High-Frequency Transverse Combustion Instabilities in Multinozzle Can Combustors with Perforated Liners

The prediction and control of high-frequency transverse combustion instability in can combustion chambers has received widespread interest in recent years along with the application of advanced industrial gas turbines. This study establishes a three-dimensional theoretical framework to explore the combustion instability attributes of high-frequency transverse modes under various operating conditions while accounting for the influence of the nozzle’s radial position. It indicates that the first-order azimuthal mode is determined by the outer nozzle, whereas the first-order radial mode is mainly affected by the inner nozzle, due to spatial coincidence of acoustic pressure antinodes with nozzle positions. Meanwhile, an examination of the impact of perforated liners on transverse modes is performed with the aim of suppressing unstable modes and finding the control mechanism involved. Results show that in comparison with the first-order azimuthal mode, the first-order radial mode is more sensitive to the parameters of the perforated liner. The discrepancy can be attributed to the acoustic dissipation and gain for transverse modes with different frequencies and pressure moduli. The present work contributes to current understanding of the varied influences of flame responses in nozzles and their radial dependencies on transverse modes. Moreover, it elucidates the complex mechanisms of suppressing transverse combustion instability within can combustion chambers using perforated liners.