摘要
针对涡扇发动机用三轴承矢量喷管(3BSN),通过数值模拟的方法研究了在巡航和垂直起降(VTOL)状态即非矢量和90°矢量状态下三轴承矢量喷管的红外辐射空间分布特征,并分析了其影响机理。结果表明,在非矢量状态下由于特殊的几何型面使得喷管下壁面出现了局部高温区,喷流形状也变成椭圆锥形,造成垂直探测面上正探测角壁面红外辐射较负探测角最大增加44.6%,水平探测面上的燃气红外辐射大于垂直探测面;90°矢量状态下,由于偏转的喷管结构对前端高温部件的遮挡,总辐射峰值仅为非矢量状态的43.3%;喷管90°矢量偏转使得远离曲率中心一侧的气流速度降低温度升高,喷管外侧出现了大范围的局部高温区,导致垂直探测面负探测角范围的壁面辐射大于正探测角范围,最大相对差值达到71.9%。喷管偏转也遮挡了部分喷管内部的高温燃气,垂直探测面负探测角的仅能覆盖喷管出口处的高温燃气区域,明显小于正探测角,造成燃气辐射出现了20%的最大相对差值。
In view of the three bearing swivel nozzle(3BSN)for turbofan engines,numerical simulation method was used to study the spatial distribution of infrared radiation signature of three bearing swivel nozzle under the working conditions of vertical take-off and landing(VTOL)and cruise(non-vectorial and 90° vectorial conditions), and the influence mechanism was also analyzed. The results showed that under non-vector state, the local high temperature area appeared on the lower wall of 3BSN due to the special geometry surface,and the jet shape became an elliptical cone,resulting in a maximum increase of 44. 6% in wall infrared radiation from positive detection angle over negative detection angle at vertical plane,and the gas radiation on horizontal detection plane was greater than that on vertical detection plane. Under 90° vector state,the total radiation peak was only 43. 3% of the non-vector state due to the shielding effect of deflected 3BSN structure on the front high-temperature components. The vector deflection of 3BSN reduced the gas velocity on the side far from curvature center and increased the temperature. A large local high temperature area appeared on the outside of the nozzle,which caused the wall radiation in negative detection angle range larger than that in positive detection angle on vertical detection plane, and the maximum relative difference was up to 71. 9%. The deflection also obstructed the high temperature gas inside the nozzle. The negative detection angle of vertical detection plane can only cover the high temperature gas area at the nozzle exit,which was significantly smaller than the positive detection angle,resulting in the maximum relative difference of 20% in gas radiation.
作者
是介
周莉
史经纬
王占学
SHI Jie;ZHOU Li;SHI Jingwei;WANG Zhanxue(School of Power and Energy,Northwestern Polytechnical University,Xi'an 710072,China)
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2022年第6期1195-1205,共11页
Journal of Aerospace Power
基金
国家科技重大专项(J2019⁃Ⅱ⁃0015⁃0036)
国家自然科学基金(51876176,51906204,52076180)
陕西省杰出青年基金(2021JC⁃10)。
关键词
涡扇发动机
三轴承矢量喷管
垂直起降
温度分布
红外辐射特性
turbofan engine
three bearing swivel nozzle
vertical take-off and landing
temperature distribution
infrared radiation signature
