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15 mins
Characteristics of overlap region in high-Reynolds number turbulent channel flow
Yoshinobu Yamamoto, Yoshiyuki Tsuji
Session: Wall-bounded flows 3
Session starts: Wednesday 26 August, 10:30
Presentation starts: 11:30
Room: Room I

Yoshinobu Yamamoto (Univ. of Yamanashi)
Yoshiyuki Tsuji (Nagoya Univ.)

Direct numerical simulation of the fully developed turbulent channel flows have been carried out at the Reynolds number based on the friction velocity and the channel half width, 2000, 4000 and 8000. A hybrid 10th order accurate finite difference scheme in the stream and spanwise directions, and a second-order scheme in the wall-normal direction is adapted as the spatial discretization method. We observed the plateau profiles in the indicator function corresponded to the von Karman constant. Furthermore, second peak of streamwise pre-multiplied spectra were appeared in the same wall normal height, 300 < y+ < 600, in case of Re = 4000. Nevertheless, the effects of the lager than the channel half height scale on the streamwise turbulent intensity are fixed contributions without dependence on Reynolds number. These results suggested that the new streamwise vortexes are formed between buffer layer and outer layer with increasing of Reynolds number.