| 张法星,许唯临,朱雅琴.明渠自掺气水流气泡形成过程的试验研究[J].水利学报,2010,41(3): |
| 明渠自掺气水流气泡形成过程的试验研究 |
| Experimental study on formation of air bubbles in self- aerated open channel flows |
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| DOI： |
| 中文关键词: 明渠 自掺气 掺气机理 自由面 气泡 |
| 英文关键词: open channel flows self- aeration mechanism of air bubble entrainment free surface air bubbles |
| 基金项目: |
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| 中文摘要: |
| 采用高速摄像技术对陡槽内自掺气水流进行了观测，拍摄到了掺气起始区气泡在水流内部形成的完整过程，对气泡形成的过程进行了概化分析水面附近涡体运动产生的脉动压强和水面相互作用，导致水面发生上凸下凹的变形当这种变形达到一定程度后，受顺水流向或横向脉动压力 横向切应力的作用，深入水体凹坑的边壁在某一部位闭合下部包裹空气形成气泡而发生自掺气随着紊动强度进一步增大，水面变形加剧，表现为高高跃出水面的柱状突起和水滴这些水柱的倾倒、聚并也会造成空气进入水中形成气泡明渠水流自掺气是水体内部紊动与水面相互作用的结果。 |
| 英文摘要: |
| The high speed video camera was used to visualize the self- aeration process taken place at
the high speed flowing water surface. The pictures show how air bubbles are formed in the developing zone of self- aerated water flow. The interaction of pressure fluctuation caused by eddies and free water surface makes the strong deformation of surface. Once the deformation reaches a specific limit，the air will be captured into the water flow and forms the air bubble，which implies the beginning of self- aeration. When the turbulence of flow develops sufficient energetically，the
water surface breaks and creates water drops，bubbles and fully mixed two- phase flows. This means
that the turbulence at free surface results in the self- aeration of open channel flows. |
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