Since its discovery, the Flameless Combustion (FC) regime has been seen as a promising alternative combustion technique to reduce pollutant emissions of gas turbine engines. This combustion mode is often characterized by well-distributed reaction zones, which can potentially decrease temperature gradients, acoustic oscillations and, consequently NOx emission. However, the application of FC to gas turbines is still not a reality due to the inherent difficulties faced in attaining the regime while meeting all the engine requirements. Over the past years, investigations related to FC have been focused on understanding the fundamentals of this combustion regime, the regime boundaries, its computational modelling, and combustor design attempts. This article reviews the progress achieved so far, discusses the various definitions of the FC regime, and attempts to point the directions for future research. The review suggests that modelling of the FC regime is still not capable of predicting intermediate species and pollutant emissions. Comprehensive experimental databases with conditions relevant to gas turbine combustors are not available, and moreover, many of the current experiments do not necessarily represent the FC regime. By analysing the latest developments in computational modelling, the review points to the most promising approaches for the prediction of reaction zones and pollutant emissions in FC. The lessons learned from previous design attempts provide valuable insights into the design of a successful gas turbine engine operating under the FC regime. The review concludes with some examples where the gas turbine architecture has been exploited to advance the possibilities of FC in gas turbines.

中文翻译：

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无焰燃烧及其对燃气轮机的潜力

自发现以来，无焰燃烧 (FC) 机制一直被视为一种有前景的替代燃烧技术，可减少燃气涡轮发动机的污染物排放。这种燃烧模式通常以分布良好的反应区为特征，这可能会降低温度梯度、声波振荡，从而降低 NOx 排放。然而，由于在满足所有发动机要求的同时获得该制度所面临的固有困难，将 FC 应用于燃气轮机仍然不是现实。在过去的几年中，与 FC 相关的研究一直集中在了解这种燃烧机制的基本原理、机制边界、其计算建模和燃烧室设计尝试上。本文回顾了迄今为止取得的进展，讨论了 FC 制度的各种定义，并试图为未来的研究指明方向。审查表明，FC 制度的建模仍然不能预测中间物种和污染物排放。与燃气轮机燃烧器相关的条件的综合实验数据库不可用，而且，当前的许多实验不一定代表 FC 制度。通过分析计算建模的最新发展，该评论指出了预测 FC 反应区和污染物排放的最有前途的方法。从以前的设计尝试中吸取的经验教训为在 FC 制度下运行的成功燃气涡轮发动机的设计提供了宝贵的见解。