Study on the acoustic field characters of a flame tube model of an annular combustion chamber

Combustion chamber is a core component of the hot section parts of aero engines, since it works under high-temperature and strong-noise circumstance for a long term, its lifespan is relative low and failure rate is relative high. The vibration generated by unstable combustion in the combustion chamber is very serious and the vibration generate noise, the vibration and noise will cause acoustic fatigue damage, thus affect the lifespan of the combustion chamber. According to the requirements of the integrated program on the design of aero engine structure, the structural fatigue prediction and lifespan analysis of combustion chamber are the critical issues in engine design, especially with the advent of new concepts like high efficiency and low pollution, design of new type combustion chamber is becoming more and more important. The present paper elaborated on the basic theory of cavity acoustic mode, analyzed the characteristics of acoustic field of flame tube model of an annular combustion chamber based on the FEM and BEM, and measured the open acoustic modes of dual wall cylinder modes with the experimental approach.