来流边界层厚度对开式空腔气动声学特性的影响分析  

Analysis of aeroacoustic characteristics in open cavities influenced by boundary-layer thickness

作　　者：杨党国[1] 罗新福[1] 李建强[1] 蒋卫民[1] 

机构地区：[1]中国空气动力研究与发展中心空气动力学国家重点实验室,四川绵阳621000

出　　处：《空气动力学学报》2011年第4期486-490,共5页Acta Aerodynamica Sinica

基　　金：重点基金项目(6140516);国家"863"计划课题(2007AA04Z129)

摘　　要：分析了不同来流边界层厚度与空腔深度比(δ/D)对长深比(L/D)为8的开式空腔内不同测点的声压级分布和声压频谱特性的影响。试验马赫数是0.6和1.5,相应的Re为1.23×107和2.26×107(基于每米)。结果表明,δ/D减小,导致开式空腔内不同测点声压级均有不同程度的增大;导致空腔上方剪切层与腔内流动或腔后壁相互作用能量增加,引起腔内同一测点不同离散频率对应的声压级增大。可见,δ/D减小,腔内流动自激振荡更易引起空腔自身结构和腔内储藏物结构振动和疲劳破坏。This paper presents effects of different boundary-layer thickness to cavity depth ratios on sound pressure level（SPL） distributions and sound pressure frequency spectrum characteristics（SPFS） inside the open cavity with length to depth ratio of 8.The data presented herein was obtained over Mach numbers of 0.6 and 1.5 at a Reynolds numbers of 1.23×107 and 2.26×107 per meter.The results show that decrease in ratios of the boundary-layer thickness to the cavity depth（δ/D） leads to increase in SPL on the different position measurement inside the open cavity.It also causes intense interaction of the shear-layer over the cavity and flow in the cavity or cavity rear-wall,which leads to increase in SPL at different discretized frequencies for measurement positions in the cavity.Generally,decrease in δ/D leads to flow self-oscillations and aerodynamic noise which have adverse influences on cavities and internal weapon＇s structural vibration.

关 键 词：开式空腔 边界层厚度 声学特性 声压级 声压频谱 

分 类 号：V211.7[航空宇航科学与技术—航空宇航推进理论与工程]