Effect of the Inner Surface Baffles on Acoustic Characteristics in the Combustion Chamber

Abstract

Purpose: One of the issues with combustion chambers is combustion instability, which affects the performance of the system. The influence of various baffle designs on the acoustic characteristics of the combustion chamber is investigated numerically in this work utilizing linear acoustic analysis. An industrial combustion chamber is considered, and transverse baffles are used to control the combustion instability. Methods: The effects of length, height, and baffle blades on acoustic characteristics are simulated by using ABAQUS 6.14. The quality of each baffle configuration is determined by examining their influence on the essential parameters such as natural frequency shift and damping factor. Modal and harmonic analyses for the acoustic field are conducted to investigate the effect of baffles installed in the combustion chamber. Results: According to the obtained results, increasing the baffle blades' height increases the damping factor in the first two circumferential (tangential) modes. Increasing the blade length also increases the damping factor in tangential modes but has a more negligible effect. Increasing the number of baffle blades in proportion to the mode number can increase or decrease the damping factor. Conclusion: This research is done based on the acoustic analysis of the combustion chamber to design passive control equipment such as baffles and acoustic resonators.