手机知网 App
24小时专家级知识服务
打 开
数学
AN EXPERIMENTAL STUDY ON TURBULENT COHERENT STRUCTURES NEAR A SHEARED AIR-WATER INTERFACE
<正> The turbulence structures near a sheared air-water interface wereexperimentally investigated with the hydrogen bubble visualization technique. Sur-face shear was imposed by an airflow over the water flow which was kept free fromsurface waves. Results show that the wind shear has the main influence on coher-ent structures under air-water interfaces. Low- and high- speed streaks form in theregion close to the interface as a result of the imposed shear stress. When a certainairflow velocity is reached, "turbulent spots" appear randomly at low-speed streakswith some characteristics of hairpin vortices. At even higher shear rates, the flownear the interface is dominated primarily by intermittent bursting events. The coher-ent structures observed near sheared air-water interfaces show qualitative similaritieswith those occurring in near-wall turbulence. However, a few distinctive phenomenawere also observed, including the fluctuating thickness of the instantaneous boundarylayer and vertical vortices in bursting processes, which appear to be associated withthe characteristics of air-water interfaces.
3 18
手机阅读本文
下载APP 手机查看本文
Acta Mechanica Sinica
1999年04期
相似文献
图书推荐
相关工具书

搜 索