An experimental study of the molecular mixing process in an axisymmetric laminar vortex ring
An experimental study of the molecular mixing process in an axisymmetric laminar vortex ring
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轴对称层流涡环内分子混合过程的实验研究
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
Kenneth A. Buch
中科院分区：
文献类型：
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作者：
Kenneth B. Southerland;J. Porter;W. Dahm;Kenneth A. Buch
本文给出了轴对称层流涡环中动态被动守恒标量分子混合的实验研究结果。这些实验是基于环的直径平面中标量场的高分辨率激光诱导荧光成像测量，从中可以直接检查分子混合速率场的演化。特别是，在环演化的三个特征阶段，即（i）环生成阶段，（ii）环夹断阶段和（iii）环的渐近阶段，混合过程的结构和动力学都得到了解决。结果表明，分层的混合过程中，扩散抵消项（）：（）起着重要的作用，在设置实现的整体混合速率。标量场的测量也被用来提取有关环中的底层速度场的详细信息。
Results are presented from an experimental study of the molecular mixing of a dynamically passive conserved scalar quantity in an axisymmetric laminar vortex ring. The experiments are based on highly resolved laser‐induced fluorescence imaging measurements of the scalar field ζ(x,t) in the diametral plane of the ring, from which the evolution of the molecular mixing rate field ∇ζ⋅∇ζ(x,t) can be directly examined. In particular, the structure and dynamics of the mixing process are addressed during the three characteristic stages in the ring evolution, namely, (i) the ring generation stage, (ii) the ring pinch‐off stage, and (iii) the asymptotic stage of the ring. Results show a layering of the mixing process in which the diffusional cancellation term ∇(∇ζ):∇(∇ζ) plays a major role in setting the overall mixing rate achieved. The scalar field measurements are also used to extract detailed information about the underlying velocity field in the ring.