声学超表面抑制高速边界层内宽频不稳定模态研究  

Acoustic metasurfaces for stabilization of broadband unstable modes in high speed boundary layer

作　　者：王蔚彰 孔维萱[2] 严昊 赵瑞[1] WANG Weizhang;KONG Weixuan;YAN Hao;ZHAO Rui(School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China;Beijing Institute of Space Long March Vehicle,Beijing 100076,China)

机构地区：[1]北京理工大学宇航学院,北京100081 [2]北京航天长征飞行器研究所,北京100076

出　　处：《北京航空航天大学学报》2023年第2期388-396,共9页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(11872116,11991030,11991033);火箭创新预研基金。

摘　　要：以声学超表面为研究对象,使用线性稳定性理论(LST),研究了声学超表面导纳相位与幅值对超声速平板边界层内宽频不稳定模态的影响规律。结果表明:当导纳相位θ接近0.5π时,第1模态被抑制的同时第2模态会被激发,且在较低频率范围内导纳幅值的增大能够使第1模态更加稳定;当导纳相位θ接近π时,可抑制第2模态但同时激发第1模态;整体上,导纳幅值越大,对不稳定模态的抑制或激发效果越明显。在此基础上,结合缝隙几何参数对导纳的影响,提出一种可实现性宽频抑制方案,通过分段设计声学超表面微结构的几何尺寸,实现了同时抑制第1模态和高频第2模态的目标,并使用eN方法验证了转捩抑制效果。The influences of the admittance phase and amplitude of acoustic metasurfaces on the broadband unstable modes in a high-speed flat plate boundary layer are analyzed using linear stability theory(LST).It is demonstrated that when the admittance phase goes to 0.5π,the first mode is suppressed while the second mode is simultaneously motivated.Moreover,the increase of amplitude within the lower frequency range can enhance the stability of the first mode.The Mack second mode is suppressed when the admittance phase tends toπ,while the first mode is motivated.Generally,the larger the admittance amplitude is,the more obvious the suppression or excitation effect of unstable modes becomes.Besides,combined with the effect of aperture geometry parameters on the admittance,an engineering realizable broadband acoustic metasurface is proposed to suppress both the first and Mack second modes in Mach 4 boundary layer flow.It elaborately designs the piecewise microstructures to achieve the local favorite admittance phase and amplitude,and its performance is verified by the eNmethod.

关 键 词：声学超表面 不稳定模态 线性稳定性分析 边界层转捩 超声速流动 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程] O354.4[理学—流体力学]