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INTERACTION BETWEEN TURBULENT DYNAMICAL PROCESSES AND STATISTICS IN DEFORMED AIR-LIQUID INTERFACES, VIA DNS

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

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

Аннотация

The present study investigates the effects of a surface deformation on near free-surface turbulent structures, by means of direct numerical simulation (DNS). Target flow fields are two different types of air-liquid interface turbulent shear flows. One flow filed is a wind-driven turbulent flow at maximum wind speed of 2.2m/s. The other one is an air-liquid counter current flow induced by a high-speed liquid film at Froude number of 1.8 based on the bulk mean velocity and the wave velocity of a long wave. In the wind-driven flow, turbulent intensity distributions and theirs redistributions in the vicinity air-liquid interfaces are strongly influenced by the wind-wave shapes. On the other hands, vertical turbulent intensity in the open-channel flow has the peak value on the free-surface and a vertical confinement effect in a low-Fr flow is no longer present in this high-Fr flow. Beneath the airliquid interface, turbulence redistribution form vertical component to streamwise one is dominant in both cases.