The Effect of Confinement on the Structure and Dynamic Response of Lean-Premixed, Swirl-Stabilized Flames
The Effect of Confinement on the Structure and Dynamic Response of Lean-Premixed, Swirl-Stabilized Flames
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DOI：
10.1115/1.4031885
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发表时间：
2015-06
影响因子：
1.5
通讯作者：
Alexander J. De Rosa;S. Peluso;B. Quay;D. Santavicca
中科院分区：
文献类型：
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作者：
Alexander J. De Rosa;S. Peluso;B. Quay;D. Santavicca
通过实验研究了三个燃烧室中的火焰，每个燃烧室具有不同的直径，因此具有不同的侧向约束程度，从而研究了火焰-壁面相互作用对稀薄预混旋流稳定火焰强迫响应的影响。当使用喷管直径相对于燃烧室直径计算时，测试的约束比分别为0.5、0.37和0.29。利用火焰图像和测量的火焰传递函数，在广泛的操作条件下研究和概括了限制的影响。在强迫和非强迫情况下，禁闭的主要影响是火焰结构的改变。这种影响是用参数Lf，Cohr/Dcomb来捕捉的，该参数描述了在每个燃烧室尺寸中火焰与壁面相互作用的变化程度。测量的火焰传递函数数据作为限制的函数，然后通过斯特劳哈尔数进行推广。来自两个较大燃烧室的数据通过将斯特劳哈尔数乘以限制比来折叠，以说明燃烧室内的流动膨胀率和对流速度的变化。传递函数极值的趋势也通过在限制的情况下检查它们和通过使用火焰图像来评估。火焰波动结构的变化也被认为是由于限制的增加。版权所有©2015，ASME
The effect of flame-wall interaction on the forced response of a lean-premixed, swirl-stabilized flame is experimentally investigated by examining flames in a series of three combustors, each with a different diameter and therefore a different degree of lateral confinement. The confinement ratios tested are 0.5, 0.37 and 0.29 when calculated using the diameter of the nozzle relative to the combustor diameter. Using both flame images and measured flame transfer functions, the effect of confinement is investigated and generalized across a broad range of operating conditions. The major effect of confinement is shown to be a change in flame structure in both the forced and unforced cases. This effect is captured using the parameter Lf,CoHR/Dcomb, which describes the changing degree of flame-wall interaction in each combustor size. The measured flame transfer function data, as a function of confinement, is then generalized by Strouhal number. Data from the two larger combustors is collapsed by multiplying the Strouhal number by the confinement ratio to account for the flow expansion ratio and change in convective velocity within the combustor. Trends at the transfer function extrema are also assessed by examining them in the context of confinement and by using flame images. A change in the fluctuating structure of the flame is also seen to result from an increase in confinement.Copyright © 2015 by ASME