کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4992981 | 1457473 | 2017 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Penetration height of transitional round fountains in a linearly stratified fluid
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Penetration height of transitional round fountains in a linearly stratified fluid Penetration height of transitional round fountains in a linearly stratified fluid](/preview/png/4992981.png)
چکیده انگلیسی
The transition to asymmetry of transitional fountains is further complicated by the stratification of the ambient fluid. In this study, a series of three-dimensional direct numerical simulations were carried out for transitional round fountains in linearly-stratified fluids over the ranges of 100 ⤠Re ⤠400, 1 ⤠Fr ⤠8 and 0.0 ⤠s ⤠0.3, where Fr, Re and s are the Froude, Reynolds, and dimensionless temperature stratification parameters, respectively, to examine, both qualitatively and quantitatively, the effect of these parameters on their axisymmetric transition and their maximum penetration heights. The results show that when Fr or Re are small enough, a fountain remains axisymmetric for all time; however, when Fr or Re are increased sufficiently, the fountain will be axisymmetric initially, before becoming asymmetric and unsteady, ultimately reaching a fully developed quasi-steady stage when the maximum fountain penetration height fluctuates over a constant, time-average, value. The stratification is found to play a positive role to stabilize the flow and to reduce or even to eliminate the asymmetric behavior. The numerical results were also used to develop a series of scaling relations, in conjunction with the scalings obtained with dimensional analysis, for the initial and time-averaged fountain penetration heights, and the time for the fountain to attain the initial penetration height. It is further found that in general these characteristic parameters are strongly dependent on Fr and s, while only weakly dependent on Re.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Communications in Heat and Mass Transfer - Volume 81, February 2017, Pages 79-91
Journal: International Communications in Heat and Mass Transfer - Volume 81, February 2017, Pages 79-91
نویسندگان
Wenfeng Gao, Wenxian Lin, Tao Liu, S.W. Armfield, Ming Li,