Direct numerical simulation of a 30R long turbulent pipe flow at Re τ = 3008

• DOI: 10.1063/1.4922612
• Publication Date: 2015-06-18T17:00:39Z
• Authors: Junsun Ahn; Jae Hwa Lee; Jin Lee; Ji-hoon Kang; Hyung Jin Sung
• Keywords: Kolmogorov microscales; Reynolds stress; Pipe flow

A direct numerical simulation of a turbulent pipe flow at high Reynolds number Reτ = 3008 over long axial domain length (30R) was performed. The streamwise mean velocity followed the power law in overlap region (y+ 90–300; y/R 0.03–0.1) based on indicator function. scale separation shear stresses into two components small- and large-scale motions (LSMs) revealed that LSMs outer played an important role constructing constant-stress layer velocity. In pre-multiplied energy spectra fluctuations, bimodal distribution observed both short wavelengths. kx−1 associated with attached eddies appeared λx/R 2–5 λx/y 18–160 y+ 90–300, where established same region. kz−1 also λz/R 0.3–0.6 3 150. Linear growth small-scale to induced numbers, resulting large population LSMs. This result supported origin very-large-scale pseudo-streamwise alignment stress, without