Scale-adaptive simulation of flow past wavy cylinders at a subcritical Reynolds number

• Published in: Acta mechanica Sinica Vol. 27; no. 5; pp. 660 - 667
• Main Authors: Zhao, Rui, Xu, Jing-Lei, Yan, Chao, Yu, Jian
• Format: Journal Article
• Language: English
• Published: Heidelberg The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences 01.10.2011
• Subjects: Amplitudes; Classical and Continuum Physics; Computational fluid dynamics; Computational Intelligence; Computer simulation; Cylinders; Engineering; Engineering Fluid Dynamics; Fluid flow; Research Paper; Reynolds number; Strouhal数; Theoretical and Applied Mechanics; Vortex-induced vibrations; Vortices; 亚临界雷诺数; 实验测量; 平均流场; 波浪; 涡结构; 自由剪切层; 自适应模拟; Vortex shedding; Vibration control; Drag reduction; SAS; Wavy cylinders
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-011-0490-4

The Xu ＆ Yan scale-adaptive simulation （XYSAS） model is employed to simulate the flows past wavy cylinders at Reynolds number 8 × 10 3.This approach yields results in good agreement with experimental measurements.The mean flow field and near wake vortex structure are replicated and compared with that of a corresponding circular cylinder.The effects of wavelength ratios λ/D m from 3 to 7,together with the amplitude ratios a /D m of 0.091 and 0.25,are fully investigated.Owing to the wavy configuration,a maximum reduction of Strouhal number and root-meansquare （r.m.s） fluctuating lift coefficients are up to 50% and 92%,respectively,which means the vortex induced vibration （VIV） could be effectively alleviated at certain larger values of λ/D m and a /D m.Also,the drag coefficients can be reduced by 30%.It is found that the flow field presents contrary patterns with the increase of λ/D m.The free shear layer becomes much more stable and rolls up into mature vortex only further downstream when λ/D m falls in the range of 5-7.The amplitude ratio a /D m greatly changes the separation line,and subsequently influences the wake structures.