Effect of anti-carbon deposition structure on fuel distribution of nozzle
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摘要:
针对航空发动机双油路喷嘴,采用试验和数值计算方法研究了不同防积碳结构对燃油分布的影响。采用光学分布式喷雾检测系统进行燃油分布测量试验,获取了不同防积碳喷嘴出口下游20 mm截面的锥角、周向分布和径向分布;并采用volume of fluid(VOF)仿真方法对不同防积碳结构的喷嘴进行了数值仿真研究。结果表明:相同供油压差下,喷嘴匹配防积碳结构后,喷雾锥角和燃油径向分布的峰值半径减小,小半径区域燃油分布占比升高。计算结果与试验结果符合较好,有效解释了防积碳气流对喷嘴燃油分布的影响。同一工况下,喷嘴匹配不同防积碳结构时,锥角的大小与喷口端面中心孔的气流速度相关,而周向分布主要与气液比相关。
Abstract:The effects of anti-carbon deposition structure on fuel distribution of aero-engine combustor double-way nozzle were investigated numerically and experimentally. Firstly, optical distributed spray detection system was applied to measure the fuel distribution, and the spray cone angel, circumferential and radial distribution of the section 20 mm downstream the nozzle outlet were obtained; the numerical simulation of the nozzle with different anti-carbon deposition structure was carried out by using VOF simulation method. The results showed that, under the same fuel pressure, the spray cone angel and peak radius of radial distribution decreased, while the proportion of fuel in the small radius increased, considering the effect of anti-carbon deposition structure of nozzle. The numerical calculation results were in good agreement with the experimental results, which can effectively explain the effect of anti-carbon flow on fuel distribution. Under the same fuel pressure and air pressure, when the nozzle was matched with different anti-carbon deposition structures, the spray cone angel was related to the velocity of the center airflow at the nozzle, and the circumferential distribution was mainly related to the gas-liquid ratio.
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表 1 防积碳结构设计参数
Table 1. Design parameters of anti-carbon deposition structure
参数 Model A Model B Model C Model D $ {n}_{\mathrm{a}1} $ 6 12 12 12 $ {D}_{\mathrm{a}\mathrm{o}1}/d $ 5.0 5.0 4.3 5.0 $ {n}_{\mathrm{a}\mathrm{o}2} $ 12 12 $ {D}_{\mathrm{a}\mathrm{o}2}/d $ 1.0 0.6 表 2 研究工况
Table 2. Working condition of rasearch
参数 对比工况 设计工况 ${\Delta p}_{ {\rm{f} } }$/MPa 2.2 2.2 ${\Delta p}_{ {\rm{a} } }$/kPa 0 12 表 3 设计工况下不同防积碳结构的气液比
Table 3. AFR of different anti-carbon deposition structure under design condition
模型 气液比 Model A 0.07 Model B 0.10 Model C 0.14 Model D 0.13 -
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