引入DMD方法研究有/无控气流分离的动态结构
收稿日期: 2016-10-21
修回日期: 2016-11-18
网络出版日期: 2017-01-11
基金资助
国家自然科学基金（51176072）
Introducing DMD method to study dynamic structures of flow separation with and without control
Received date: 2016-10-21
Revised date: 2016-11-18
Online published: 2017-01-11
Supported by
National Natural Science Foundation of China (51176072)
为分析非定常流动控制技术抑制分离流的机理，对弯曲扩压通道的试验模型进行了数值模拟，针对扩压通道在无控和采用最佳射流频率状态下的计算结果引入了动力模态分解（DMD）技术进行分析。通过DMD技术能够将包含时空信息的扩压通道复杂流场进行分解，捕获流场包含的动力信息和对应的拟序流动结构。将无控和有控流场分解的结果进行对比分析后表明：采用有效激励措施时，和脱落涡频率一致的涡系对流场的影响更加突显，流场整体上表现得更加有序；非定常控制抑制了一部分涡的增长，使得各模态整体上更加稳定；而有控流场占主导地位的涡系结构相比无控流场较为有序，且对主流区未形成明显的直接影响。
关键词： 流动分离; 非定常; 流动控制; 拟序结构; 动力模态分解(DMD)
洪树立 , 黄国平 . 引入DMD方法研究有/无控气流分离的动态结构[J]. 航空学报, 2017 , 38(8) : 120876 -120876 . DOI: 10.7527/S1000-6893.2016.120876
To analyze the mechanism of depressing flow separation with unsteady flow control technology, a numerical simulation for the experimental model of the divergent channel is carried out. Dynamic mode decomposition (DMD) technology is adopted to study the flow field of the curved divergent channel with and without pulsed jet control. With DMD technology, the complex flow field of the divergent channel containing spatial and temporal information can be decomposed hierarchically, and dynamical information as well as spatial coherent structure corresponding to the vortex can be captured and rendered. A comparison of the decomposed flow fields with and without control shows that with effective excitation, the coherent structure with the frequency approximating the frequency of the shedding vortex becomes more dominant in the initial flow field, and the overall flow field turns out be to more ordered. Some coherent structures, decomposed from flow field without control, are suppressed to make all modes more steady. The dominant structure of the controlled flow field has no obvious influence on the main flow.
[1] RIVIR R B, SONDERGAARD R, BONS J P, et al. Passive and active control of separation in gas turbines:AIAA-2000-2235[R]. Reston, VA:AIAA, 2000.
[2] HERGT A, MEYER R, ENGEL K. Experimental investigation of flow control in compressor cascades:GT-2006-90415[R]. New York:ASME, 2006.
[3] GREENBLATT D, WYGNANSKI I J. The control of flow separation by periodic excitation[J]. Progress in Aerospace Sciences, 2000, 36(7):487-545.
[4] WYGNANSKI I J. The variables affecting the control of separation by periodic excitation:AIAA-2004-2505[R]. Reston, VA:AIAA, 2004.
[5] SEⅡCHI I, MASATO F, KENICHIRO I, et al. Vortical flow structure and loss generation process in a transonic centrifugal compressor impeller:GT-2007-27791[R]. New York:ASME, 2007.
[6] HASHMI S, QIAO W Y, CHEN P P. Prediction of hub corner stall characteristics of a highly loaded low speed single stage fan[J]. Journal of Thermal Science, 2011, 20(2):106-114.
[7] ADRIAN R J, MEINHART C D, TOMKINS C D. Vortex organization in the outer region of turbulent boundary layer[J]. Journal of Fluid Mechanics, 2000, 422:1-54.
[8] DENNIS D J C, NICKELS T B. Experimental measurement of large-scale three-dimensional structures in a turbulent boundary layer. Part 1:Vortex packets[J]. Journal of Fluid Mechanics, 2011, 673:180-217.
