| Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow | |
Wang YT(王业腾)1,2; Sun ZX(孙振旭)1 ; Ju SJ(鞠胜军)1; Guo DL(郭迪龙)1; Yin B(银波)1; Pan BY(潘博宇)1,2; Nan KW(南凯威)1,2; Yang GW(杨国伟)1
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| Corresponding Author | Sun, Zhenxu([email protected]) |
| Source Publication | PHYSICS OF FLUIDS
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| 2023-12-01 | |
| Volume | 35Issue:12Pages:13 |
| ISSN | 1070-6631 |
| Abstract | Micro-riblet is an efficient passive method for controlling turbulent boundary layers, with the potential to reduce frictional drag. In various applications within the transportation industry, flow separation is a prevalent flow phenomenon. However, the precise drag reduction performance of riblets in the presence of flow separation remains unclear. To address this, an inclined forward step model is proposed to investigate the interaction between riblet and upstream flow separation. The large eddy simulation (LES) method is applied to simulate the flow over geometries with different step angles and riblet positions. The results show riblets still reduce wall frictional resistance when subjected to the upstream flow separation. Remarkably, as the angle of the step increases from 0 degrees to 30 degrees, the drag reduction experiences an increment from 9.5% to 12.6%. From a turbulence statistics standpoint, riblets act to suppress the Reynold stress in the near-wall region and dampen ejection motions, thus weakening momentum exchange. Quadrant analysis reveals that with the augmentation of flow separation, the Q2 motion within the flow field intensifies, subsequently enhancing the riblet-induced drag reduction. Moreover, the position of the rib lets has a significant impact on the pressure drag. Riblets close to the point of separation enhance flow separation, altering the surface pressure distribution and thus increasing the resistance. The results reveal that when the riblets are positioned approximately 160 riblet heights away from the step, their effect on the upstream flow separation becomes negligible. The precise performance of riblets under complex flow conditions is important for their practical engineering application. |
| DOI | 10.1063/5.0183742 |
| Indexed By | SCI ; EI |
| Language | 英语 |
| WOS ID | WOS:001133686300007 |
| WOS Keyword | DIRECT NUMERICAL-SIMULATION ; TURBULENT-BOUNDARY-LAYER ; LARGE-EDDY SIMULATION |
| WOS Research Area | Mechanics ; Physics |
| WOS Subject | Mechanics ; Physics, Fluids & Plasmas |
| Funding Project | China National Railway Group Science and Technology Program grant ; CAS Project for Young Scientists in Basic Research[YSBR-045] ; [K2023J047] |
| Funding Organization | China National Railway Group Science and Technology Program grant ; CAS Project for Young Scientists in Basic Research |
| Classification | 一类/力学重要期刊 |
| Ranking | 1 |
| Contributor | Sun, Zhenxu |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/94022 |
| Collection | 流固耦合系统力学重点实验室 |
| Affiliation | 1.Inst Mech, Chinese Acad Sci, Key Lab Mech Fluid Solid Coupling Syst, Beijing, Peoples R China; 2.Univ Chinese Acad Sci, UCAS, Beijing, Peoples R China |
| Recommended Citation GB/T 7714 | Wang YT,Sun ZX,Ju SJ,et al. Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow[J]. PHYSICS OF FLUIDS,2023,35,12,:13.Rp_Au:Sun, Zhenxu |
| APA | 王业腾.,孙振旭.,鞠胜军.,郭迪龙.,银波.,...&杨国伟.(2023).Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow.PHYSICS OF FLUIDS,35(12),13. |
| MLA | 王业腾,et al."Drag reduction using riblets downstream of a high Reynolds number inclined forward step flow".PHYSICS OF FLUIDS 35.12(2023):13. |
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| Jp2023A216.pdf（3403KB） | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | View Download | |
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