Large-eddy simulation-based shape optimization for mitigating turbulent wakes of a bluff body using the regularized ensemble Kalman method
文献类型：期刊论文
| 作者 | Zhang XL(张鑫磊)1,2; Zhang FS(张风顺)1,2; Li ZB(李曌斌)1,2; Yang XL(杨晓雷)1,2 ; He GW(何国威)1,2
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| 刊名 | JOURNAL OF FLUID MECHANICS
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| 出版日期 | 2024-12-12 |
| 卷号 | 1001页码:30 |
| 关键词 | turbulence control wakes chaos |
| ISSN号 | 0022-1120 |
| DOI | 10.1017/jfm.2024.1090 |
| 通讯作者 | He, Guowei(hgw@lnm.imech.ac.cn) |
| 英文摘要 | In this work, the shape of a bluff body is optimized to mitigate velocity fluctuations of turbulent wake flows based on large-eddy simulations (LES). The Reynolds-averaged Navier-Stokes method fails to capture velocity fluctuations, while direct numerical simulations are computationally prohibitive. This necessitates using the LES method for shape optimization given its scale-resolving capability and relatively affordable computational cost. However, using LES for optimization faces challenges in sensitivity estimation as the chaotic nature of turbulent flows can lead to the blowup of the conventional adjoint-based gradient. Here, we propose using the regularized ensemble Kalman method for the LES-based optimization. The method is a statistical optimization approach that uses the sample covariance between geometric parameters and LES predictions to estimate the model gradient, circumventing the blowup issue of the adjoint method for chaotic systems. Moreover, the method allows for the imposition of smoothness constraints with one additional regularization step. The ensemble-based gradient is first evaluated for the Lorenz system, demonstrating its accuracy in the gradient calculation of the chaotic problem. Further, with the proposed method, the cylinder is optimized to be an asymmetric oval, which significantly reduces turbulent kinetic energy and meander amplitudes in the wake flows. The spectral analysis methods are used to characterize the flow field around the optimized shape, identifying large-scale flow structures responsible for the reduction in velocity fluctuations. Furthermore, it is found that the velocity difference in the shear layer is decreased with the shape change, which alleviates the Kelvin-Helmholtz instability and the wake meandering. |
| 分类号 | 一类/力学重要期刊 |
| WOS关键词 | SENSITIVITY-ANALYSIS ; FLOW ; GRADIENT ; COMPLEX ; NOISE ; CHAOS ; 3D |
| 资助项目 | NSFC Basic Science Center Program for 'Multiscale problems in nonlinear mechanics'[11988102] ; National Natural Science Foundation of China[12102435] ; CAST[2022QNRC001] |
| WOS研究方向 | Mechanics ; Physics |
| 语种 | 英语 |
| WOS记录号 | WOS:001374915500001 |
| 资助机构 | NSFC Basic Science Center Program for 'Multiscale problems in nonlinear mechanics' ; National Natural Science Foundation of China ; CAST |
| 其他责任者 | He, Guowei |
| 源URL | [http://dspace.imech.ac.cn/handle/311007/97789]  |
| 专题 | 力学研究所_非线性力学国家重点实验室 |
| 作者单位 | 1.Univ Chinese Acad Sci, Sch Engn Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, Inst Mech, State Key Lab Nonlinear Mech, Beijing 100049, Peoples R China; |
| 推荐引用方式 GB/T 7714 | Zhang XL,Zhang FS,Li ZB,et al. Large-eddy simulation-based shape optimization for mitigating turbulent wakes of a bluff body using the regularized ensemble Kalman method[J]. JOURNAL OF FLUID MECHANICS,2024,1001:30. |
| APA | 张鑫磊,张风顺,李曌斌,杨晓雷,&何国威.(2024).Large-eddy simulation-based shape optimization for mitigating turbulent wakes of a bluff body using the regularized ensemble Kalman method.JOURNAL OF FLUID MECHANICS,1001,30. |
| MLA | 张鑫磊,et al."Large-eddy simulation-based shape optimization for mitigating turbulent wakes of a bluff body using the regularized ensemble Kalman method".JOURNAL OF FLUID MECHANICS 1001(2024):30. |
入库方式： OAI收割
来源：力学研究所
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