Abstract The combustion instability in a propulsion system is a ubiquitous problem. The radial baffles usually installed on the injector faceplate eliminate the combustion instability (acoustic pressure oscillation) in the propulsion system. In this article, the longitudinal baffles are installed on the inner surface of the combustor wall to control the combustion instabilities. The first-order and second-order tangential modes are induced in the experiments. The effects of the parameters of the baffle on the acoustic pressure oscillation in the cylindrical combustor are investigated. The effect of the combustor nozzle on the tangential modes has been systematically investigated. It is concluded that the eigen-frequency and amplitude of the first-order tangential mode decline with the increase in the longitudinal baffle number and height. For the second-order tangential mode, the eigen-frequency and amplitude monotonically increase until a maximum value (four baffles), subsequently decrease with the increase in the baffle number and height. The combustor without the nozzle obtains a lower frequency than that with the nozzle, especially for the low baffle height in the combustor.

中文翻译：

---

内表面挡板对圆柱形燃烧室切向声模的影响

摘要 推进系统中的燃烧不稳定性是一个普遍存在的问题。通常安装在喷油器面板上的径向挡板消除了推进系统中的燃烧不稳定性（声压振荡）。在本文中，纵向挡板安装在燃烧器壁的内表面上，以控制燃烧的不稳定性。实验中引入了一阶和二阶切向模式。研究了隔板参数对圆柱燃烧室声压振荡的影响。已经系统地研究了燃烧器喷嘴对切向模式的影响。得出的结论是，一阶切向模式的特征频率和振幅随着纵向挡板数量和高度的增加而下降。对于二阶切向模式，特征频率和振幅单调增加直到最大值（四个挡板），随后随着挡板数量和高度的增加而减小。不带喷嘴的燃烧室获得的频率低于带喷嘴的燃烧室，特别是燃烧室中的低挡板高度。