双旋流模型燃烧室高温区演化分析

Focusing on the evolution problem of high temperature zones of swirled flame, using Aero Engine Combustor Simulation Code (AECSC), a two-phase turbulent combustion program based on the LES-TPDF method, the flow field of gas turbine model combustor (GTMC), which is a radial double-swirled model combustor, was simulated. When the temperature of the zones is higher than 1700K, they are defined as high temperature zones, and the time that high temperature zones rotate around the center once is defined as a period. The evolution of local high temperature zones in the flow field was studied within the range of axial Y/D=0-5. The results show that there exists a low-frequency large-scale vortex structure (precession vortex core(PVC)) near the shear layer of the flow field. PVC leads to the precession characteristic of the nearby fluid and promotes combustion and releasing heat. Within the range of Y/D=0-5 in the axial direction, the selected high temperature zones are in the same large-scale flow structure in space. Therefore, the changed frequencies of the high-temperature zones on different sections perpendicular to the axial direction are around 1000-2500Hz, which is similar to the changed frequency of the PVC. To sum up, PVC leads to the instability of combustion field and affects the formation and evolution of high temperature zones.