Partially Premixed Ignition for a Bluff-Body Flameholder under Various Igniter and Inlet Conditions

Abstract

This study applies experimental methods to investigate the partially premixed ignition characteristics of a bluff-body flameholder with a pilot stage. The ignition fuel–air ratio (FAR) under different igniter and inlet conditions is obtained, while the ignition process is recorded with a high-speed photography device. Numerical simulations are carried out to investigate the relationship between the flow field, fuel distribution, and ignition process. The results show that a higher total capacitance energy storage of the igniter, inlet Mach number, or total pressure inside the combustion chamber will help increase the ignition performance, accelerate the development of the flame, and shorten the ignition delay. The flame propagation routine of the flameholder is controlled by several pairs of symmetrical recirculation zones behind the flameholder structure and the specific uneven fuel distribution caused by the flow field. This study provides a detailed understanding of the ignition process for the bluff-body flameholder.