双层混合管排气出口导流遮挡的冷却与红外辐射特性  

Cooling and infrared radiation characteristics of diversion shielding atexhaust outlet of double-layer mixing duct

作　　者：宋健[1] 张靖周[1] 单勇[1] SONG Jian;ZHANG Jingzhou;SHAN Yong(Key Laboratory of Thermal Management and Energy Utilization of Aircraft,Ministry of Industry and Information Technology,College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学能源与动力学院航空飞行器热管理与能量利用工业和信息化部重点实验室,南京210016

出　　处：《航空动力学报》2024年第5期95-106,共12页Journal of Aerospace Power

基　　金：国家科技重大专项(J2019-Ⅲ-0009-0053)。

摘　　要：以降低一体化红外抑制器混合管出口导流片温度及其红外辐射强度为目的,设计了双层混合管和带冷却结构的导流器。通过CFD和红外辐射强度空间分布数值仿真,研究了双层混合管强迫冷却进气流量、导流器出口形状和波瓣瓣数对排气喷流和排气混合管红外辐射强度的影响。计算结果表明,双层混合管+导流器结构相较于基准模型(单层混合管,导流片无冷却)可以有效降低导流器可视表面高温区,导流器自身的红外辐射强度降幅可达82.9%;导流器出口的波瓣可以诱导流向涡对,强化冷却气流与混合管出口排气尾流掺混,排气红外辐射强度相对于基准模型最大的降幅可达68.2%,混合管及其排气的总体辐射强度的降幅峰值可达86.4%。排气红外辐射强度以及总体辐射强度均随着波瓣瓣数的减少而逐渐减小,导流器出口过多的波瓣瓣数设计反而不利于流向涡的发展。混合管总体辐射强度随着强迫冷却气流流量的增加而逐渐减小,冷却气流流量与主流流量比值为0.1时,相对于不通冷却气流的情况,总体辐射强度的降幅峰值为68.3%。In order to reduce the temperature and infrared radiation intensity of the diverter at the outlet of the mixing duct of the integrated infrared suppressor,a double mixing duct and a diverter with cooling structure were designed.Through CFD and numerical simulation of the spatial distribution of infrared radiation intensity,the effects of inlet flow rate of forced cooling,outlet shape of deflector and number of valves on the infrared radiation intensity of exhaust jet and exhaust mixing duct were studied.The calculation results showed that compared with the reference model(single-layer mixing duct,no cooling of the deflector),the structure of double-layer mixing duct and deflector can effectively reduce the visible surface high-temperature region of the deflector,and the infrared radiation intensity of the deflector itself can be reduced by 82.9%. The wave disc at the outlet of the deflector can induce streamwise vortexpairs,and the enhanced cooling air can be mixed with the exhaust wake at the outlet of the mixing duct.Compared with the benchmark model,the infrared radiation intensity of the exhaust can drop up to 68.2%,and the overall radiation intensity of the mixing duct and its exhaust can drop up to 86.4%. The exhaustinfrared radiation intensity and the overall radiation intensity decreased gradually with the decrease of thenumber of valves and the excessive number of valves at the outlet of the diverter was not conducive to thedevelopment of streamwise vortex. The overall radiation intensity of the mixed duct gradually decreasedwith the increase of the forced cooling airflow flow rate. When the ratio of the cooling airflow flow rate tothe main flow rate was 0.1,the overall radiation intensity decreased by a peak of 68.3% compared with thesituation without cooling airflow.

关 键 词：红外抑制器 弯曲混合管 强迫冷却 辐射遮挡 强化混合 红外辐射特性 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程] V211.3