While turbulent mixing has been studied extensively in homogeneous turbulence, chemical engineering processes where mixing is important are anisotropic. In anisotropic turbulence, the interplay between convection and diffusion is critical. Flow in an infinite channel is utilized here with clouds of scalars released instantaneously at different distances from the wall and at Schmidt numbers between 0.7 and 2400. Qualitative and quantitative measures of mixing efficiency and intensity are defined and the dynamics of mixing are explored. It is found that molecular diffusivity can even hinder mixing in some instances, because it affects the development of the cloud of the released scalars from regions within the viscous wall layer. Another finding is that while one would expect mixing to occur mostly in the space between two points of release, considerable amount of mixing could take place outside of this region and closer to the wall. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2803–2815, 2018

中文翻译：

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各向异性湍流中的标量混合

尽管已经在均相湍流中对湍流混合进行了广泛的研究，但是在混合中很重要的化学工程过程却是各向异性的。在各向异性湍流中，对流和扩散之间的相互作用至关重要。这里利用无限通道中的流动，并在距壁的不同距离处以0.7和2400之间的施密特数即时释放的标量云。定义了混合效率和强度的定性和定量方法，并探讨了混合动力学。发现分子扩散率在某些情况下甚至会阻碍混合，因为它会影响从粘性壁层内区域释放的标量云的发展。另一个发现是，虽然人们期望混合主要发生在两个释放点之间的空间中，大量的混合会发生在该区域之外并更靠近墙壁。©2018美国化学工程师学会AIChE J，64：2803–2815，2018