The fuel inclination and wind velocity play a significant role on the forward flame spread behavior. It deserves further study since the heat transfer mechanism and flame spread characteristics coupled these two factors are not clear yet. In this paper, a thermally thin slab of PMMA that could be inclined from a horizontal (0°) to a vertical (90°) angle is used to investigate flame spread behavior under the condition of the concurrent ambient airflow. A wind tunnel is utilized to provide a uniform concurrent airflow, ranging from 0 (quiescent) to 3 m/s with an interval of 0.5 m/s. Essential flame characteristic parameters are collected to quantify the flame spread process, including flame spread rate (FSR), burning rate, heat release rate as well as heat flux feedback both in the pyrolysis and preheating zones. A mechanism, including the competition between the acceleration of buoyancy brought by inclination and the cooling effect of ambient airflow for relatively high wind velocity, is developed. The relationship between flame length and pyrolysis length is investigated. Moreover, the evolution of both heat release rate per unit width and standoff distance as a function of pyrolysis length are analyzed. A dimensionless heat release rate for upward flame at different wind velocities is used to scale the dimensionless flame length with a power-law exponent of 0.77 and −1.92. In addition, the dimensionless heat flux in preheated zone decay with distance as a function of power law. A predictive formulation of FSR coupled with inclination angle and wind velocity is proposed. This study facilitates the understanding of the interaction of fuel inclination angle and horizontal ambient airflow from aspect of heat and mass transfer.

燃料的倾斜度和风速对正向火焰传播行为起着重要作用。由于传热机理和火焰蔓延特性结合这两个因素尚不明确，值得进一步研究。在本文中，可以使用可从水平（0°）倾斜到垂直（90°）角度的PMMA热薄板来研究在同时存在环境气流的情况下的火焰蔓延行为。风洞用于提供均匀的并发气流，范围从0（静态）到3 m / s（间隔为0.5 m / s）。收集基本的火焰特征参数以量化火焰扩散过程，包括热解区和预热区的火焰扩散率（FSR），燃烧率，放热率以及热通量反馈。一种机制 包括相对于较高风速的倾斜带来的浮力的加速与环境气流的冷却效果之间的竞争。研究了火焰长度与热解长度之间的关系。此外，分析了每单位宽度的放热率和支座距离随热解长度的变化。在不同风速下，向上火焰的无量纲放热率用于按幂律指数0.77和-1.92缩放无量纲火焰长度。另外，预热区中的无量纲热通量随距离随幂律的变化而衰减。提出了FSR与倾角和风速相结合的预测公式。