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| 超声速膨胀角入射激波/湍流边界层干扰直接数值模拟 | |
| 引用本文： | 童福林,孙东,袁先旭,李新亮. 超声速膨胀角入射激波/湍流边界层干扰直接数值模拟[J]. 航空学报, 2020, 41(3): 123328-123328. DOI: 10.7527/S1000-6893.2019.23328 |
| 作者姓名： | 童福林 孙东 袁先旭 李新亮 |
| 作者单位： | 1. 中国空气动力研究与发展中心 空气动力学国家重点实验室, 绵阳 621000;2. 中国科学院 力学研究所 高温气体动力学重点实验室, 北京 100190;3. 中国空气动力研究与发展中心 计算空气动力研究所, 绵阳 621000;4. 中国科学院大学 工程科学学院, 北京 100049 |
| 基金项目： | 国家自然科学基金;国家重点研发计划 |
| 摘 要： | 为了揭示膨胀效应对激波/湍流边界层干扰区内复杂流动现象的影响规律，采用直接数值模拟方法对来流马赫数2.9、30°激波角的入射激波与10°膨胀角湍流边界层相互作用问题进行了数值研究。系统地探讨了激波入射点分别位于膨胀角上游、膨胀角角点和膨胀角下游3种工况下膨胀角干扰区内若干基本流动现象，如分离泡、物面压力脉动及激波非定常运动、湍流边界层统计特性和相干结构动力学过程等。结果表明，激波入射点流向位置改变对分离区流向和法向尺度的影响显著，尤其是当激波入射点位于角点及其下游区域。研究发现，膨胀角干扰区内物面压力脉动强度急剧减小，分离区内压力波向下游传播速度将降低而在膨胀区内将升高，膨胀效应极大地抑制了分离激波的低频振荡运动。相较于入射激波与平板湍流边界层干扰，入射激波流向位置改变对膨胀角再附区速度剖面对数区及尾迹区影响显著，将导致其内层结构参数升高而外层降低，近壁区内将呈现远离一组元湍流状态的趋势。此外，流向速度脉动场本征正交分解分析指出，主模态空间结构集中在分离激波及剪切层根部附近而高阶模态以边界层内小尺度正负交替脉动结构为主。低阶重构流场结果表明，前者对应为分离泡低频膨胀/收缩过程而后者表征为分离泡高频脉动。 |
| 关 键 词： | 激波/湍流边界层干扰 膨胀角 本征正交分解 直接数值模拟 超声速 |
| 收稿时间： | 2019-08-02 |
| 修稿时间： | 2019-10-12 |
Direct numerical simulation of impinging shock wave/turbulent boundary layer interactions in a supersonic expansion corner |
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| TONG Fulin,SUN Dong,YUAN Xianxu,LI Xinliang. Direct numerical simulation of impinging shock wave/turbulent boundary layer interactions in a supersonic expansion corner[J]. Acta Aeronautica et Astronautica Sinica, 2020, 41(3): 123328-123328. DOI: 10.7527/S1000-6893.2019.23328 | |
| Authors: | TONG Fulin SUN Dong YUAN Xianxu LI Xinliang |
| Affiliation: | 1. State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang 621000, China;2. State Key Laboratory of High Temperature Gas Dynamics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China;3. Computational Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China;4. School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China |
| Abstract: | To reveal the expansion effects on the complicated flow phenomena, direct numerical simulations of impinging shock wave and turbulent boundary layer interaction for the incident shock of 30° at Mach number 2.9 in an expansion corner of 10° are performed. Three cases, corresponding to the impingement point upstream, in the vicinity and downstream of the expansion corner, are systematically studied to investigate the intricate flow mechanisms, including separation bubble, fluctuating wall pressure and unsteady motion of shock wave, statistical characteristics of turbulent boundary layer, and dynamical processes of coherent structure. The results indicate that the variations of impingement point have significant influence on the streamwise and wall-normal scales of separation bubble, especially when the shock wave is located at the corner or in its downstream region. It is found that the intensities of fluctuating wall pressure are dramatically reduced in the expansion region, and the downstream-propagating speed of wall pressure waves is significantly reduced in the separation region and relatively accelerated in the expansion region. The low-frequency unsteady oscillations of separated shock waves are dramatically suppressed by the expansion effects. Compared with the inter-actions between oblique shock-wave and turbulent boundary layer of flat-plate, the logarithmic and wake regions of the mean velocity profile in the reattachment boundary layer are evidently changed by the variations of impingement point. The structure parameter for the Reynolds stress is increased in the inner region and decreased in the outer layer. The anisotropy invariant maps suggest that the turbulence in the near wall region gradually deviates from the one-component state. Furthermore, the proper orthogonal decomposition analysis of the fluctuating streamwise velocity indicates that the dominant mode is associated with the separated shock and the foot of separated shear layer, whereas the high-order mode is characterized by the small-scale sign-alternating fluctuation structures. The obtained low-order reconstruction illustrates that the dominant mode is corresponding to the dilation and contraction of separation bubble, but the high-order mode is associated with the high frequency ossification of separation bubble. |
| Keywords: | shock wave/turbulent boundary layer interaction expansion corner proper orthogonal decomposition direct numerical simulation supersonic |
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