水-气界面下低速流体条带的喷射行为
Streak-ejections under sheared air-water interface
查看参考文献12篇
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文摘
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对剪切水-气界面下湍流低速条带的喷射现象进行了细致的观测。喷射过程中，条带的一部分迅速离开水面近区下侵，与深层高速流动发生激烈的相互作用。这意味着条带喷射对水面剪切层中的湍流输运有重要影响。根据流动显示的图像资料获得的定量结果揭示出喷射行为的基本特征，包括喷射频率、喷射流体的轨迹和速度分布等。文中将这些特征与固壁湍流边界层中的对应情形作了比较。实验观察和喷射、猝发事件的时间分布特点表明，低速条带喷射是猝发过程的组成部分，喷射的时间间隔一般显著小于猝发，两种现象的出现都具有很强的随机性。将喷射与湍动能产生率的空间分布作比较，它们的形状极为相似，反映出喷射过程可能是水面附近湍流的主要贡献者。 |
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其他语种文摘
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Described in this paper are careful visual and quantitative studies on ejection phenomena of low-speed streaks under sheared air-water interface. During an ejection process, a portion of low-speed streaks rapidly migrates away from the water surface, and subsequently breaks down in a violent interaction with faster flow, demonstrating that such processes play an important role in the turbulent transport between the interface and deeper layers. Quantitative data derived from flow-visualization pictures reveals fundamental features in ejection events, including frequency, trajectories and velocities of ejected fluid. Comparisons of these findings with the corresponding features of near-wall streak-ejections are also made. Temporal distributions of ejection and bursting events, together with the visual observations, indicateo that a burst may involve either a single ejection or multiple ejections closely grouped together, and the time interval between ejection events is generally much less than that between bursts. Furthermore, the occurrence of both ejections and bursts exhibits intense randomness. The comparison of a turbulence production profile with the corresponding frequency distribution of ejections is presented. The remarkable agreement in the shape of two curves strongly suggests that ejection processes is the chief contributor of turbulent kinetic energy. |
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来源
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力学学报
,2002,34(3):305-313 【核心库】
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关键词
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剪切水-气界面
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低速条带
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喷射
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猝发
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流动显示
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地址
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中国科学院力学研究所, 北京, 100080
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语种
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中文 |
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文献类型
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研究性论文 |
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ISSN
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0459-1879 |
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学科
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力学 |
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基金
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国家自然科学基金
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文献收藏号
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CSCD:1013440
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参考文献 共
12
共1页
|
|
1.
Kline S J. The structure of turbulent boundary layers.
J Fluid Mech,1967,30:741-773
|
CSCD被引
137
次
|
|
|
|
|
2.
Kline S J. Quasi-coherent structures in the turbulent boundary layer: Part I. Status report on a community-wide summary of the data.
Near-Wall Turbulence, Proc. Zoran Zaric Meml. Conf.,1989:200-217
|
CSCD被引
1
次
|
|
|
|
|
3.
Smith C R. The characteristics of low-speed streaks in the near-wall region of a turbulent boundary layer.
J Fluid Mech,1983,129:27-54
|
CSCD被引
30
次
|
|
|
|
|
4.
Smith C R. On the dynamics of near-wall turbulence.
Phil Trans R Soc Lond A,1991,336:131-175
|
CSCD被引
7
次
|
|
|
|
|
5.
Rashidi M. The effect of boundary conditions and shear rate on streak formation and breakdown in turbulent channel flows.
Phys Fluids,1990,2(10):1827-1838
|
CSCD被引
1
次
|
|
|
|
|
6.
Wang S F. An experimental study on turbulent coherent structures near a sheared air-water interface.
Acta Mechanica Sinica(in Eng),1999,15(4):289-298
|
CSCD被引
6
次
|
|
|
|
|
7.
Wang S F. Some characteristics of low-speed streaks under sheared air-water interfaces.
Acta Mechanica Sinica(in Eng),2001,17(2):115-124
|
CSCD被引
4
次
|
|
|
|
|
8.
Bogard D G. Burst detection with single-point velocity measurements.
J Fluid Mech,1986,162:389-413
|
CSCD被引
14
次
|
|
|
|
|
9.
Blackwelder R J. Scaling of the bursting frequency in turbulent boundary layers.
J Fluid Mech,1983,132:87-103
|
CSCD被引
1
次
|
|
|
|
|
10.
Willmarth W W. Study of turbulent structure with hot wires smaller than the viscous length.
J Fluid Mech,1984,142:121-149
|
CSCD被引
6
次
|
|
|
|
|
11.
Luchik T S. Timescale and structure of ejections and bursts in turbulent channel flows.
J Fluid Mech,1987,174:529-552
|
CSCD被引
14
次
|
|
|
|
|
12.
舒玮. 湍流边界层的猝发频率.
力学学报,1989,21(4):391-395
|
CSCD被引
5
次
|
|
|
|
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