An experimental study of coupling between combustor pressure, fuel/air mixing, and the flame
An experimental study of coupling between combustor pressure, fuel/air mixing, and the flame
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燃烧室压力、燃料/空气混合和火焰耦合的实验研究
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
A. Ratner
中科院分区：
文献类型：
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作者：
D. Kang;F. Culick;A. Ratner
通过研究混合燃料馏分场的响应，研究了施加声振荡影响下的燃料-空气混合行为。混合区内局部燃料混合分数的分布与不稳定和振荡的火焰行为密切相关，而混合区内局部燃料混合分数的分布有望演化为火焰区内的局部等效比。实验采用空气动力稳定非预混燃烧器进行。在这项研究中，声学振荡施加在22、27、32、37和55Hz。用相分辨丙酮PLIF对等温流场和反应流场进行成像，并结合所得的时间和空间不混合量进行分析。并与以往火焰区振荡的测量结果进行了比较。这一比较表明，燃料/空气混合中的局部振荡（数毫米或更小）与火焰的振荡行为密切相关。对于每一个驱动频率，混合气分数在该频率下振荡，但与压力场/火焰强度之间存在微小的相位差，这表明混合气分数振荡可能是这类火焰和燃烧室几何形状振荡行为的主要原因。
Fuel-air mixing behavior under the influence of imposed acoustic oscillations has been studied by investigating the response of the fuel mixture fraction field. The distribution of local fuel mixture fraction inside the mixing zone, which is expected to evolve into the local equivalence ratio in the flame zone, is closely coupled to unstable and oscillatory flame behavior. The Experiment was performed with an aerodynamically-stabilized non-premixed burner. In this study, acoustic oscillations were imposed at 22, 27, 32, 37, and 55Hz. Phase-resolved acetone PLIF was used to image the flow field of both isothermal and reacting flow cases and this data along with the derived quantities of temporal and spatial unmixedness were employed for analysis. The behavior of the unmixedness factor is compared with the previous measurements of oscillations in the flame zone. This comparison shows that local oscillations (of order millimeters or smaller) in fuel/air mixing are closely related to the oscillatory behavior of the flame. For each driving frequency, the mixture fraction oscillates at that frequency but with a slight phase difference between it and the pressure field/flame intensity, indicating that the fuel mixture fraction oscillation are likely the major reason for oscillatory behaviors of this category of flames and combustor geometry.