Korobeinichev Oleg, Karpov Alexander, Shaklein Artem, Paletsky Alexander, Chernov Anatoliy, Trubachev Stanislav, Glaznev Roman, Shmakov Andrey, Barbot'ko Sergey
Voevodsky Institute of Chemical Kinetics and Combustion SB RAS, 630090 Novosibirsk, Russia.
Udmurt Federal Research Center, 426067 Izhevsk, Russia.
Polymers (Basel). 2022 Feb 24;14(5):911. doi: 10.3390/polym14050911.
For the first time, a comprehensive study of downward flame spread over glass-fiber-reinforced epoxy resin (GFRER) slabs in oxidizer flow has been carried out experimentally and numerically. Microthermocouples were used to measure the temperature profiles on the solid fuel's surface and in the flame, and a video camera was used to measure the rate of flame spread (ROS). The ROS was found to be linearly dependent on the oxygen concentration, to be inversely proportional to the slab thickness and not to depend on the direction of the flame spread over the slab. The absence of the influence of the forced oxidizing flow velocity and the weak influence of the GFRER pyrolysis kinetics on the ROS were observed. For the first time, a numerical model of flame spread over reinforced material with thermal conductivity anisotropy was developed on the basis of a coupled 'gas-solid' heat and mass transfer model, using modifications of the OpenFOAM open-source code. The sensitivity analysis of the model showed that the thermal conductivity in the normal direction to the GFRER surface had a much greater effect on the ROS than the thermal conductivity along the direction of flame propagation. The numerical results show good agreement with the experimental data on the dependences of the ROS on oxygen concentration, slab thickness and the N/O mixture flow velocity, as well as temperature distributions on the fuel surface, the maximum flame temperatures and the flame zone length.
首次对氧化剂流中玻璃纤维增强环氧树脂（GFRER）平板上的向下火焰蔓延进行了全面的实验和数值研究。使用微型热电偶测量固体燃料表面和火焰中的温度分布，并使用摄像机测量火焰蔓延速率（ROS）。发现ROS与氧气浓度呈线性相关，与平板厚度成反比，且不依赖于火焰在平板上的蔓延方向。观察到强制氧化气流速度对ROS没有影响，GFRER热解动力学对ROS的影响较弱。首次基于耦合的“气-固”传热传质模型，使用开源代码OpenFOAM的修改版本，开发了具有热导率各向异性的增强材料上火焰蔓延的数值模型。模型的敏感性分析表明，与火焰传播方向上的热导率相比，GFRER表面法向的热导率对ROS的影响要大得多。数值结果与ROS对氧气浓度、平板厚度和N/O混合气流速度的依赖性以及燃料表面温度分布、最大火焰温度和火焰区长度的实验数据吻合良好。
