Flame structure of nozzles offsetting opposite flows

7th European Thermal-Sciences Conference

Yahagi, Yuji^1 ; Morinaga, Yuichiro^1 ; Hamaishi, Kyosuke^1 ; Makino, Ikuyo^2

Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo

1358548, Japan^1

Tohoku University, 6-6-4 Aramakizi, Aoba-ku, Sendai

9808579, Japan^2

关键词: Counter-flows;    Flame stability;    Flame structure;    Flame zones;    Flow systems;    Methane-air;    Premixed gas;    Velocity difference;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/745/3/032030/pdf
DOI  :  10.1088/1742-6596/745/3/032030

来源: IOP

【 摘 要 】

Effects of vortexes behind flame zone on the flame structures are investigated experimentally by nozzles offsetting opposite flows with 2D laser diagnosis. Methane air premixed gas issued from upper and lower burners with equal flow rate. An imbalanced counter flow is produced to slide the lower burner from the center axis. In our proposed flow system, the vortexes are only formed in the burnt gas region by the shear stress due to the velocity difference between the upper flow and lower flow. Three distinct flames structures, slant flames, edge shape flames, and hyperbolic flames are decided with the offsetting rate and fuel flows composition. The formed vortexes structures changed with the offsetting rate. The vortex formed behind the flame plays an important role for the flame stability.