GOALI: Experimental and Computational Study of Bluff-body Flame Stabilization with Nonhomogeneous Upstream Mixing

GOALI：非均匀上游混合钝体火焰稳定的实验和计算研究

• 批准号: 0553504
• 负责人: Baki Cetegen
• 金额: --
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0553504&HistoricalAwards=false
• 关键词: GOALI; Experimental; Computational; Study; Bluff

Award AbstractProposal Number: CTS- 0553504 Principal Investigator: Cetegen, Baki M.Institution: University of ConnecticutProposal Title: GOALI: Experimental and Computational Study of Bluff-Body Flame Stabilization with Nonhomogeneous Upstream MixingIn many practical combustion devices, including aircraft augmentors, flame holding occurs in a high speed turbulent vitiated flow via bluff-bodies placed just downstream of fuel injectors. Significant spatial and temporal variations in mixture composition are expected in the flame stabilization region. There have been numerous experimental studies on fully premixed or nonpremixed flames anchored either by bluff bodies or swirling flow, and separate studies of flame propagation in mixture composition gradients. However, there have been no comprehensive investigations of flame stability in regions with both composition gradients and recirculating hot products, despite their relevance to flame holding in aircraft propulsion systems. The intellectual merits of this project involve a detailed experimental investigation of bluff-body stabilized partially-premixed flames in high velocity flows and a complementary computational effort on flame dynamics and stability. The goal of this work is to improve fundamental understanding of flame propagation in recirculating, partial-premixed flows, to assess model accuracy and to examine reduced order models for predicting flame stabilization. The results of this study are directly applicable to aircraft augmentors, which currently use bluff-body stabilization, but will also be broadly applicable to new combustor designs for hydrogen based syngas fuels, which may require enhanced bluff-body stabilization for fuel flexible operation. Detailed laser diagnostic techniques will be applied to develop an in-depth understanding of local conditions leading to flame blow-off at high velocities, and effects of mixture non-uniformities on the onset of flame blow-off and on flame structure prior to blow-off. The experiments will be performed in a planar two dimensional configuration, and the measurement techniques will include velocity imaging, flame structure imaging through laser-induced fluorescence, and upstream profiling of mixture composition. Thorough documentation and control of boundary conditions will be emphasized for compatibility with numerical simulations. Computational modeling of the geometries studied experimentally will be carried out by our GOALI partner at the United Technologies Research Center (UTRC). Unsteady numerical simulations of bluff-body flame holding will be completed for the same cases studied experimentally. The goal will be to assess the capabilities of these simulations to capture flame propagation in stratified flows and to develop extensions of the numerical approach to partially-premixed flame stabilization. The broader scientific impact of this research will be a better fundamental understanding of flame propagation in partially-premixed flows with recirculation. This has direct impact on the design of industrial devices such as augmentors for aircraft engines, but also expands understanding of basic flame behavior in turbulent flows that could be broadly applicable to improved combustor design for new fuels. The project will facilitate training of two graduate students. By working directly with UTRC, these students will gain experience in this field and they will contribute to the U.S. competitiveness in the area of advanced propulsion system design.This project is co-funded by the Combustion and Plasma Systems Program and the Grant Opportunities for Academic Liaison with Industry (GOALI) Program.

奖项摘要建议编号：CTS-0553504首席研究员：Cetegen，Baki M.机构：康涅狄格大学建议标题：GALI：上游非均匀混合钝体火焰稳定的实验和计算研究在许多实际燃烧设备中，包括飞机增强器，火焰保持发生在高速湍流中，通过放置在喷油器下游的钝体来实现火焰稳定。在火焰稳定区，混合气成分在空间和时间上都有显著的变化。已有大量关于钝体或旋流锚定的完全预混或非预混火焰的实验研究，以及关于火焰在混合物组成梯度中传播的单独研究。然而，在成分梯度和循环热产品的区域，尽管它们与飞机推进系统中的火焰保持有关，但还没有全面的火焰稳定性调查。该项目的智能优点包括对高速流动中钝体稳定部分预混火焰进行了详细的实验研究，并对火焰动力学和稳定性进行了补充计算。这项工作的目的是提高对循环、部分预混流动中火焰传播的基本理解，评估模型的准确性，并检验用于预测火焰稳定的降阶模型。这项研究的结果直接适用于目前采用钝体稳定的飞机增压器，但也将广泛适用于氢基合成气燃料的新燃烧室设计，这些设计可能需要增强钝体稳定以实现燃料的灵活操作。将应用详细的激光诊断技术，深入了解导致高速火焰熄灭的局部条件，以及混合物不均匀对火焰熄灭开始和熄灭前火焰结构的影响。实验将在平面二维结构中进行，测量技术将包括速度成像、通过激光诱导荧光的火焰结构成像以及混合物成分的上游轮廓。为了与数值模拟兼容，将强调对边界条件的全面记录和控制。我们在联合技术研究中心(UTRC)的GOALI合作伙伴将对实验研究的几何图形进行计算建模。对于实验研究的相同情况，将完成钝体火焰保持的非定常数值模拟。目标是评估这些模拟捕捉分层流动中火焰传播的能力，并开发部分预混火焰稳定的数值方法的扩展。这项研究的更广泛的科学影响将是更好地从根本上理解有再循环的部分预混流动中的火焰传播。这对飞机发动机增压器等工业设备的设计有直接影响，但也扩大了对湍流中基本火焰行为的理解，可以广泛适用于新燃料的改进燃烧室设计。该项目将促进两名研究生的培训。通过与UTRC的直接合作，这些学生将获得这一领域的经验，他们将为美国在先进推进系统设计领域的竞争力做出贡献。该项目由燃烧和等离子系统计划和与工业的学术联系资助机会计划(GOALI)共同资助。