Burst–interface interactions in free surface turbulent flows
Burst–interface interactions in free surface turbulent flows
复制标题
DOI：
10.1063/1.869457
复制
发表时间：
1997-11
影响因子：
4.6
通讯作者：
M. Rashidi
中科院分区：
文献类型：
--
作者：
M. Rashidi
利用氧泡可视化和图像处理技术研究了湍流通道流动中爆发事件（即喷出和流入）与自由表面的相互作用。实验表明，流动主要是壁面喷射的产生、展向“上升涡”的形成以及这些结构与自由表面的相互作用。展向上升涡在壁面附近演化，到达自由表面，形成表面斑块，以展向“下摆涡”的形式滚回，并混合到整体流动中。此外，有证据表明马蹄形和曲棍球杆型涡与爆炸事件有关。地表特征的测量表明，喷出-流入事件与自由表面的变形和近地表涡度场和速度场的重新分布有关。可以看出，当上升涡到达自由表面时，表面经历一个上升或上升，而表面下降……
Interactions of bursting events (i.e., ejections and inflows) with the free surface in turbulent channel flows have been studied using oxygen bubble visualization and image processing techniques. Experiments indicate that the flow is dominated by the generation of wall ejections, formation of spanwise “upsurging vortices”, and interaction of such structures with the free surface. The spanwise upsurging vortices are seen to evolve near the wall, reach the free surface, form surface patches, roll back in form of spanwise “downswinging vortices”, and mix into the bulk flow. Furthermore, there are evidence of horseshoe and hockeystick type vortices in relation to the bursting events. Measurements of surface characteristics show that the ejection–inflow events are associated with deformation of the free surface and a redistribution of near surface vorticity and velocity fields. It is seen that as upsurging vortices reach the free surface, the surface goes through an elevation or a rise, whereas the surface fal...