Tulip火焰形成过程中的细微结构特性

Characteristics of Fine Structure During Tulip Flame Forming

为揭示预混火焰传播的动力学过程以及Tulip火焰的形成规律,采用高速纹影摄像系统并结合离子电流探测等技术手段,对管道内丙烷-空气预混火焰传播过程中的细微结构进行了实验研究.结果表明,在Tulip火焰形成过程中,伴随着层流火焰向湍流转变以及火焰结构的变化;层流火焰中的小尺寸涡流增大火焰厚度,而随后大尺寸涡流使火焰发生褶皱与分层;Tulip火焰结构的形成是流动与火焰共同作用的结果,它标志着层流向湍流转变的充分发展.

To explore the micro-dynamic behavior of premixed flame propagation and the Tulip flame structure, the premixed propane-alr flame was experimentally studied in a semi-vented pipe. The high-speed schlieren image system and ion current detection technology were used to explore the fine structure and propagation characteristics. The experimental result shows that, during the charge of flame front structure from convex to concave, small scale turbulence begins to appear and plays an important role on flame front, which increases flame front thickness and causes flame structure to change. While large-scale turbulence induces flame distortion and stratification. When Tulip flame structure comes into being, the transition from laminar to turbulent occurs, in conclusion, the flow-flame interaction results in flame structure change. The appearance Tulip flame structure forming indicates the accomlishment of laminar-turbulent transition.