کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7054533 | 1458019 | 2018 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Heat transport enhancement and scaling law transition in two-dimensional Rayleigh-Bénard convection with rectangular-type roughness
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Heat transport enhancement and scaling law transition in two-dimensional Rayleigh-Bénard convection with rectangular-type roughness Heat transport enhancement and scaling law transition in two-dimensional Rayleigh-Bénard convection with rectangular-type roughness](/preview/png/7054533.png)
چکیده انگلیسی
Direct numerical simulations (DNS) of Rayleigh-Bénard convection are performed in two-dimensional (2-D) square cavities with rough top and bottom plates. The roughness is introduced by setting heated/cooled rectangular elements called fins equidistantly onto lower/upper plates. The Rayleigh numbers (Ra) range from 107 to 1010. Different numbers of fins (S) are used with Prandtl number (Pr) fixed to 1. The Pr effect is also investigated for fixed S=8, with Pr varied from 0.71 to 34.1. It is found that in all roughness configurations, the heat transport is significantly enhanced when Ra exceeds a critical value. The power-law scalings of the Nusselt number (Nu) versus Ra keep in change in the studied Ra range for all Pr and S, with most of the exponents within [1/3,1/2], larger than those in smooth cases. In addition, we find Nu increases monotonically with Pr when Pr⩾1 and Ra is moderate for S=8. The dynamics of plumes, the flow structures between the fins and in the bulk, as well as the turbulence dissipation rates are found to be greatly influenced by the presence of fins, which are responsible for the heat transport enhancement, as well as the change in Nuâ¼Ra power-law scalings.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 121, June 2018, Pages 872-883
Journal: International Journal of Heat and Mass Transfer - Volume 121, June 2018, Pages 872-883
نویسندگان
Bo-Lun Xu, Qi Wang, Zhen-Hua Wan, Rui Yan, De-Jun Sun,