Experimental studies and modeling of acoustic instabilities in a gas turbine model combustor
Experimental studies and modeling of acoustic instabilities in a gas turbine model combustor
复制标题
燃气轮机模型燃烧室声不稳定性的实验研究和建模
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
J. Driscoll
中科院分区：
文献类型：
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作者：
Yuntao Chen;J. Driscoll
部分预混燃烧具有低NOx排放和高效率的优点。然而，当燃气涡轮机发动机以预混合模式运行时，在燃烧室中产生的声学不稳定性阻碍了这种技术的实际应用。为了帮助设计下一代低排放高效率燃气涡轮机，需要对触发和维持这种不稳定性的物理过程有透彻的了解。在这项工作中，声学不稳定性表现在气体涡轮机模型燃烧室（GTMC），这是在德国航天中心斯图加特由W。Meier和他的同事进行了调查。具体地，GTMC在富燃料条件下用二甲醚（DME）操作。进行了多点压力测量以表征燃烧室的主要不稳定模式。同时平面激光诱导荧光（PLIF）的甲醛（CH2O）和压力测量，然后在持续频率为4 kHz。火焰表面密度，计算从火焰边缘中检测到的PLIF图像，被用作火焰热释放速率的指标，并确定在时间和空间上。最后提出了一个降阶模型来描述所观察到的燃烧不稳定性。该模型的关键预测，如不稳定频率和压力相位差，同意与实验观察。未来的工作将集中在扩展现有的模型，探讨不同的参数对燃烧不稳定性的影响。
Partially premixed combustion has the merits of lower NOx emission as well as higher efficiency. However practical applications of such technology have been hindered by acoustic instabilities generated in combustion chambers when gas turbine engines are operated in premixed mode. A thorough understanding of the physical processes which trigger and sustain this instability needs to be gained to aid the design of next generation low-emission high-efficiency gas turbine engines. In this work, acoustic instabilities manifested in the Gas Turbine Model Combustor (GTMC), which was developed at DLR Stuttgart by W. Meier and colleagues, were investigated. Specifically, the GTMC was operated with dimethyl ether (DME) in a fuel rich condition. Multi-point pressure measurements were carried out to characterize the dominant instability mode of the combustion chamber. Simultaneous Planar Laser-Induced Fluorescence (PLIF) of formaldehyde (CH2O) and pressure measurements were then made at a sustained frequency of 4 kHz. Flame surface densities, calculated from the flame edges detected in the PLIF images, were used as the indicator of flame heat release rate and determined both temporally and spatially. Finally a reduced order model was proposed to describe the observed combustion instability. Key predictions made by this model, such as instability frequency and pressure phase differences, agreed with experimental observations. Future work will focus on expanding present model to explore the effects of varying parameters on the combustion instability.