Study of Interacting Turbulent Flames Using Direct Numerical Simulation and Laser Diagnostics

使用直接数值模拟和激光诊断研究相互作用的湍流火焰

• 批准号: EP/F028741/1
• 负责人: Nedunchezhian Swaminathan
• 金额: $ 42.86万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF028741%2F1
• 关键词: Study; Interacting; Turbulent; Flames; Using

Emissions legislation is becoming ever more stringent and the conventional combustion technologies are incapable of meeting the low ppm levels set by the new legislation. Thus, alternative technologies need to be found and the lean burn concepts have the ability to meet the standards but the ignitability and flame stability of lean premixtures need to be understood clearly. However, lean premixed flames are prone to thermo--acoustic instabilities, because of their high sensitivity to even small scale variations in the fluid dynamic and thermo--chemical state of the mixture. It is becoming clear that interacting flames are a dominant mechanism for creating thermo--acoustic oscillations in lean premixed combustion. Premixed combustion is often more difficult to simulate than nonpremixed combustion, because of the propagation of reacting surfaces in premixtures, with the consequence that engineering models for turbulent premixed combustion are significantly less well developed than those for nonpremixed combustion. A major unsolved problem is to provide a satisfactory description of the small scale interactions between reacting surfaces, within a flame brush, which form the major mechanism for limiting the growth of reacting surface area. Because of this fundamental limitation, existing models are not well adapted to describe the large scale flame-flame interactions that give rise to pressure variations and thermo-acoustic instabilities in combustion chambers.In the present work, we propose to investigate the mutual interaction between flames at a fundamental level using direct numerical simulation and laser diagnostics. In the configuration of twin ``V'' flames considered here the interaction process is controlled by the upstream turbulence and yields a sufficiently long interaction time for statistical sampling in experiments. This geometry is akin to burner--to--burner interaction process inthe annular combustor of a gas turbine engine, and the interaction process to be simulated is considered to be a valid representation of behaviour in turbulent flames. The expected outcome from this work is a close understanding of processes occurring during interaction between flames, leading to development of a revised model for premixed turbulent combustion, containing a physically valid description of processes limiting growth of flame surface area, and with a capability to simulate large scale flame-flame interactions.

排放法规变得越来越严格，传统的燃烧技术无法满足新法规规定的低ppm水平。因此，需要找到替代技术，稀燃概念有能力满足标准，但稀预混物的可燃性和火焰稳定性需要清楚地了解。然而，贫油预混火焰易于发生热声不稳定性，因为它们对混合物的流体动力学和热化学状态的甚至小尺度的变化都很敏感。在稀薄预混燃烧中，相互作用的火焰是产生热声振荡的主要机理。预混燃烧通常比非预混燃烧更难模拟，因为预混物中反应表面的传播，其结果是湍流预混燃烧的工程模型明显不如非预混燃烧的工程模型完善。一个主要的未解决的问题是提供一个令人满意的描述反应表面之间的小规模的相互作用，在火焰刷，形成的主要机制，限制反应表面积的增长。由于这一根本性的限制，现有的模型不能很好地适应于描述大规模的火焰火焰相互作用，引起的压力变化和热声不稳定性在燃烧室中，在目前的工作中，我们建议调查火焰之间的相互作用，在一个基本的水平，使用直接数值模拟和激光诊断。在这里考虑的双“V”形火焰的配置中，相互作用过程由上游湍流控制，并产生足够长的相互作用时间用于实验中的统计采样。这种几何形状类似于燃气涡轮机发动机环形燃烧室中的燃烧器-燃烧器相互作用过程，所模拟的相互作用过程被认为是湍流火焰行为的有效表示。从这项工作的预期成果是一个密切的理解过程中发生的火焰之间的相互作用，导致发展的预混湍流燃烧的修订模型，包含一个物理上有效的描述过程限制火焰表面积的增长，并具有模拟大规模火焰火焰相互作用的能力。

项目成果

Geometrical Properties and Turbulent Flame Speed Measurements in Stationary Premixed V-flames Using Direct Numerical Simulation

• DOI: 10.1007/s10494-010-9284-1
• 发表时间: 2011-12
• 期刊: Flow, Turbulence and Combustion
• 作者: T. Dunstan;N. Swaminathan;K. Bray;R. Cant

The Effects of Non-Unity Lewis Numbers on Turbulent Premixed Flame Interactions in a Twin V-Flame Configuration

非统一路易斯数对双 V 型火焰结构中湍流预混火焰相互作用的影响

• DOI: 10.1080/00102202.2013.763801
• 发表时间: 2013
• 期刊: Combustion Science and Technology
• 影响因子: 1.9
• 作者: Dunstan T

Erratum to: Geometrical Properties and Turbulent Flame Speed Measurements in Stationary Premixed V-flames Using Direct Numerical Simulation

勘误表：使用直接数值模拟测量静态预混 V 型火焰的几何特性和湍流火焰速度

• DOI: 10.1007/s10494-010-9304-1
• 发表时间: 2010
• 期刊: Flow, Turbulence and Combustion
• 作者: Dunstan T

Prediction of Noise Source for an Aeroengine Combustor

• DOI: 10.2514/6.2011-2913
• 发表时间: 2011-06
• 作者: Y. Liu;A. Dowling;N. Swaminathan;T. Dunstan;R. Morvant;M. Macquisten;L. Caracciolo

Spatial correlation of heat release rate and sound emission from turbulent premixed flames

湍流预混火焰的热释放率和声发射的空间相关性

• DOI: 10.1016/j.combustflame.2012.03.003
• 发表时间: 2012
• 期刊: Combustion and Flame
• 影响因子: 4.4
• 作者: Liu Y