A Simple Model for Wildland Fire Vortex–Sink Interactions
A Simple Model for Wildland Fire Vortex–Sink Interactions
复制标题
荒地火涡-汇相互作用的简单模型
DOI：
10.3390/atmos12081014
复制
发表时间：
2021
期刊：
影响因子：
2.9
通讯作者：
K. Speer
中科院分区：
文献类型：
--
作者：
B. Quaife;K. Speer
开发了一个模型，以高度简化和理想化的形式探索由于对流汇和涡量源引起的火灾与大气的相互作用，以检查它们对蔓延和各种火锋几何形状稳定性的影响。该模型是在元胞自动机框架中构建的，是线性的，并表示背景流、对流汇以及每个燃烧单元处的火羽流引起的涡流。我们使用标准技术来求解所得的泊松方程，并仔细注意边界条件。开发了一种改进的 Bresenham 算法来表示对流。随着火灾几何形状的演变，三种基本流动类型（大规模背景流、汇流和涡流）以复杂的方式相互作用。火灾产生的涡-汇相互作用会产生一系列火灾行为，包括不稳定的蔓延速度、横向蔓延和动态指状现象。在这个简化的框架中，脉动与不断变化的火线宽度、交界火中的火锋加速以及较长的初始火线分解为多个头火有关。燃料非常简单地由单个燃烧时间参数表示。模型燃料是均匀的，但由于扩散和对流效应的动态相互作用而出现斑块。火灾引发的风和火锋几何形状的相互作用也取决于燃料燃烧时间。
A model is developed to explore fire–atmosphere interactions due to the convective sink and vorticity sources in a highly simplified and idealized form, in order to examine their effect on spread and the stability of various fire front geometries. The model is constructed in a cellular automata framework, is linear, and represents a background flow, convective sink, and vortices induced by the fire plume at every burning cell. We use standard techniques to solve the resulting Poisson equations with careful attention to the boundary conditions. A modified Bresenham algorithm is developed to represent convection. The three basic flow types—large-scale background flow, sink flow, and vortex circulation—interact in a complex fashion as the geometry of the fire evolves. Fire-generated vortex–sink interactions produce a range of fire behavior, including unsteady spread rate, lateral spreading, and dynamic fingering. In this simplified framework, pulsation is found associated with evolving fire-line width, a fire-front acceleration in junction fires, and the breakup of longer initial fire lines into multiple head fires. Fuel is very simply represented by a single burn time parameter. The model fuel is uniform yet patchiness occurs due to a dynamic interaction of diffusive and convective effects. The interplay of fire-induced wind and the geometry of the fire front depends also on the fuel burn time.
影响因子：
8
作者：
Clements, Craig B.;Lareau, Neil P.;Davis, Braniff
通讯作者：
Davis, Braniff