| 王浩,范洁铃,钟强,陈槐,陈铭,彭国平.基于高速摄像技术的推移质床面沙条带结构试验研究[J].水利学报,2020,51(8):987-996 |
| 基于高速摄像技术的推移质床面沙条带结构试验研究 |
| Experimental study of bed load streaky structure based on high speed video measurement |
| 投稿时间：2020-02-29 |
| DOI：10.13243/j.cnki.slxb.20200116 |
| 中文关键词: 推移质运动 图像处理 条带结构 流向涡 床面地形 |
| 英文关键词: bed load image processing streaky structure streamwise vortex bed morphology |
| 基金项目:国家自然科学基金项目（51709047） |
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| 摘要点击次数: 2928 |
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| 中文摘要: |
| 本文开展推移质平衡输沙试验，基于图像处理、PTV方法和卡尔曼滤波算法，分析床面推移质泥沙颗粒运动规律。在此基础上使用SFM方法重构床面三维地形并与颗粒运动对比，以研究推移质运动与紊流相干结构相互作用机理。结果表明：（1）通过本文方法，可从颗粒尺度较好识别推移质运动轨迹，为推移质运动机理研究提供新思路。（2）一定水流强度条件下（Θ=0.048，0.06），推移质运动强度在床面沿横向方向存在高低间隔的带状结构，水槽中间区域明显，至水槽两侧结构逐渐消失。（3）床面形成交替间隔的沙脊和沙垄结构时，沙垄区域推移质运动强度大，沙脊区域推移质运动强度小。（4）流向涡模型能够很好地解释推移质运动强度及床面沙脊沙垄结构沿横向间隔分布的特征。推移质床面沙条带结构和大尺度流向涡结构相互耦合，形成稳定的时间平均尺度床面结构。 |
| 英文摘要: |
| Flume experiments were conducted to study the mechanics of equilibrium sediment transportation based on image processing technique, PTV method and Kalman Filters algorithm. On this basis, the three-dimensional bed surface topography reconstructed by SFM was compared with particle movement to study the interaction mechanism between sediment particle movement and turbulent coherent structure. The results show that:(1) The method in this paper can be applied to recognize the sediment particle trajectories in the particle scale,which provides a new idea for studying mechanics of bed-load transport. (2) Under the certain flow conditions(Θ=0.048,0.06),sediment movement intensities has a high and low alternating streaky structure along the spanwise direction,reaching its maximum at the center and decreasing gradually toward the side wall. (3) When the alternating ridges and troughs structure formed on the bed surface, the bed load motion intensity is high in the ridge region and low in the trough region. (4) The streamwise vortices model can well explain the characteristics of sediment movement intensity and sediment streaks alternating in the spanwise direction. The time-averaged bed structure is formed by the coupling interaction of sediment streaky structure and super-streamwise vortices. |
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