[9] FENG L H, WANG J J, PAN C. Proper orthogonal decomposition analysis of vortex dynamics of a circular cylinder under synthetic jet control[J]. Physics of Fluid, 2011, 23:014106.
[10] 朱剑锋, 黄国平, 傅鑫, 等. 基于POD方法的弯曲扩压通道分离流控制的时空特性分析[J]. 航空学报, 2014, 35(4):921-932. ZHU J F, HUANG G P, FU X, et al. Spatiotemporal characteristics analysis for controlling flow separation in divergent curved channels with POD method[J]. Acta Aeronautica et Astronautica Sinica, 2014, 35(4):921-932(in Chinese).
[11] MEZI? I. Analysis of fluid flows via spectral properties of Koopman operator[J]. Annual Review of Fluid Mechanics, 2013, 45(1):357-378.
[12] ZHANG W, WANG Y, QIAN Y H. Stability analysis for flow past a cylinder via lattice Boltzmann method and dynamic mode decomposition[J]. Chinese Physics B, 2015, 24(6):378-384.
[13] ROWLEY C W, MEZI? I, BAGHERI S, et al. Spectral analysis of nonlinear flows[J]. Journal of Fluid Mechanics, 2009, 641:115-127.
[14] SCHMID P J. Dynamic mode decomposition of numerical and experimental data[J]. Journal of Fluid Mechanics, 2010, 656:5-28.
[15] SCHMID P J. Application of the dynamic mode decomposition to experimental[J]. Experiments in Fluids, 2011, 50(4):1123-1130.
[16] ZHANG Q S, LIU Y Z, WANG S F. The identification of coherent structures using proper orthogonal decomposition and dynamic mode decomposition[J]. Journal of Fluids and Structures, 2014, 49:53-72.
[17] SEENA A, SUNG H J. Dynamic mode decomposition of turbulent cavity flows for self-sustained oscillations[J]. International Journal of Heat & Fluid Flow, 2011, 32(6):1098-1110.
[18] NASTASE I, MEALEM A, EI HASSAN M. Image processing analysis of vortex dynamics of lobed jets from three-dimensional diffusers[J]. Fluid Dynamics Research, 2011, 43:065502.
[19] 胡海岩. 机械振动基础[M]. 哈尔滨:哈尔滨工业大学出版社, 2004. HU H Y. Mechanical vibration foundation[M]. Harbin:Harbin Institute of Technology Press, 2004(in Chinese).
[20] GREENBAUM A. Iterative methods for solving linear system[M]. Philadelphia:SIAM, 1997.
[21] SCHMID P J, LI L, JUNIPER M P, et al. Applications of the dynamic mode decomposition[J]. Theoretical and Computational Fluid Dynamics, 2011, 25(1):249-259.
[22] 朱剑锋, 黄国平, 傅鑫, 等. 一种控制气流分离的无源微脉冲射流技术研究[J]. 航空学报, 2013, 34(8):1757-1767. ZHU J F, HUANG G P, FU X, et al. Investigation of technology for controlling flow separation by micro-pulsed-jet without external device[J]. Acta Aeronautica et Astronautica Sinica, 2013, 34(8):1757-1767(in Chinese).
[23] 朱剑锋, 黄国平, 傅鑫, 等. 脉冲射流控制弯曲扩压管道流动分离的特点[J]. 航空动力学报, 2015, 30(12):2942-2948. ZHU J F, HUANG G P, FU X, et al. Characteristic of controlling flow separation in divergent curved channels by pulsed jet[J]. Journal of Aerospace Power, 2015, 30(12):2942-2948(in Chinese).
[24] 潘翀, 陈皇, 王晋军. 复杂流场的动力学模态分解[C]//第八届全国实验流体力学学术会议. 北京:中国学术期刊电子出版社, 2010:77-82. PAN C, CHEN H, WANG J J. Dynamic modal decomposition of complex flow field[C]//The Eighth National Conference on Experimental Fluid Mechanics. Beijing:China Academic Journal Electronic Publishing House, 2010:77-82(in Chinese).
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