Lean combustion has the promise of significantly reducing NOx emissions, but the accompanying increased danger of global extinction, referred to here as blow-off, needs to be addressed. Lean blow-off (LBO) limits play an important role in establishing the combustor operating envelope. From an engineering perspective, experimental investigations focusing on establishing a model to correlate LBO limits of spray flames for various burner geometries and operating conditions have been carried out.^1–6 Whereas the effect of volatility of multi-component fuels on flame blow-off has been investigated extensively,¹ the effect of volatility of single-component fuels for identical flow and burner conditions has received less attention. Additionally, little information is available on the structure of spray flames at conditions near blow-off, which can help not only with designing combustors with better stability limits, but also promote our fundamental understanding of a challenging phenomenon affected by a range of factors including turbulence, kinetics, and phase change. Although the structure of swirl spray flames has been studied from the perspective of droplet velocities and global stability,^7,8 further work is needed to extend such data to conditions very close to blow-off.

中文翻译：

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吹气时旋转喷雾火焰的测量

稀薄燃烧有望显着减少NOx排放，但是必须解决随之而来的全球灭绝危险的增加，在这里被称为排放。精益排污（LBO）限制在建立燃烧室工作范围方面起着重要作用。从工程的角度来看，已经进行了旨在建立模型以使各种燃烧器几何形状和运行条件与喷雾火焰的LBO限值相关的实验研究。^1-6已广泛研究了多组分燃料的挥发性对火焰排放的影响，¹在相同的流量和燃烧器条件下，单组分燃料的挥发性影响很少受到关注。此外，在吹气附近条件下几乎没有关于喷雾火焰结构的信息，这不仅有助于设计具有更好稳定性极限的燃烧器，而且还有助于我们对受湍流等多种因素影响的具有挑战性的现象有基本的了解。 ，动力学和相变。尽管已从液滴速度和整体稳定性的角度研究了旋流喷溅火焰的结构，但仍需要进行^7,8的进一步工作才能将这些数据扩展到非常接近喷吹的条件。