High-Frequency Thermoacoustic Modulation Mechanisms in Swirl-Stabilized Gas Turbine Combustors: Part Two — Modeling and Analysis
High-Frequency Thermoacoustic Modulation Mechanisms in Swirl-Stabilized Gas Turbine Combustors: Part Two — Modeling and Analysis
复制标题
涡流稳定燃气轮机燃烧室中的高频热声调制机制：第二部分 - 建模与分析
DOI：
10.1115/gt2016-57500
复制
发表时间：
2016
影响因子：
1.5
通讯作者：
T. Sattelmayer
中科院分区：
文献类型：
--
作者：
T. Hummel;F. Berger;M. Hertweck;B. Schuermans;T. Sattelmayer
本文研究了旋流稳定燃气轮机燃烧室的高频热声不稳定性。从理论上讨论了周期性火焰位移和火焰形状变形的驱动机理，并从第一性原理推导了相应的火焰传递函数。这些线性反馈模型然后通过实验室规模的旋流稳定燃烧器结合本联合出版物的第一部分进行评估。为此，利用该模型对该燃烧室设备的全部工作点进行了热声表征。具体来说，计算了第一横模的增长率，并将其与实验得到的压力幅值作为热声稳定性的指标进行了比较。表征是基于一种依赖于声学守恒方程频域公式的混合分析方法，其中可以直接考虑非均匀温度场和分布的热声源项/火焰传递函数。确定了火焰位移和变形驱动机制的相对贡献-即它们对总驱动的重要性。此外，还揭示了涡旋稳定燃气轮机燃烧室内高频横向声不稳定性产生的促进/抑制条件。
This paper deals with high-frequency thermoacoustic instabilities in swirl-stabilized gas turbine combustors. Driving mechanisms associated with periodic flame displacement and flame shape deformations are theoretically discussed, and corresponding flame transfer functions are derived from first principles. These linear feedback models are then evaluated by means of a lab-scale swirl-stabilized combustor in combination with part one of this joint publication. For this purpose, the models are used to thermoacoustically characterize a complete set of operation points of a this combustor facility. Specifically, growth rates of the first transversal modes are computed, and compared against experimentally obtained pressure amplitudes as an indicator for thermoacoustic stability. The characterization is based on a hybrid analysis approach relying on a frequency domain formulation of acoustic conservation equations, in which non-uniform temperature fields and distributed thermoacoustic source terms / flame transfer functions can be straightforwardly considered. The relative contribution of flame displacement and deformation driving mechanisms — i.e. their significance with respect to the total driving — is identified. Furthermore, promoting/ inhibiting conditions for the occurrence of high frequency, transversal acoustic instabilities within swirl-stabilized gas turbine combustors are revealed.