一种新的激波/滑移线共存结构  

A new shock wave/slip line structure for supersonic flow at the high angle of attack

作　　者：白晨媛[1] 孙元昊[1] 耿扬[1] 李韶光[1] 吴子牛[1] 

机构地区：[1]清华大学航天航空学院,北京100084

出　　处：《中国科学：物理学、力学、天文学》2013年第1期94-103,共10页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重大基础研究计划资助项目(批准号:973-2012CB720200)

摘　　要：超音速飞行器机动飞行时面临大攻角流动问题.这里,我们报道一种由大攻角飞行导致机翼上表面出现特殊的脱体激波、再压缩激波与滑移线共存的现象.在大攻角条件下,超音速气流在机翼前缘产生脱体激波,波后亚音速气流在机翼上表面加速到超音速,一般会形成再压缩激波.在大攻角条件下,由机身下方翻转上来的亚音速气流与机翼上表面超音速气流接触,因亚音速气流压力高于超音速气流,因此产生高背压斜激波,以达到压力平衡.我们发现,高背压斜激波正好构成机翼上的再压缩激波.在较大攻角条件下,机翼脱体激波、再压缩激波以及超音速与亚音速气流之间的滑移线,为满足压力平衡,交于前缘某点,形成特有的脱体激波/再压缩激波/滑移线干扰结构.计算表明,该滑移线内在的开尔文-亥姆赫兹不稳定性会导致新的非定常现象与气动噪声.A numerical simulation for a supersonic flow around a F15 fighter model shows a new triple flow structure at the high angle of attack. This triple flow structure is composed of a detached shock wave ahead of the leading edge, a recompression shock wave on the wing and a slipline downstream of the recompression shock wave. The role of the angle of attack on the pattern of this structure is identified. It is shown that when the angle of attack is high enough, the three discontinuities intersect the leading edge at some point. The Kelvin Helmholtz instability for the slipline would provide a new source of noise.

关 键 词：超音速流动 大攻角 激波 滑移线 

分 类 号：V211.4[航空宇航科学与技术—航空宇航推进理论与工程]