Xu Zhuangzhuang, Deng Haoxin, Wen Xiaoping, Wang Fahui, Chen Guoyan, Yan Mengmeng, Wei Shengnan
School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo454003, PR China.
ACS Omega. 2023 Jan 11;8(3):2953-2964. doi: 10.1021/acsomega.2c05553. eCollection 2023 Jan 24.
The combustion characteristics of premixed methane-air flames in a half-open tube with a two-sided 45° branch structure at different ignition positions were investigated by experiments and large eddy simulations. The numerical results were compared with the experimental results to verify the correctness of the model. The results show that the simulation results are highly consistent with the experiment. This study provides a basic understanding of the effects of the branch tube structure and the ignition position on flame dynamics. When the flame propagates to the branch interface, it forms a symmetrical vortex structure at the branch tube with the opposite rotation direction. When the ignition position is at IP0 and IP900, the maximum overpressures obtained in the experiment are 10.1 and 10.7 kPa, respectively, and 9.2 and 10.4 kPa in the simulation, respectively. At IP0, the Karlovitz number indicating the interaction intensity between the flame surface and the turbulence during flame propagation is a maximum of 9.2 and a minimum of 0.04. The premixed flame has a folded small flame, a corrugated small flame, and a thin reaction zone.
通过实验和大涡模拟研究了在具有双侧45°分支结构的半开管中不同点火位置的预混甲烷-空气火焰的燃烧特性。将数值结果与实验结果进行比较以验证模型的正确性。结果表明模拟结果与实验高度一致。本研究提供了对分支管结构和点火位置对火焰动力学影响的基本理解。当火焰传播到分支界面时，在分支管处形成旋转方向相反的对称涡结构。当点火位置在IP0和IP900时，实验中获得的最大超压分别为10.1和10.7 kPa，模拟中分别为9.2和10.4 kPa。在IP0处，表明火焰传播过程中火焰表面与湍流相互作用强度的卡尔洛维茨数最大为9.2，最小为0.04。预混火焰具有折叠小火焰、波纹小火焰和薄反应区。
