摘要
在超声速风洞中开展了湍流边界层与圆柱相互作用流场研究,试验马赫数为3.4和3.8。圆柱安装在试验段底板上,安装位置的边界层为充分发展的湍流边界层,研究了圆柱直径和高度对流场结构和压力脉动的影响。采用基于纳米示踪的平面激光散射(NPLS)技术获取了流向和展向流场精细结构,激波系和马蹄涡结构均可清晰分辨。通过展向流场图像可以发现干扰区内激波与湍流结构的相互作用具有明显的非定常性。采用动态压力传感器测量了圆柱前方相互作用区域的压力脉动特性,在激波足区域压力呈现11~38 kHz的宽频分布,推测主要由激波足与涡结构相互作用及滞止区涡结构的破碎引起。随着圆柱高度的增加,激波足附近测点对应的特征频率有所降低;上游测点则发现了0~3 kHz低频区能量的增强,这主要是由分离区引起的,表明在一定高度范围内高度的增加增强了流动分离。
The flow field of interactions between the turbulent boundary layer and cylinders was studied in a supersonic wind tunnel with the Mach numbers 3.4 and 3.8 respectively.The cylinder was mounted on the floor of the test section,and the boundary layer was fully developed at the installation position.Besides,the influence of the diameter and height of the cylinders on the flow field structure and pressure fluctuations was studied,and the fine structures of the flow field in the streamwise and the spanwise plane were obtained using Nano-tracer Planar Laser Scattering(NPLS)technique.The shock system and the horseshoe vortex structure could be clearly distinguished.It could be found that the interactions between the shock wave and the turbulence structures presented unsteady characteristics through images of the spanwise plane.The dynamic pressure transducers were used to measure the pressure pulsation characteristics of the interaction region in front of the cylinder.In the shock foot region,the pressure pulsation characteristics ranged from 11 kHz to 38 kHz,which was speculated to be mainly caused by the interactions between shock foot and vortex structure,and the breakup of vortex structures in the stagnation region.With increasing height,the characteristic frequency corresponding to the peak value of the measuring point near the shock foot decreased.The energy enhancement in the low frequency range of 0-3 kHz was found at the upstream points,which was mainly caused by the separation zone,indicating that the increase of height enhanced the flow separation.
作者
冈敦殿
易仕和
米琦
牛海波
GANG Dundian;YI Shihe;MI Qi;NIU Haibo(College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第1期116-123,共8页
Acta Aeronautica et Astronautica Sinica
基金
国家重点研发计划(2019YFA0405300)
国家自然科学基金(11902354)。
关键词
超声速圆柱绕流
激波/边界层相互作用
非定常特性
压力脉动
NPLS
supersonic flow over cylinders
shock wave/boundary layer interactions
unsteady characteristics
pressure fluctuations
NPLS
