Analysis of flow and density oscillations in a swirl-stabilized flame employing highly resolving optical measurement techniques
Analysis of flow and density oscillations in a swirl-stabilized flame employing highly resolving optical measurement techniques
复制标题
采用高分辨率光学测量技术分析涡流稳定火焰中的流量和密度振荡
DOI：
10.1007/s00348-013-1622-3
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发表时间：
2013
影响因子：
2.4
通讯作者：
Thomas Leitgeb
中科院分区：
文献类型：
--
作者：
A. Fischer;J. König;J. Czarske;Johannes Peterleithner;J. Woisetschläger;Thomas Leitgeb
现代飞机发动机在核心空气质量流量减少的情况下运行，这对高效且最重要的是稳定的燃料燃烧具有挑战性。这里研究的可变几何燃烧器允许稳定的稀薄燃烧，空气质量流量比固定几何燃烧器低。为了进一步优化这种燃烧器，必须对发生的火焰不稳定性进行研究。这就要求光学测量技术具有高测量速率和对火焰发光不敏感。在流速测量方面，调频多普勒全球测速仪（FM-DGV）满足了这些要求。在变几何燃烧器的旋流稳定火焰中，用FM-DGV获得了高达2.5 kHz的速度场光谱。例如，在旋转火焰中发现了约255hz的共振峰，这也发生在激光干涉振动测量法的密度测量中。对速度和密度振荡的综合分析为火焰流动的物理学提供了新的见解。
Modern aircraft engines operate with a reduced core air mass flow, which is challenging regarding an efficient and most of all stable combustion of fuel. A variable geometry burner investigated here allows a stable lean combustion with lower air mass flow rate than with a fixed geometry. In order to optimize such burners further, the occurring flame instabilities have to be investigated. This requires optical measurement techniques with a high measurement rate and an insensitivity regarding flame glow. Concerning flow velocity measurements, the frequency modulated Doppler global velocimetry (FM-DGV) fulfills these demands. In the swirl-stabilized flame of the variable geometry burner, spectra up to 2.5 kHz of the flow velocity field were obtained with FM-DGV. For example, a resonance peak at about 255 Hz was identified in the swirled flame, which also occurs in complementing density measurements by laser interferometric vibrometry. The combined analysis of velocity and density oscillations offer new insights into the physics of flame flows.