Numerical simulation of influence of surface reaction on combustion characteristics in propane-air premixed flame
Numerical simulation of influence of surface reaction on combustion characteristics in propane-air premixed flame
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DOI：
10.1299/transjsme.15-00044
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
S. Takatori;N. Hayashi;H. Yamashita
中科院分区：
文献类型：
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作者：
S. Takatori;N. Hayashi;H. Yamashita
火焰-壁面相互作用是燃烧室中的一个重要现象。特别是在小尺度燃烧室中，由于壁面比大，壁面对火焰特性的影响比常规尺度燃烧室大。采用数值模拟的方法研究了表面反应和热损失对丙烷-空气混合物自由基分布和放热速率的影响。建立了两平行平板间的二维狭缝燃烧器模型。改变平板间的距离，得到了被认为是表面反应导致自由基淬灭的活性壁和惰性壁条件下的分布。结果表明，活性壁面条件下的放热速率小于惰性壁面条件下的放热速率，而反应物消耗速率与惰性壁面条件下的相同。这是因为在气相反应中，壁面附近分布较广的OH等自由基在进入气相反应之前就被表面反应淬灭了。因此，在高壁温条件下，主动壁面的吹风距离大于惰性壁面的吹风距离。在低壁温条件下，由于表面反应的影响与热损失的影响相比可以忽略不计，因此对于活性壁和惰性壁条件，该距离是相同的值。
Flame-wall interaction is an important phenomenon on combustors. Especially, the influence of wall on the flame characteristics in small scale combustors becomes larger than that on normal scale ones because of their large surface-to-volume ratio. In this study, the influence of surface reaction and heat-loss on radical distributions and heat release rate of propane-air mixture is investigated using numerical simulation. A two-dimensional slit burner between two parallel plates is modeled. The distance between the plates is changed, and the profiles are obtained for both active wall, which is considered surface reaction causes radical quenching, and inert wall conditions. As a result, it is found that heat release rate for active wall condition is smaller than that for inert wall condition while the reactant consumption rate is the same for active and inert wall conditions. It is because that the radical which distribute widely near the wall like OH is quenched by surface reaction before be used in gas phase reaction. Thus, the blow off distance for active wall with high wall temperature condition is larger than that for inert wall condition. For low wall temperature condition, since the influence of surface reaction is negligibly small as compared with that of heat-loss, the distance is the same value for active and inert wall conditions.