Interaction of Vortex Shedding and Transverse High-Frequency Pressure Oscillations in a Tubular Combustion Chamber
Interaction of Vortex Shedding and Transverse High-Frequency Pressure Oscillations in a Tubular Combustion Chamber
复制标题
管式燃烧室中涡旋脱落和横向高频压力振荡的相互作用
DOI：
10.1115/gt2011-45246
复制
发表时间：
2011
影响因子：
4.7
通讯作者：
N. Noiray
中科院分区：
文献类型：
--
作者：
J. Schwing;T. Sattelmayer;N. Noiray
在过去的二十年里，对预混燃气轮机燃烧室热声稳定性的深入研究使人们对亚千赫范围内纵模的不稳定性有了更好的理解，并开发了热声稳定性分析的预测工具。过去对环形燃烧室中的环向模式也进行了研究，尽管由于实验工作量较大，研究的程度要低得多。实验与数值相结合的方法被广泛应用于低频区域(即声学致密火焰)。然而，这种具有预测能力的实验和数值方法必须开发出来，以也解决高频(HF)制度。本文对高频热声耦合进行了实验研究。研究了圆柱形燃烧室中大气条件下的完全预混旋流稳定火焰。试验台配备了多个动态压力传感器，用于识别和重建燃烧室中的声场。火焰前沿位置的平面信息由Mie散射获得，流场由粒子图像测速仪(PIV)测量。在试验中，燃烧室的第一个横向模式在特定的运行条件下表现出不稳定，这导致了持续的极限环脉动。MIE散射图显示燃烧器出口处有周期性的旋涡脱落。PIV结果提供了有关这些相干剪切层涡旋强度的定量信息。
Intense research on the thermoacoustic stability of premixed gas turbine combustors in the past two decades has led to an improved understanding of instabilities of longitudinal modes in the sub-kHz range and predictive tools for thermoacoustic stability analysis have also been developed. Circumferential modes in annular combustors have been studied in the past as well, even though to a much lower extent due to the high experimental effort. Combined experimental-numerical methods for the low-frequency regime (i.e. acoustically compact flames) are widely used. However, such experimental and numerical approaches with predictive capability have to be developed to also address the high-frequency (HF) regime. An experimental study of HF thermoacoustic coupling is presented in this paper. A fully premixed swirl-stabilized flame at atmospheric condition in a cylindrical combustion chamber is investigated. The test rig is equipped with several dynamic pressure transducers to identify and reconstruct the acoustic field in the combustion chamber. Planar information about the flame front location is obtained from Mie-scattering and the flow field is measured with particle image velocimetry (PIV). In the tests the first transverse mode of the combustion chamber exhibits instability for a particular operating condition, which leads to sustained limit-cycle pulsations. Mie-scattering images reveal periodic vortex shedding at the outlet of the burner. PIV results provide quantitative information on the strength of these coherent shear layer vortices.© 2011 ASME