亚-超声速混合层流动特征研究

Study on Flow Characteristic of Sub-/Super-Sonic Mixing Layer

为了获得亚-超声速混合层速度分布、压力分布及混合层发展的基本特征,开展试验与数值模拟研究。试验中采用粒子图像测速技术PIV测量二维速度分布;数值研究中,湍流模型为标准k-ω,考虑亚-超声速混合层的压缩性影响,开展稳态流场特征模拟。亚声速气流马赫数为0.11,超声速气流马赫数为1.32。研究结果表明:混合层具有非稳态特征,分界面发展经历近似线性发展、褶皱与变形、破碎;时均特征为混合层沿流向近似呈现线性增长,增长率为0.135;混合层内速度和总压分布具有相似性特征。

In order to obtain the flow characteristics of sub-super-sonic mixing layer including velocity distribution,pressure distribution and development of mixing layer,experimental and numerical investigations were conducted.PIV technique was employed to measure the two-dimensional velocity distribution in the experiment while the standard k-ω turbulent considering the effect of compressibility was adopted to simulate the flow characteristic of mixing layer.The Mach number of subsonic stream and supersonic one was 0.11 and 1.32,respectively.The results show the flow of mixing layer is temporally transient.The interface between two streams lies initially as an approximately line segment;afterward,it becomes wrinkled and distorted;finally,it breaks up.The mixing layer develops linearly along streamwise direction in the time averaged velocity field with a growth rate of 0.135.The velocity and total pressure distributions in the mixing layer are self-similar.