分排式三股流喷管流动与噪声特性数值研究  

Numerical study on the flow and sound characteristics of split three-stream nozzle

作　　者：杨玉明 周莉 史经纬[1] 王占学[1] YANG Yuming;ZHOU Li;SHI Jingwei;WANG Zhanxue(School of Power and Energy,Northwestern Polytechnical University,Xi’an 710072,China;Collaborative Innovation Center for Advanced Aero-Engine,Beijing 100191,China)

机构地区：[1]西北工业大学动力与能源学院,西安710072 [2]先进航空发动机协同创新中心,北京100191

出　　处：《航空动力学报》2024年第12期53-65,共13页Journal of Aerospace Power

基　　金：国家自然科学基金(52076180);陕西省杰出青年科学基金(2021JC-10);国家科技重大专项(J2019-Ⅱ-0015-0036);航空发动机及燃气轮机基础科学中心项目(P2022-B-Ⅰ-002-001,P2022-B-Ⅱ-010-001);中央高校基本科研业务费专项资金。

摘　　要：采用数值模拟方法研究了引入第三股流后喷管的流动与噪声机理,第三股流涵道比增大对流动与噪声特性的影响。结果表明:引入第三股流使得风扇流速度核心区长度增加,主流核心区末端与自由来流的直接掺混轴向距离缩短,两者间的湍流掺混峰值下降约2.63%,但由于喷流下游剪切层厚度增加,有限的低速第三股流在各方向上的降噪效果有限。第三股流涵道比的增大方便实现,这不仅可以在降低耗油率的同时增加发动机推力,还可以降低排气系统的宽频噪声。第三股流涵道比增大至2.52,不仅使得主流核心区末端的湍流掺混强度减弱,而且使得第三股流与自由来流间强剪切层的掺混强度减弱,主流核心区末端的掺混强度相较于设计工况降低8.57%,各方向上的总声压级均降低,降低峰值约2.37 dB。The influences of the three-stream introduction and the tertiary bypass ratio on the flow and noise characteristics of the three-stream nozzle were studied by the numerical simulation method.The results showed that the three-stream introduction increased the length of the bypass potential core,shortened the axial distance of the direct mixing between the end of the primary potential core and the free stream,and reduced the peak value of the turbulent mixing between them by about 2.63%.However,due to the increase of the shear layer thickness,the low-speed three-stream had limited noise reduction effect in all directions.The increase of the tertiary bypass ratio was easy to achieve,at the cost of reducing fuel consumption,and it can increase the engine thrust and reduce the broadband noise of the exhaust system.The increase of tertiary bypass ratio to 2.52 weakened not only the turbulent mixing intensity at the end of the primary potential core,but also the mixing intensity of the strong shear layer between the three-stream and the free stream.Compared with the design condition,the mixing intensity at the end of the primary potential core decreased by 8.57%,and the overall sound pressure level decreased in all directions,with a peak value of about 2.37 dB.

关 键 词：三股流喷管 涵道比 机理分析 流动特性 噪声特性 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]