Resolvent Analysis of Compressible Laminar and Turbulent Cavity Flows
Resolvent Analysis of Compressible Laminar and Turbulent Cavity Flows
复制标题
可压缩层流和湍流空腔流的解析分析
作者：
Yiyang Sun;Qiong Liu;L. Cattafesta;L. Ukeiley;K. Taira
目前的工作演示了解决分析的使用，以获得开腔流动的物理见解。在给定稳定基态的情况下，根据响应和强迫模式以及放大增益，解析分析确定了对谐波强迫的流动响应。响应和强迫模态揭示了与这一放大过程相关的空间结构。在本研究中，我们对长深比为$L/D=6$的矩形空腔在自由流马赫数为$ m_inty =0.6$时的层流和湍流进行了解析分析。基于基态的主要不稳定性，引入了一个折现参数用于解析分析，以考察有限时间窗内的谐波特性。我们首先揭示了潜在的流动物理，并解释了层流在$Re_D = 502$处的发现。层流的这些发现可以推广到更高雷诺数$Re_D = 10^4$的更实际的空腔流例子中。层流和湍流空腔的响应和强迫模态特征与层流分析的空间结构相似。我们进一步发现，在湍流情况下，流动响应中的能量放大与高频有关，而在层流情况下，流动对低频激励的响应更大。这些解决方案分析的结果为流量控制研究提供了有价值的见解，包括执行器和传感器的参数选择和位置。
The present work demonstrates the use of resolvent analysis to obtain physical insights for open-cavity flows. Resolvent analysis identifies the flow response to harmonic forcing, given a steady base state, in terms of the response and forcing modes and the amplification gain. The response and forcing modes reveal the spatial structures associated with this amplification process. In this study, we perform resolvent analysis on both laminar and turbulent flows over a rectangular cavity with length-to-depth ratio of $L/D=6$ at a free stream Mach number of $M_infty=0.6$ in a spanwise periodic setting. Based on the dominant instability of the base state, a discount parameter is introduced to resolvent analysis to examine the harmonic characteristics over a finite-time window. We first uncover the underlying flow physics and interpret findings from laminar flow at $Re_D = 502$. These findings from laminar flow are extended to a more practical cavity flow example at a much higher Reynolds number of $Re_D = 10^4$. The features of response and forcing modes from the laminar and turbulent cavity flows are similar to the spatial structures from the laminar analysis. We further find that the large amplification of energy in flow response is associated with high frequency for turbulent flow, while the flow is more responsive to low frequency excitation in the laminar case. These findings from resolvent analysis provide valuable insights for flow control studies with regard to parameter selection and placement of actuators and sensors.
影响因子：
3.7
作者：
McKeon, B. J.;Sharma, A. S.
通讯作者：
Sharma, A. S.