Forced turbulent fountain flow behaviour
Forced turbulent fountain flow behaviour
复制标题
强迫湍流喷泉流动行为
DOI：
10.1017/s0022112010005872
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发表时间：
2011-02
影响因子：
3.7
通讯作者：
N. Williamson
中科院分区：
文献类型：
--
作者：
S. W. Armfield;林文贤;N. Williamson
湍流喷泉流的数值模拟被用来调查的重要的能量和质量传递机制中存在的强制喷泉流制度，据报道，存在于弗劳德数（Fr）大于3。该流动相当于具有三个流动流的负浮力射流，即内部上升流（IF）、外部下降流（OF）和周围环境流体（AF）。给出了雷诺数Re = 3350时Fr = 4和7的模拟结果。平均喷泉穿透高度尺度与以前报道的关系Zm/R 0 = 2.46Fr，其中R 0是源半径，但背后的假设分析推导的关系不支持本结果。结果表明，OF可能是相对较好地描述了一个纯线羽流周围的IF，但由于从IF进入OF的流的不稳定的脉冲行为具有较高的夹带的动态。纯羽流的长度尺度似乎适用于在Fr = 7的OF和自相似程度的存在。与先前结果的比较表明，IF在Fr = 7时没有完全发展，并且从OF夹带到IF中可能直到Fr > 15才发生。
Numerical simulations of turbulent fountain flow are used to investigate the important energy and mass transfer mechanisms present in the forced fountain flow regime, which has been reported to exist at Froude numbers (Fr) greater than 3. The flow is equivalent to a negatively buoyant jet with three flow streams, the inner upflow (IF), the outer downflow (OF) and the surrounding ambient fluid (AF). Simulation results are presented for Fr = 4 and 7 at Reynolds number Re = 3350. The mean fountain penetration height scales with the previously reported relation Zm/R0 = 2.46Fr, where R0 is the source radius, but the assumptions behind analytical derivations of the relation are not supported by the present results. The results suggest that the OF may be relatively well described by the dynamics of a pure line plume surrounding the IF but with higher entrainment owing to the unsteady pulsing behaviour of the flow entering the OF from the IF. The length scale for a pure plume appears to apply at Fr = 7 in the OF and a degree of self-similarity exists. Comparisons with previous results suggest the IF is not fully developed at Fr = 7 and entrainment into the IF from the OF may not occur until Fr > 15.
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影响因子：
3.7
作者：
W. Baines;J. S. Turner;I. Campbell
通讯作者：
W. Baines;J. S. Turner;I. Campbell
DOI：
10.1017/s0022112099006953
发表时间：
2000-01
期刊：
J.Fluid Mech.
影响因子：
--
作者：
Wenxian Lin;S.W.Armfield
通讯作者：
S.W.Armfield
影响因子：
2.3
作者：
G. Abraham
通讯作者：
G. Abraham
影响因子：
2.4
作者：
L. Pantzlaff;Richard M. Lueptow
通讯作者：
L. Pantzlaff;Richard M. Lueptow
影响因子：
3.7
作者：
Lynn J. Bloomfield;R. C. Kerr
通讯作者：
Lynn J. Bloomfield;R. C. Kerr