AI 中文总结
本研究采用欧拉-拉格朗日方法与改进型FGM模型，探究不同旋流数对受限旋流热伴流中空气稀释甲醇喷雾燃烧火焰稳定性、lift-off高度及结构的影响，为低排放燃烧室设计提供依据。
AI 中文摘要
本研究采用旋流热伴流以优化燃料-空气混合效果并稳定火焰，这对设计低排放旋流稳定燃烧室至关重要。本研究在空气稀释甲醇喷雾周围引入受限旋流热伴流，采用欧拉-拉格朗日方法进行多相模拟：通过拉格朗日框架解析分散液相，通过欧拉框架处理连续气相。改进型火焰生成流形（FGM）模型可实现气相反应的精确且计算高效的模拟。本研究采用旋流数（SN）为0.2、0.6、1.0、1.4、2.0和3.0，以评估其对火焰稳定性和自燃的影响。结果显示，旋流数从低升至中等（SN=0.2、0.6、1.0）时，火焰 lift-off 高度升高；当达到临界旋流数（SN=1.0）后，lift-off 高度下降。较大的旋流数还使时间平均火焰结构从尖锐柱状火焰变为均匀扩散的燃烧区域，高旋流数时火焰更紧凑且分布更广。本研究通过颗粒统计、火焰指数、本征正交分解（POD）及平均气相流场分布，详细探究了这些因素对火焰动力学的影响。
英文摘要
This study employs swirling hot coflow to ensure improved fuel-air mixture and stable flame, which are essential for designing low-emission, swirl-stabilized combustors. The present study introduces a swirling confined hot coflow around an air-diluted methanol spray. We have used the Eulerian-Lagrangian approach for multiphase simulation, resolving the dispersed liquid phase via the Lagrangian framework while addressing the continuous gas phase through the Eulerian framework. The Modified Flamelet Generated Manifold (FGM) model facilitates accurate and computationally efficient simulation of gas-phase reactions. The swirl numbers (SN), which are 0.2, 0.6, 1.0, 1.4, 2.0, and 3.0, are employed in this study to evaluate their impact on flame stability and auto-ignition. A higher lift-off height is observed as the swirl number rises from lower to moderate (SN = 0.2, 0.6, and 1.0). It decreases after the lift-off height reaches the critical swirl number (SN=1.0). These large swirl numbers also cause the time-averaged flame structure to change from a sharp columnar flame to an evenly spread combustion region. It also produces a more compact and widely dispersed flame for higher swirl numbers. Particle statistics, Flame Index, proper orthogonal decomposition (POD), and the mean gas-phase flow field distribution are used to study these impacts on flame dynamics in detail.
Journal refApplication in Energy and Combustion Science, 2025, 25, 100361
DOI：10.1016/j.jaecs.2025.100361
