Impacts of Multi-Swirl Interaction Pattern on Self-Excited Instability Combustion Characteristics  

作　　者：JIN Ming LIU Zhannan LU Yudi GE Bing ZANG Shusheng 

机构地区：[1]School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai,200240,China

出　　处：《Journal of Thermal Science》2025年第2期672-688,共17页热科学学报(英文版)

基　　金：the National Science and Technology Major Project(HT-J2019-II-0018-0039)of China for financial support。

摘　　要：Experimental and numerical investigations have been carried out on the effects of multi-swirl interaction patterns on self-excited unstable combustion characteristics based on a five-nozzle can combustor.The multi-swirl interaction patterns include equal swirl intensity interaction and strong-weak swirl interaction.The thermo-acoustic instability characteristics indicate that increasing the central nozzle swirl intensity transforms the interaction pattern from equal swirl intensity interaction to strong-weak swirl interaction,which can significantly weaken the thermo-acoustic coupling effect under low equivalence ratio conditions,and substantially reduce the dynamic pressure amplitude during unstable combustion.The instantaneous flame structures show that the multi-swirl flames exhibit chaotic oscillations under low equivalence ratio conditions.With equivalence ratios greater than 0.71,a clear flame interaction boundary appears,and the flames can exhibit periodic oscillations in a regular structure.However,different interaction patterns result in the completely different phase oscillations in the central and outer flames.The time-averaged flame structures also indicate that strong-weak swirl interaction leads to an increase in the flame angle and a decrease in the flame length for both the central and outer flames,and the variations in the flame angle and length have great impacts on the thermo-acoustic instability mode.The fuel-staging combustion characteristics demonstrate that the instability combustion conditions with a dominant frequency of 100 Hz are greatly broadened by the strong-weak swirl interaction pattern,and the overlapping operating conditions between this mode and other modes are greatly increased.This implies that it is more flexible to adjust the thermo-acoustic unstable mode,which is conducive to the passive suppression of thermo-acoustic instability.

关 键 词：multi-nozzle burner swirl interaction thermo-acoustic instability flame structure fuel-staging 

分 类 号：O35[理学—流体力学]