基于化学反应动力学机理的中等尺寸甲烷湍流扩散火焰的数值模拟

发布时间：2018-06-10 06:20

本文选题：甲烷火焰 + 简化机理　；参考：《火灾科学》2015年02期

【摘要】：通过代码修改,在大涡模拟(LES)中嵌入气相化学反应速率、组分热力学性质和输运特性三大机理文件,严格意义上实现甲烷燃烧的四步简化机理与火灾动力学模拟软件(FDS)的成功对接。燃烧模型采用针对多组分燃料的涡耗散概念(EDC)模型,模拟0.3m直径的甲烷湍流扩散火焰,并分别与基于无限快反应速率的总包单步和两步化学反应预测结果对比。分析预测结果可知:四步机理能够很好的适应FDS框架,其模拟结果具有可靠性,时均温度、速度和主要反应物的预测结果高度一致;机理导入后可以预测CO2、H2O以及中间产物CO和H2的浓度,更合理地描述了火灾中气相产物的产生与输运过程。不同反应机制下主产物CO2和H2O浓度对比结果理想,在高温反应区内存在一定的差异,在高温反应区外呈现出高度的一致性。
[Abstract]:By code modification, the gas phase chemical reaction rate, the thermodynamic properties of components and the transport characteristics are embedded in the large eddy simulation (les). In strict sense, the four-step simplified mechanism of methane combustion is successfully docked with the fire dynamics simulation software (FDS). The combustion model is designed to simulate the turbulent diffusion flame of methane with a diameter of 0.3 m and is compared with the prediction results of one-step and two-step chemical reactions based on the infinite fast reaction rate. The results of analysis and prediction show that the four-step mechanism can adapt well to the FDS framework, and the simulation results are reliable, time-averaged temperature, velocity and the predicted results of the main reactants are highly consistent; The concentration of CO _ 2H _ 2O and the intermediate products CO and H _ 2 can be predicted after the introduction of the mechanism, and the generation and transport process of gaseous products in fire can be described more reasonably. The concentration of CO _ 2 and H _ 2O in different reaction mechanisms is ideal, and there are some differences in the reaction region at high temperature, and there is a high degree of consistency outside the reaction zone at high temperature.
【作者单位】：中国科学技术大学火灾科学国家重点实验室;
【基金】：国家自然科学基金(51176181) 国家重点基础研究发展计划(973计划,2012CB719704) 高等学校博士学科点专项科研基金(20123402110047,20133402110010)资助
【分类号】：X932

【共引文献】