Propagation and generation of acoustic and entropy waves across a moving flame front
Propagation and generation of acoustic and entropy waves across a moving flame front
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DOI：
10.1016/j.combustflame.2016.01.015
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发表时间：
2016-04-01
影响因子：
4.4
通讯作者：
Polifke, Wolfgang
中科院分区：
文献类型：
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作者：
Chen, Lin Strobio;Bomberg, Sebastian;Polifke, Wolfgang
在预混火焰中声波和熵波的传播和产生的分析模型中，耦合上游和下游流动变量的关系通常将火焰视为静止的不连续性。这项工作显示了如何在休息的火焰模型可以歪曲熵波的产生，以及它如何导致矛盾的结果，关于整个火焰的质量和体积流量守恒。这种不一致性可以通过考虑流动扰动耦合关系中火焰的运动来解决。在准一维框架中的分析表明，在当量比扰动的情况下，跨火焰产生的熵波的幅度是一阶马赫数，并来自上游声学和平均热释放率之间的相互作用。对于非理想预混火焰，当量比的波动会引起马赫数主阶熵的扰动。此外，对于移动火焰模型守恒的体积流量在被动，完全预混火焰出现作为一个自然的结果，质量和能量守恒。(C)2016燃烧研究所爱思唯尔公司出版All rights reserved.
In analytical models of the propagation and generation of acoustic and entropy waves across a premixed flame, the relations that couple upstream and downstream flow variables often consider the flame as a discontinuity at rest. This work shows how the model of a flame at rest can misrepresent the generation of entropy waves, and how it leads to paradoxical results concerning the conservation of mass and volume flow rates across the flame. Such inconsistencies can be resolved by taking into account the movement of the flame in the coupling relations for flow perturbations. Analysis in a quasi-1D framework shows that in the absence of perturbations in equivalence ratio, the magnitude of the entropy waves generated across the flame are first order in Mach number and derive from interactions between the upstream acoustics and the mean heat release rate. For non-perfectly premixed flames, fluctuations in equivalence ratio may generate perturbations in entropy of leading order in Mach number. Furthermore, for the moving flame model conservation of volume flow rate across a passive, perfectly premixed flame appears as a natural consequence of mass and energy conservation. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.