Inscrição na biblioteca: Guest
TSFP DL Home Arquivos Comitê executivo

RELATIONSHIPS BETWEEN COHERENT STRUCTURE AND TURBULENT STATISTICS STRUCTURE IN WIND-DRIVEN TURBULENT FLOW, VIA DNS

Tomoaki Kunugi
Department of Nuclear Engineering, Kyoto University, Kyoto Daigaku-Katsura, Nishikyo-ku, Kyoto, Japan

Yoshinobu Yamamoto
Department of Nuclear Engineering, Kyoto University, Yoshida Sakyo-ku, Kyoto 606-8501,Japan

Shin-ichi Satake
Department of Applied Electronics, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 Japan

Akimi Serizawa
Department of Nuclear Engineering, Kyoto University, Yoshida-Honmachi, Kyoto 606-8501, Japan

Resumo

In this study, direct numerical solution procedure (MARS method) for a coupled gas-liquid flow is employed to investigate the relationships between the coherent structure and turbulent statistics in wind-driven turbulent flow. The Reynolds number is about 3540 based on the gas layer height and the free stream velocity. As the results, near free-surface, like a viscous sublayer structure cannot be observed, turbulent was constrained and gas flow was laminarized compared with the smooth wall boundary flow. But, vertical fluctuation component is lager than that of no-deformation free-surface flow and turbulent intensities show the isotropy tendency. In the present condition, turbulent structure near free-surface is like an incompletely or completely rough bed wall structure. In the concentration fileds, near free-surface in the gas side, alternating high and low consentlation streaks existed as well as velocity fileds and high concentration regions at the free-surface are observed in the regions where high pressure existed and free-surfaces were deformed toward the downward. These mean that the effects of the surface deformation are dominant the mass transfer accross the free-surface in capillary wave of the wind-driven turbulent flow.