关键词: 燃烧室;中心分级;多点直喷;流动特性;周期性边界;发散冷却

Abstract: The non-reaction flow characteristic of the concentric staged dual swirl multi-point direct injection combustor was investigated by numerical simulation and experiments. A quantitative description method of the main characteristic parameters of the recirculation zone was established. The development process of pilot/main module swirl flow in the combustor was analyzed. The mutual interference between the domes as well as the interaction between the effusion cooling air and the swirling air were obtained. According to the results， a stable central recirculation zone （CTRZ） is formed in the concentric staged dual swirl rectangular combustor （model A）， and the expansion angle of CTRZ is 30°， which is beneficial to the flame stabilization under the low conditions. In the combustor with periodic boundary condition （model B）， the vortex center in the corner recirculation zone （CORZ） moves downstream because of the mutual interference between domes. The size of CORZ significantly increases while the vortex center distance is decreased， which inhibits the development of the CTRZ. Therefore， two smaller CTRZs are formed and the expansion angle of the first CTRZ is reduced to 20°. In the combustor with effusion cooling holes （model C）， the effusion cooling air suppress the development of the CORZ， which disappears at the central section. A larger CTRZ is formed and the expansion angle of the CTRZ increases to 35°.

Key words: Combustor;Concentric staged;Multi-point direct injection;Flow characteristic;Periodic boundary;Effusion cooling