Symmetric and nonsymmetric flame spread between parallel plates of thick combustible solid
Symmetric and nonsymmetric flame spread between parallel plates of thick combustible solid
复制标题
厚可燃固体平行板之间的对称和非对称火焰传播
DOI：
10.1080/00102202.2018.1534838
复制
发表时间：
2018
影响因子：
1.9
通讯作者：
Yuji Nakamura
中科院分区：
文献类型：
--
作者：
Tsuneyoshi Matsuoka;Satoshi Murakami;Takuya Yamazaki;Yuji Nakamura
为了确定对称破缺现象的发生条件，对火焰沿平行可燃板蔓延进行了数值模拟。同时求解气相的二维、与时间相关的守恒方程以及与固相的一维热传导耦合的一步全局反应。成功地模拟了具有两个前缘的火焰蔓延，并在不同的流速和通道高度下检查了其行为。基于前缘的时间历程，除了熄灭之外，模拟的火焰行为还分为三种模式：对称、非对称和振荡。总结了这些模式的发生条件。结果表明，标量耗散率过高引起的局域消光是对称性破缺的关键过程。由于狭窄通道内火焰共存不稳定，因此会发生局部熄灭，以达到系统燃烧的稳定状态。
To identify the occurrence conditions of a symmetry-breaking phenomenon, numerical simulations of flame spread along parallel, combustible plates are performed. Two-dimensional, time-dependent conservation equations for gas-phase with a one-step global reaction coupled to one-dimensional heat conduction for the solid-phase are simultaneously solved. The flame spread having two leading edges was successfully simulated and the behaviors were examined under various flow velocities and channel heights. Based on the time histories of the leading edges, the simulated flame behaviors are distinguished into three modes: symmetric, asymmetric and oscillation, in addition to the extinction. The occurrence conditions of those modes are summarized. The results indicate that the local extinction caused by an excess of the scalar dissipation rate is a key process of the symmetry-breaking. Since coexistence of flames in narrow channel is unstable, the local extinction occurs to achieve a stable state for the system to burn.