摘要
针对高热流密度燃烧室壁面热防护需求,提出了一种空气阵列射流冲击和燃油冷却肋板的集成冷却方式,在射流平均雷诺数Rej为1×10^(4)~3×10^(4),燃油进口流速vf为2.33~5.23m/s内,采用数值模拟方法对其传热特性进行了研究,并基于壁面加热侧当量对流换热系数的概念,分析了基准肋板以及燃油冷却肋板的传热增强作用。与无肋板靶面的阵列射流冲击相比,带肋板阵列射流冲击的面积平均当量对流换热系数是前者的1.6倍,压力损失系数相对提高了约25%;采用燃油冷却肋板,加热壁面综合传热能力进一步增强,在Rej=1×10^(4)时,采用燃油冷却肋板的面积平均当量对流换热系数是基准肋板的1.5倍以上,即使在Rej=3×10^(4)时,燃油冷却肋板的传热增强比也可以达到1.2;燃油冷却肋板的出口温度相对进口温度的提升在20~50K内,其提升幅度随着射流雷诺数或燃油进口流速的增大而减小。
An integrated cooling configuration was proposed by using array air-jets and fuel-cooled ribs to meet the thermal protection requirement in the high-heat-flux combustor wall.Numerical simulations were performed to characterize its heat transfer performance under a certain jet Reynolds number range(1×10^(4)≤Rej≤3×10^(4))and fuel inlet velocity range(2.33 m/s≤vf≤5.23 m/s).Based on the equivalent convective heat transfer coefficient on the heated side of target plate,the overall heat transfer enhancement by using baseline ribs and fuelcooled ribs is illustrated.With respect to the no-rib situation,the presence of ribs in array-jet impingement makes the area-averaged equivalent convective heat transfer coefficient 1.6 times of the former.At the same time,the pressure loss coefficient otherwise increased about 25%relatively.By using the fuel-cooled ribs,the overall heat transfer capacity is further promoted.When compared to the baseline-rib situation,the heat transfer enhancement ratio in the viewing of area-averaged convective heat transfer coefficient is up to 1.5 under Rej=1×10^(4).Even under Rej=3×10^(4),the heat transfer enhancement ratio for the fuel-cooled ribs is 1.2 at least.Totally,the temperature rise of the fuel at outlet with respect to the inlet temperature increased about 20~50 K.This temperature rise is reduced with the increase of jet Reynolds number and fuel inlet velocity.
作者
吴青
谭晓茗
田佳
张靖周
WU Qing;TAN Xiao-ming;TIAN Jia;ZHANG Jing-zhou(Key Laboratory of Thermal Management and Energy Utilization of Aircraft,College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《推进技术》
EI
CAS
CSCD
北大核心
2021年第4期941-949,共9页
Journal of Propulsion Technology
关键词
空气阵列射流
燃油冷却肋板
集成冷却结构
综合传热性能
数值模拟
Array air jets
Fuel-cooled ribs
Integrated cooling structure
Overall heat transfer performance
Numerical simulation
