Ventilation and cooling test of the core nacelle for civil turbofan engine with large bypass ratio
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摘要:
设计了全尺寸大涵道比涡扇发动机核心机舱通风换热试验系统,通过改变冷却气流流量、核心机机匣表面发热量以及核心机舱外壳保温层来研究舱内对流换热特性。试验结果表明:引气流量增加,各段核心机机匣的表面传热系数均随之增大;因前/后舱间存在高阶法兰,前舱引气量增加对后舱机匣表面对流换热几乎没影响;引气流量达到单孔进气0.05 kg/s后,舱内空间温度的改善有限;空间上,前舱上部气流温度比下部高出10 K左右,后舱高出20 K左右;相同引气流量下,机匣表面发热量提高,各段机匣的表面传热系数略提高,差值约10 W/(m2·K);保温层的存在导致核心机机匣通过辐射换热的方式向环境传递的热量减小,此时传热的方式主要依靠对流换热,因此表面传热系数相对提高,差值最大约60 W/(m2·K)。采用最小二乘法获得各段核心机机匣表面传热经验公式,可为大涵道比涡扇发动机核心机舱通风冷却工程设计提供参考。
Abstract:A full-scale large bypass ratio turbofan engine core nacelle ventilation and heat transfer test system was designed by changing the cooling air flow rate, the heat generation on the core casing surface and the core nacelle shell insulation to study the convective heat transfer characteristics in the cabin. The results showed that with the increase of intake air flow rate, the surface heat transfer coefficient of the core casing of each section increased accordingly. Due to the presence of high-level flanges in the front/rear compartments, the increase in the front compartment intake air flow rate had almost no influence on the convective heat transfer on the surface of the rear compartment casing. When the intake air flow rate reached 0.05 kg/s, the improvement of the cabin space temperature was limited. Spatially, the air flow temperature of the upper part of the front cabin was about 10 K higher than that of the lower part, and the rear cabin was about 20 K higher. At the same intake air flow rate, the heat output of the casing surface increased, and the surface heat transfer coefficient of the casing increased slightly, with a difference of about 10 W/(m2·K). The existence of the insulation layer caused the heat transfer of the core casing to the environment through radiation heat exchange to decrease, and the heat transfer method mainly relied on convection heat transfer, so the surface heat transfer coefficient was relatively improved, with the difference about 60 W/(m2·K). The empirical formulae of surface heat transfer for each section of the core casing were obtained by using the least squares method, which can be used as a reference for the design of ventilation and cooling engineering for the core nacelle with large bypass ratio turbofan.
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表 1 试验工况
Table 1. Test conditions
试验
工况有无
保温层进气口
布局$\dot{ m }$/(kg/s) 机匣
发热量环境
温度/K环境
压力/Pa1 有 布局1 0.2~1.2 高 303.7 100190 2 有 布局1 0.2~1.2 低 300.2 100880 3 有 布局2 0.1~0.6 高 300.1 100900 4 无 布局1 0.2~1.2 高 299.3 100370 表 2 机匣加热温升
Table 2. Casing heating temperature rise
部件名称 温升/K 高发热量 低发热量 压气机增压级 70 20 压气机中间级 100 50 压气机中间级 100 50 压气机高压级 120 70 燃烧室 140 90 高压涡轮 100 50 低压涡轮 130 80 低压涡轮 130 80 排气段 150 100 表 3 对流换热经验关联式
Table 3. Empirical correlation of convective heat transfer
机匣分段
编号Nu 工况1 工况2 1 0.002Re0.935 0.066Re0.451 2 0.012Re0.674 0.21Re0.433 3 0.017Re0.652 0.022Re0.576 4 0.02Re0.687 0.028Re0.632 5 0.032Re0.633 0.052Re0.578 6 0.013Re0.712 0.346Re0.438 7 0.018Re0.71 0.078Re0.562 8 0.12Re0.617 0.175Re0.519 9 0.013Re0.771 0.024Re0.671 表 4 对流换热经验关联式(工况4)
Table 4. Empirical correlation of convective heat transfer (condition 4)
机匣分段编号 Nu 1 0.048Re0.578 2 0.079Re0.498 3 0.466Re0.384 4 0.044Re0.619 5 0.042Re0.619 6 0.02Re0.654 7 0.011Re0.754 8 0.019Re0.733 9 0.009Re0.77 -
