摘要
以某型涡扇发动机为原型,建立了1/10缩比的分开排气式涡扇发动机排气喷管物理模型,采用大涡模拟(LES)计算了不同外涵偏轴距离的排气喷管非稳态流场,利用FW-H(Ffows Williams-Hawkings)声学模型和傅里叶变换得到了排气喷流噪声声压级空间分布特征.计算结果表明:外涵偏轴式分开排气喷管有抑制排气喷流噪声的作用.喷流噪声整体抑制效果与偏轴距离有关,在偏轴距离为0.15 D时,排气喷管下方的噪声降低达到最大,且排气噪声峰值由原型的146.7dB降低到139.5dB,降低了7.2dB.研究的排气结构和数值计算方法可作为分开排气式涡扇发动机降噪设计的参考.
Based on large eddy simulation and FW-H（Ffows Williams-Hawkings） acoustics simulation,the unsteady flow field and the jet noise distribution of overall sound pressure level（OASPL） were obtained for one 1/10 scaled turbofan engine with separated exhaust system at various bypass offset distances.It shows that the structure of bypass offset has the ability of depressing the exhaust jet noise.The noise depression effects have relation with the bypass offset distance.Exhaust jet noise is reduced from 146.7 dB to139.5 dB at the offset distance of 0.15D which is the maximal noise reduction.The configuration and the numerical method mentioned can be taken into consideration in the design of the separated exhaust for turbo-fan engine.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2012年第5期1139-1145,共7页
Journal of Aerospace Power
