Particle dispersion in a turbulent vortex core
Particle dispersion in a turbulent vortex core
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湍流涡核中的颗粒分散
DOI：
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发表时间：
2005
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通讯作者：
J. Marshall
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文献类型：
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作者：
J. Marshall
采用直接数值模拟的方法研究了柱状涡中湍流对颗粒弥散的影响。一种程序被用来产生初始条件，其中涡旋外部的湍流具有大尺度涡旋结构周围的湍流的包裹的、接近方位角的形式。这种方法可以控制给定旋涡大小和强度的外部湍流强度和长度尺度的初始值。在较宽的初始湍流强度范围内，考察了湍流对涡流对颗粒弥散的影响。对零轴向流和非零平均轴向流不稳定涡的算例进行了分析。外部湍流的状态是由大尺度涡核的耗散、伸展和涡度重定向以及剥离之间的平衡决定的。我们研究了初始湍动能峰值相差高达400倍的情况，并且对于所有的情况…
A study is performed using direct numerical simulation to examine the effect of turbulence on particle dispersion in a columnar vortex. A procedure is used to generate initial conditions in which turbulence external to the vortex has the wrapped, nearly azimuthal form characteristic of turbulence around a large-scale vortex structure. This approach enables control of the initial values of the external turbulence intensity and length scale for a given vortex size and strength. The effect of turbulence on dispersion of particles by the vortex flow is examined for a wide range of different values of the initial turbulence intensity. Cases both with zero mean axial flow and unstable vortices with nonzero mean axial flow are examined. The state of the external turbulence is determined by a balance between dissipation, stretching, and vorticity reorientation and stripping from the large-scale vortex core. We examine cases with peak initial turbulence kinetic energy differing by a ratio of up to 400, and for all...