Effects of cooling flow on the flow structure and acoustic oscillation in a swirl-stabilized combustor. Part II: Acoustic analysis

다국어 초록 (Multilingual Abstract)

The proper orthogonal decomposition (POD) analysis was implemented to extract the acoustic modes from the flow field inside a swirl-stabilized combustor obtained from non-reacting large eddy simulation. The major frequencies and the spatial distribution of fluctuating pressure of dominant POD modes were presented. The first four dominant modes occupied more than 70 % of the total energy of the oscillatory flow fields. Cooling flow injection suppressed the amplitude of pressure fluctuation and tended to dissipate the high-order longitudinal acoustic modes. The dominant acoustic modes observed in the fluctuating pressure field in the case with no cooling flow injection were dissipated or shifted by the injection of cooling flow..