%A KANG Zhongtao, ZHANG Xinqiao, CHENG Peng, LI Qinglian, WANG Zhenguo %T Influence of Gas Core Dimension on Self-pulsation of Gas-liquid Swirl Coaxial Injector %0 Journal Article %D 2014 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2014.0023 %P 3283-3292 %V 35 %N 12 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_15494.shtml} %8 2014-12-25 %X

To understand the influence of gas core dimension on self-pulsation characteristics of gas-liquid swirl coaxial injector, non-reactive spray experiments are conducted with water and air at atmospheric pressure. The spray morphology of gas-liquid swirl coaxial injectors with different gas core dimensions is investigated while self-pulsation happens. Self-pulsation morphology changes with gas core dimension; the spray looks like a Christmas tree with a large gas core, and a string of pearl with small gas core. The results indicate that gas core dimension significantly affects the self-pulsation mechanism, which in turn varies the influence of recess length on self-pulsation. Self-pulsation frequency varies complicatedly with recess length when gas core dimension is large enough. But with a small gas core, the recess length can hardly change the frequency of self-pulsation. In general, self-pulsation frequency is in the range of 2-4 kHz, which corresponds to frequency range of first transrerse mode in combustion instability. Namely, self-pulsation can trigger combustion instability.