A key challenge for the gas turbine combustors is to satisfy stringent emission standards while maintaining high efficiency towards the production of power or thrust. The pollutant formation, especially the NO_x emission, can be reduced by using lean fuel–air mixture.^1,2 However, in the lean regime of operation, the combustors are prone to a couple of major problems, namely, combustion instability and lean blowout (LBO). In the present study, we focus on the transition to blowout in a laboratory-scale combustor. Blowout, which is classically described as a loss of static stability, occurs when the flame inside a combustor gets blown off or extinguished.³ At low equivalence ratios, there is always a possibility of local flame extinction due to high instantaneous strain rate⁴ which leads to blowout. Blowout is a serious problem in both land-based gas turbines and aero-engines. As a conservative estimate, an operator needs to maintain a safe operational range in order to avoid the occurrence of blowout. However, a recent development of partially premixed combustors is promising for the land-based gas turbines so as to extend the blowout limit towards more lean mixture.^5,6 In case of aero-engines, the fuel is injected close to the actual combustion zone, which makes the flame partially premixed. One of the damaging consequences of blowout in power producing gas turbines is the expensive shutdown of a combustor while LBO in aero-engines may cause fatal accidents. Further, such an event increases the maintenance cost and reduces the engine life.

中文翻译：

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在反应器混合气变化的情况下，对稀薄燃烧室中稀薄燃烧之前的火焰行为和动力学进行研究，以早期发现稀薄燃烧

燃气轮机燃烧室的主要挑战是要满足严格的排放标准，同时又要保持产生动力或推力的高效率。污染物的形成，尤其是NO _X排放，可以通过使用贫燃料-空气混合物被减小。^1,2但是，在稀薄运行状态下，燃烧器容易出现两个主要问题，即燃烧不稳定性和稀薄吹出（LBO）。在本研究中，我们着重于实验室规模燃烧器向井喷的过渡。爆燃，通常被描述为静态稳定性的损失，发生在燃烧器内的火焰被吹散或熄灭时。³在低当量比的情况下，由于高瞬时应变率⁴导致爆裂，总是存在局部熄灭的可能性。在陆基燃气轮机和航空发动机中，井喷都是一个严重的问题。作为保守的估计，操作员需要保持安全的操作范围，以避免发生井喷。然而，部分预混燃烧器的最新发展对于陆基燃气轮机是有希望的，以便将井喷极限扩展到更贫的混合物。^5,6在航空发动机的情况下，将燃料喷射到靠近实际燃烧区的位置，这会使火焰部分地预混。发电燃气涡轮机爆燃的破坏性后果之一是燃烧室的昂贵停机，而航空发动机中的LBO可能会导致致命事故。此外，这样的事件增加了维护成本并缩短了发动机寿命。