Ignition prediction method for swirling spray combustor

A rapid engineering ignition prediction method for an aero-engine swirling two-phase spray was developed using the commercial software Fluent combined with user-defined function, which considers the influence of spray dispersity on the ignition process. Experimental data related to the ignition study were obtained via optical measurements to verify the reliability of the proposed ignition prediction method. Then, the ignition performance at various ignition positions within a combustor was predicted under ground conditions. Results indicate the following: (1) The numerical calculation method for nonreacting flow is verified using particle image velocimetry and planar Mie scattering test data, which can be used to accurately capture the flow field and fuel mist field distribution characteristics of the swirling two-phase spray combustor. (2) A low Karlovitz number and an appropriate flammability factor are exhibited in the vicinity of the igniter plug and throughout most regions in the combustor. Such distribution characteristics provide favorable conditions for the formation and growth of the initial flame kernel. (3) Within the investigated range of ignition positions, the ignition performance improves with the ignition position gradually moving away from the dome of the combustor. Consequently, to improve the ignition performance within the combustor under ground conditions, it is recommended to move the existing igniter plug backward along the central axis of the combustor. The above-mentioned research results provide a rapid numerical research method for the ignition optimization design of aero-engine combustors in engineering.