CAJ | 학술논문

通过数值模拟研究了固体材料（石英、不锈钢和SiC）对微型钝体燃烧器内氢气/空气预混火焰的吹熄极限的影响。结果表明：计量比为0.5时，3个燃烧器对应的吹熄极限分别为36、25和21 m·s-1。理论分析揭示了微型钝体燃烧器中火焰稳定性与流动和传热之间的相互作用非常密切。当热导率较小时，通过壁面向上游传导的热量较少，壁面对未燃预混气的预热效果较差，燃烧后的气体膨胀相对较弱，从而钝体后的低速区面积较大，稳燃效果较好。对于不锈钢和SiC燃烧器，由于SiC的发射率更大，通过壁面的散热损失较大，从而使得其吹熄极限较小。为获得良好稳燃性能的微型钝体燃烧器选择合适的材料提供了指导。
통과수치모의연구료고체재료（석영、불수강화SiC）대미형둔체연소기내경기/공기예혼화염적취식겁한적영향。결과표명：계량비위0.5시，3개연소기대응적취식겁한분별위36、25화21 m·s-1。이론분석게시료미형둔체연소기중화염은정성여류동화전열지간적상호작용비상밀절。당열도솔교소시，통과벽면향상유전도적열량교소，벽면대미연예혼기적예열효과교차，연소후적기체팽창상대교약，종이둔체후적저속구면적교대，은연효과교호。대우불수강화SiC연소기，유우SiC적발사솔경대，통과벽면적산열손실교대，종이사득기취식겁한교소。위획득량호은연성능적미형둔체연소기선택합괄적재료제공료지도。
In the present paper, the effect of solid material on the blow-off limit of a micro-combustor was numerically investigated. For the three solid materials selected, i.e., quartz, stainless steel, and SiC, the corresponding blow-off limits obtained for the three combustors are 36, 25 and 21 m·s-1. The underlying mechanisms are analyzed in terms of the interactions between heat transfer, flow field and flame stabilization. It is revealed that for small thermal conductivity (i.e., quartz), less heat is conducted to upstream walls, the fresh mixture is not sufficiently preheated, and the gas volume does not expand so significantly, leading to a larger“low velocity zone” and thus a higher blow-off limit. For the other two materials with higher thermal conductivities (i.e., stainless steel and SiC), higher thermal emissivity (i.e., SiC) results in higher “total heat loss ratio” and lower blow-off limit. It can be concluded that the solid material with a relatively low thermal conductivity and emissivity is beneficial to obtain higher blow-off limit for the micro bluff body combustor.