Bubble-type vortex breakdown of the swirling flow inside a closed cylindricalcontainer with a rotating upper endwall was experimentally investigated via LDV. 3D measurement ofthe steady bubble at H/R =1.5 was firstly ...Bubble-type vortex breakdown of the swirling flow inside a closed cylindricalcontainer with a rotating upper endwall was experimentally investigated via LDV. 3D measurement ofthe steady bubble at H/R =1.5 was firstly carried out with very fine grid arrangement. Flow detailsinside the bubble and its Re -dependent structure were made clear. Abrupt waves of the azimuthalvelocity component were always found to be between the bottom stationary endwall and the upstreamstagnation point, which might be the reason of bubble formation. Variation of bubble structure andbubble center with the increasing Re gives the explanation for the disappearance of the breakdownregion.展开更多
文摘Bubble-type vortex breakdown of the swirling flow inside a closed cylindricalcontainer with a rotating upper endwall was experimentally investigated via LDV. 3D measurement ofthe steady bubble at H/R =1.5 was firstly carried out with very fine grid arrangement. Flow detailsinside the bubble and its Re -dependent structure were made clear. Abrupt waves of the azimuthalvelocity component were always found to be between the bottom stationary endwall and the upstreamstagnation point, which might be the reason of bubble formation. Variation of bubble structure andbubble center with the increasing Re gives the explanation for the disappearance of the breakdownregion.
