Yüksek Reynolds Sayılı Türbülanslı Kanal Akışının Doğrudan Sayısal Simülasyonu

Özet (abstract)

A direct numerical simulation of incompressible channel flow at a friction Reynolds number ( $\mathit{Re}_{{\it\tau}}$ ) of 5186 has been performed, and the flow exhibits a number of the characteristics of high-Reynolds-number wall-bounded turbulent flows. For example, a region where the mean velocity has a logarithmic variation is observed, with von Kármán constant ${\it\kappa}=0.384\pm 0.004$ . There is also a logarithmic dependence of the variance of the spanwise velocity component, though not the streamwise component. A distinct separation of scales exists between the large outer-layer structures and small inner-layer structures. At intermediate distances from the wall, the one-dimensional spectrum of the streamwise velocity fluctuation in both the streamwise and spanwise directions exhibits $k^{-1}$ dependence over a short range in wavenumber $(k)$ . Further, consistent with previous experimental observations, when these spectra are multiplied by $k$ (premultiplied spectra), they have a bimodal structure with local peaks located at wavenumbers on either side of the $k^{-1}$ range.

Yazarların özeti; kaynağından alınmıştır. Journal of Fluid Mechanics, 2015 · DOI ↗