Study on the anti-flame holding mechanism of internal flow in an arrayed-vanes premixer

The arrayed-vanes premixer is an innovative conceptual design for gas turbine combustors. The principle of this design is to inhibit flame holding. The anti-flame holding mechanism was analyzed theoretically and experimentally based on a two dimensional fully developed model flow. The flow of the fully developed section in the arrayed-vanes premixer was proved to be stable for the length of the recirculation zone keeping almost constantly throughout Re=500~50000. An ignition analysis model was established, which revealed the sub-critical stability nature of this type of reacting flow and clarifies the operating condition to achieve anti-flame holding performance. The experimental study was carried out, which qualitatively verified the theoretical analysis and provided the measurements of the critical anti-flame holding velocity at various preheated temperatures (300~700K) and equivalence ratios (0.5~1.0). This paper provides a theoretical basis and fundamental data for the further research and development of the arrayed-vanes premixer in gas turbine combustors.