A series of combustion tests was conducted to control and suppress the initiation of low-frequency instability (LFI) by using fuel inserts, through which a small step appeared gradually because of differences in the regression rates of the two materials; polymethyl methacrylate and high-density polyethylene. This small step acts as an artificial block that causes slight changes to the flow characteristics of small vortices generated near the fuel surface. The results show that using a fuel insert delayed the LFI occurrence. In addition, the location of the fuel insert played an important role in determining the level of LFI suppression as well as the phase difference between the combustion pressure $p^{\prime }$ and heat release $q^{\prime }$. Properly locating two fuel inserts simultaneously in the axial direction completely changed the phase difference to $\pi /2$, which caused the LFI to disappear completely.

进行了一系列燃烧试验，以控制和抑制通过使用燃料插件引起的低频不稳定性（LFI）的发生，由于两种材料的回归速度不同，通过这种燃烧逐渐出现了一个小台阶。聚甲基丙烯酸甲酯和高密度聚乙烯。这个小台阶充当了人造的障碍物，导致燃料表面附近产生的小涡流的流动特性略有变化。结果表明，使用燃油插件延迟了LFI的发生。此外，燃料插入件的位置在确定LFI抑制水平以及燃烧压力之间的相位差方面起着重要作用。$p^{\prime }$ 和散热 $q^{\prime }$。在轴向上同时正确定位两个燃油插件，将相位差完全更改为$\pi /2$，这导致LFI完全消失。