阻尼环对固体火箭发动机热声振荡的影响

The suppression characteristics of thermoacoustic pressure oscillation is systematically investigated to effectively solve the thermoacoustic pressure oscillation in a propulsion system. For solid rocket motors (SRM), an experimental system with a flat flame cylindrical combustion chamber was designed. According to the experimental system, the influences of the inhibiter ring and its installation position in combustion chamber on thermoacoustic pressure oscillation were experimentally studied, and the influence characteristics were verified through theoretical calculation. The results show that a first-order pressure oscillation with a frequency of 115 Hz and an amplitude of 119 dB is excited in the combustion chamber without inhibiter ring. After the inhibiter ring is installed, the amplitude of the first-order pressure oscillation is reduced to 81 dB, which is reduced by about 32%, but at the same time, a weaker high-order pressure oscillation is also excited. As the inhibiter ring moves towards the outlet boundary of combustion chamber, the amplitude of the first-order pressure oscillation is further decreased by 13%, while the amplitude of the high-order pressure oscillation increases slightly. The theoretically calculated results are in good agreement with the experimental results, indicating that the inhibiter ring increases the damping of the system, thereby effectively suppressing the thermoacoustic pressure oscillation. And the inhibiter ring near the outlet boundary has greater damping, and the suppression effect is more obvious.