Effects of Intrinsic Flame Instabilities On Thermoacoustic Oscillations in Lean Premixed Gas Turbines
Effects of Intrinsic Flame Instabilities On Thermoacoustic Oscillations in Lean Premixed Gas Turbines
复制标题
固有火焰不稳定性对精益预混燃气轮机热声振荡的影响
DOI：
10.1115/1.4053421
复制
发表时间：
2022-01
期刊：
影响因子：
--
通讯作者：
Jiashan Cui
中科院分区：
文献类型：
--
作者：
Fangyan Li;Xiaotao Tian;Minglong Du;Lei Shi;Jiashan Cui
热声不稳定性是航空发动机和火箭发动机研制过程中经常遇到的问题。研究热声不稳定性的基本机理，有助于这类发动机系统的优化设计。建立了基于稀薄预混燃气轮机（LPGT）燃烧系统的热声不稳定性模型。该模型考虑了火焰阵面内禀不稳定性引起的放热纵向分布。基于该模型，研究了不同放热分布和预混气体特征参数（刘易斯数Le、Zeldovich数Pr和Prandtl数Pr）对LPGT系统热声不稳定性行为的影响。结果表明，LPGT系统具有两种不稳定的热声模态。第一个对应于增压室的自然声学模式，第二个对应于燃烧室的自然声学模式。预混气体的特性参数对系统的稳定性有很大的影响，甚至可以使系统从稳定状态转变为不稳定状态。
Thermoacoustic instabilities are commonly encountered in the development of aeroengines and rocket motors. Research on the fundamental mechanism of thermoacoustic instabilities is beneficial for the optimal design of these engine systems. In the present study, a thermoacoustic instability model based on the lean premixed gas turbines (LPGT) combustion system was established. The longitudinal distribution of heat release caused by the intrinsic instability of flame front is considered in this model. Effects of different heat release distributions and characteristics parameters of the premixed gas (Lewis number Le, Zeldovich Number and Prandtl number Pr) on thermoacoustic instability behaviors of the LPGT system are investigated based on this model. Results show that the LPGT system features with two kinds of unstable thermoacoustic modes. The first one corresponds to the natural acoustic mode of the plenum and the second one corresponds to that of the combustion chamber. The characteristic parameters of premixed gases have a large impact on the stability of the system and even can change the system from stable to unstable state.