This paper shows the importance of considering the thermal state of a combustor to investigate or predict its thermoacoustic stability. This aspect is often neglected or regarded as less important than the effect of the operating parameters, such as thermal power or equivalence ratio, but under certain circumstances it can have a dramatic influence on the development of the instabilities. The paper presents experimental results collected from a combustor featuring a lean swirl-stabilized flame exhibiting thermoacoustic instability at some operating conditions. It is shown that this instability is caused by a change of the flame topology that is induced by the progressive increase of the wall temperature with the thermal power. This dependence of the instability on wall temperature leads to inertial effects and hysteresis when the operating condition is changed dynamically. A low-order model of the system reproducing this remarkable dynamics is proposed and validated against the experimental data.

本文显示了考虑燃烧器的热状态以研究或预测其热声稳定性的重要性。通常不考虑或认为这方面不如操作参数（例如火力或当量比）的影响重要，但在某些情况下，它可能对不稳定性的发展产生重大影响。本文介绍了从燃烧室收集的实验结果，该燃烧室具有稀薄的旋流稳定火焰，在某些操作条件下表现出热声不稳定性。结果表明，这种不稳定性是由壁面温度随热功率的逐渐升高引起的火焰拓扑变化引起的。当操作条件动态变化时，这种不稳定性对壁温的依赖性会导致惯性效应和磁滞现象。提出了再现这种非凡动力的系统的低阶模型，并针对实验数据进行了验证。