贫预混燃烧技术是有效降低热NOx排放的途径之一。但是这种燃烧技术遇到的一个普遍问题就是热声耦合振荡现象。热声耦合振荡会干扰燃烧过程，增大污染物的排放，严重时会对整个燃烧系统造成结构性破坏。因此有必要对热声耦合振荡过程进行研究。本文在不同条件下，对旋流预混燃烧热声耦合振荡现象的动态特性进行了实验研究。同时结合理论分析，研究其发生机理，为贫预混燃烧技术的发展提供理论与技术支持。 为了模拟真实燃气轮机燃烧室的运行条件，首先搭建了燃气轮机燃烧动力学实验平台和动态测量系统；实验平台采用动态压力传感器和光谱仪对燃烧过程中的动态压力和放热率脉动进行测量。通过化学自发荧光相同步测量的方法，对周期性火焰脉动进行二维测量，并且对相同步方法的测量误差进行了分析。 分析了不同当量比、热负荷和进出口边界条件下天然气燃烧的动态过程。针对不同工况条件，分析其稳定范围及振荡模态随影响因素的变化规律。结果显示振荡频率随着燃气当量比的减小而有所增加，但是没有发生模态变化。在常压条件、接近贫燃熄火极限时，热声耦合振荡现象消失，压力脉动频率跃升至500 Hz或1000 Hz附近的高频，与喷嘴射流的扰动频率相关。燃烧室出口越接近阻塞条件，燃烧过程的稳定范围越小。同时入口边界位置越接近燃烧段，压力脉动频率越高。热功率变化会影响脉动频率和声压级数值。 对不同当量比和不同燃料组分的合成气燃烧动态过程进行了实验研究，分析了不同工况条件下的振荡模态，以及随影响因素的变化规律，得到了含氢合成气的稳定边界与回火极限。 同时采用线性扰动分析方法对天然气燃烧动态过程进行理论分析，建立相应的火焰模型，对热声耦合振荡现象进行分析与预测，进一步研究了不同条件下旋流预混燃烧的热声耦合振荡模态。

Lean premixed combustion is an effective technology that can reduce NOx emission efficiently. Whenever, the combustion instabilities were common problems which can be met in lean premixed combustion. It may disturb the combustion process and produce the NOx emissions. In some situations, they could destroy the combustion chamber. Therefore, it is essential to study the dynamical processes of combustion oscillations. In the thesis, the experimental studies were conducted to investigate the dynamic processes of lean premixed swirling combustion oscillations. The theoretical analysis was examined to predict the oscillation modes and stabilities of onset combustion oscillations. Firstly, a model combustion chamber and a dynamic measurement system were established. The dynamic pressure transducers were used for measuring pressure perturbations and photomultiplier tube for detecting the heat release perturbation. The relationship between pressure perturbations and heat release perturbation was obtained by phase-locked chemiluminescence measurements. The data acquisition and processing program were developed to realize the real-time processing of the signals. The dynamical flames images can be obtained simultaneously through synchronize system. The error of phase-locked measurement was discussed and the improving methods were suggested. The dynamical processes of natural gas premixed combustion were examined with the varying fuel-air equivalence ratio; power loads and boundary conditions. Under each condition, the equivalence ratio range of stable combustion was obtained and the variations of oscillation modes were analyzed. It was shown that the oscillation frequencies would be increasing with the equivalence ratio decreasing. At the atmosphere pressure, the combustion oscillations will disappear near the lean blow out limits and the frequencies will change in the range between 500 Hz and 1000 Hz, which may be coupled with flow disturbances. The combustion stable range turns into narrow when the outlet is close to the choking conditions. The shorter length of the inlet boundary, the higher frequency of the pressure oscillations. The power loads also have significant influences on the frequencies of oscillations and their amplitudes. The dynamical processes of syngas combustion were examined with different fuel-air equivalence ratio and hydrogen fraction. The information of oscillation modes at different conditions were obtained, and the effects of the variations of fuel components on the combustion oscillation, flashback and extinguish range were discussed. At last, the dynamical processes of natural gas combustion were also theoretical studied by linear perturbation theory. The flame model was established, which can study and predict the combustion instabilities effectively, the oscillation modes were analyzed.