[1] SEGAL C. Aircraft engine bay cooling and ventilation: design and modeling[J]. Journal of Aircraft,1997,34(1): 141-144. doi: 10.2514/2.2150 [2] SAWYERS A, NIGEL D. Core compartment ventilation devices for nacelles of gas turbine engines for cooling a core compartment of a gas turbine engine: EP20160205550[P]. 2019-08-07. [3] KOZACZUK K. Engine nacelles design: problems and challenges[J]. Proceedings of the Institution of Mechanical Engineers: Part G Journal of Aerospace Engineering,2017,231(12): 2259-2265. doi: 10.1177/0954410017706993 [4] SUCIU G L , CHANDLER J M , PAPA F . Gas turbine engine nacelle ventilation manifold for cooling acces-sories: US10526910B2[P]. 2020-01-07 [5] 缪国君. 民用飞机短舱内通风冷却系统设计和验证研究[J]. 工程与试验,2015,55(3): 92-94. doi: 10.3969/j.issn.1674-3407.2015.03.025MIAO Guojun. Design and verification of the ventilation and cooling system in the nacelle of a civil aircraft[J]. Engineering and Testing,2015,55(3): 92-94. (in Chinese) doi: 10.3969/j.issn.1674-3407.2015.03.025 [6] 王玉梅,吕美茜. 发动机通风冷却系统的影响因素分析[J]. 工程与实验,2011,51(2): 16-18.WANG Yumei,LÜ Meiqian. Influencing factors analysis on engine cooling system[J]. Engineering and Testing,2011,51(2): 16-18. (in Chinese) [7] 王涛,李飞行. 航空发动机短舱通风冷却系统设计方案分析及对比[J]. 现代机械,2013,1(13): 40-42.WANG Tao,LI Feixing. Analysis and comparison of design schemes of aero-engine nacelle ventilation and cooling system[J]. Modern Machinery,2013,1(13): 40-42. (in Chinese) [8] BOILEAU M,DUCHAINE F,SOMMERER Y,et al. Large eddy simulation of heat transfer around a square cylinder using unstructured grids[J]. AIAA Journal,2013,51(2): 372-385. doi: 10.2514/1.J051800 [9] PENG H,MOHAMMADINIA S. Modeling and simula tion of ventilation and cooling of aircraft piston engine based on genetic algorithm[J]. Engineering Applications of Computational Fluid Mechanics,2020,4(1): 980-988. [10] 张亚海,李小宁,谢永奇,等. 动力舱通风冷却性能仿真及其影响因素分析[J]. 科技创新导报,2010(33): 106. doi: 10.3969/j.issn.1674-098X.2010.33.084ZHANG Yahai,LI Xiaoning,XIE Yongqi,et al. Simulation of ventilation and cooling performance of power cabin and analysis of its influencing factors[J]. Science and Technology Innovation Guide,2010(33): 106. (in Chinese) doi: 10.3969/j.issn.1674-098X.2010.33.084 [11] VEDESHKIN G, DUBOVITSKIY A, VERSEUX O, et al. Experimental investigations of hydraulic devices performance in aviation engine compartment[R]. [S.l.]: 28 International Congress of the Aeronautical Sciences. Brisbane, Australia: RAS-Australia Division, 2012: 1-8. [12] URIZ J F, REMY B, VERSEUX O, et al. Improved temperature extrapolation methods for powerplant systems[R]. AIAA-2010-4328, 2010. [13] URIZ J F,REMY B,VERSEUX O,et al. Model identification for temperature extrapolation in aircraft powerplant systems[J]. International Journal of Thermal Sciences,2013,64(Complete): 162-177. [14] 王玉梅,李海. 航空发动机舱温超限故障分析[J]. 工程与试验,2017,57(2): 52-55. doi: 10.3969/j.issn.1674-3407.2017.02.015WANG Yumei,LI Hai. Fault analysis of aero engine cabin temperature exceeding limit[J]. Engineering and Testing,2017,57(2): 52-55. (in Chinese) doi: 10.3969/j.issn.1674-3407.2017.02.015 [15] 马明明. 航空发动机短舱流动与换热的计算研究[D]. 西安: 西北工业大学, 2007.MA Mingming. Computational research on the flow and heat transfer of aero-engine nacelles[D]. Xi’an: Northwestern Polytechnical University, 2007. (in Chinese) [16] 王杏涛,张靖周,单勇. 发动机舱通风冷却和遮挡隔热综合降温效果[J]. 南京航空航天大学学报,2013,45(5): 652-657. doi: 10.3969/j.issn.1005-2615.2013.05.013WANG Xingtao,ZHANG Jingzhou,SHAN Yong,et al. Comprehensive cooling effect of engine compartment ventilation cooling and shielding heat insula tion[J]. Journal of Nanjing University of Aeronautics and Astronautics,2013,45(5): 652-657. (in Chinese) doi: 10.3969/j.issn.1005-2615.2013.05.013 [17] 马文昌,王维,马松,等. 某型飞机发动机舱通风冷却仿真研究[J]. 飞机设计,2013,33(3): 27-30,42.MA Wenchang,WANG Wei,MA Song,et al. Simulation study on ventilation and cooling of a certain aircraft engine compartment[J]. Aircraft Design,2013,33(3): 27-30,42. (in Chinese) [18] 谢永奇,余建祖,高红霞,等. 直升机动力舱通风冷却系统仿真[J]. 航空动力学报,2006,13(2): 297-302. doi: 10.3969/j.issn.1000-8055.2006.02.012XIE Yongqi,YU Jianzu,GAO Hongxia,et al. Simulation of the ventilation and cooling system of the helicopter power compartment[J]. Journal of Aeronautical Dynamics,2006,13(2): 297-302. (in Chinese) doi: 10.3969/j.issn.1000-8055.2006.02.012