折叠V形火焰稳定器原型的冷态与稳燃特性研究

Cold Flow and Combustion Characteristics of a Prototype Folded-V Flame Holder

关键词:  加力燃烧室  火焰稳定器  折叠V形钝体  冷态性能  稳燃特性

Key words:  After burner  Flame holder  Folded-V bluff body  Cold characteristic  Flame stability

摘要:

为了获得折叠V形钝体这一新型火焰稳定器原型的冷、热态特性，采用风洞实验与混合雷诺平均/大涡模拟结合的方法，对10组不同折叠角的折叠V形钝体火焰稳定器模型进行了冷态实验与热态数值模拟研究。其中，冷态实验风速为10~50m/s，来流雷诺数为1×10⁴～8×10⁴，热态数值模拟工况的进气温度为700K、来流速度为50~150m/s，来流雷诺数为2×10⁴～6×10⁴，当量比为0.2~1。通过实验测得了不同折叠角折叠V形钝体总压恢复系数，通过数值模拟进一步获得了阻力系数、吹熄性能与燃烧效率，并获得了折叠V形钝体下游火焰时均轮廓。研究表明，折叠V形钝体总压恢复系数与阻力系数优于标准钝体，总压恢复系数随钝体折叠角减小而增大，阻力系数随折叠角减小而减小；折叠V形钝体抗吹熄能力与燃烧效率均优于标准V形钝体；折叠V形钝体的下游火焰扩散特性与标准V形钝体有显著差异。

Abstract:

In order to obtain the cold flow and combustion characteristics of a new proto type flame holder called folded V bluff body， the cold flow experiments and combustion numerical simulation of 10 groups of folded V bluff body flame holders with different folding angles were carried out by wind tunnel experiments and Hybrid RANS/LES simulation. The cold flow experimental wind speed is 10~50m/s with Re number range of 1×10⁴ to 8×10⁴. And the combustion numerical simulation conditions are： intake temperature 700K， inflow speed 50~150m/s， Re number range from 2×10⁴ to 6×10⁴， equivalent ratio 0.2~1. The total pressure recovery coefficient of folded V bluff bodies with variable folding angles was measured by experiments. The drag coefficient， blowing out performance and combustion efficiency of folded-V bluff body were further obtained by numerical simulation， and the flame shape downstream were analyzed in detail. The results show that the total pressure recovery coefficient and drag coefficient of each folded V bluff bodies are better than those of the standard V bluff body. The total pressure recovery coefficient increases with the decrease of the folding angle， while the drag coefficient decreases. The blow out performance and combustion efficiency of the folded V bluff body are better than those of the standard V bluff body. The downstream flame diffusion characteristics of the folded V- bluff body are significantly different from those of the standard V bluff body.