E335 高レイノルズ数平行平板間乱流における微細渦のクラスター構造(E-33 乱流渦構造(3),一般講演)

概要

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To investigate a cluster structure of coherent fine scale eddies (CFSEs) in the logarithmic region, direct numerical simulations of turbulent channel flows were conducted for Re_τ=800 and 1270. The cluster structures of vortices are defined by the CFSEs and their axes. These structures involve streamwise velocity defect and relatively high dissipation rate of turbulent kinetic energy in the outer region, especially in the logarithmic region. Temporal development of the spatial distributions of the CFSEs reveals that the clusters of the CFSEs in the outer region are observed sequentially. The CFSEs in the large-scale motion (i.e. the cluster of vortices) have relatively strong swirling motions compared with those in the whole flow field. Therefore, the cluster of the CFSEs generates the high dissipation rate of turbulent kinetic energy and Reynolds shear stress in the logarithmic region.
日本流体力学会の論文
2004-08-09