-2 exhibits superior lean ignition and blowout performances compared to case-1. The outlet temperature rise in case-1 is significantly greater than that in case-2. The vortex-controlled flameholder, featuring two air injection modes, demonstrates improved flow field and combustion performance, which can be attributed to its distinct design. The findings of this study are expected to provide valuable insights for the optimization and design of flame stabilization systems in current and future aircraft engines.