| 摘要: |
| 对于研究泥沙问题的全沙动床模型试验，模型沙的设计是整个模型试验的关键。当原型泥沙粒径过小,不考虑模型与原型的温度差异时，按比尺计算得到的天然模型沙粒径太小，通常不易获得。因此在满足悬移相似条件下,通过控制试验水温，根据不同温度及不同水黏滞系数ν，得到合理的颗粒粒径从而优化模型选沙。在原温和变温两种条件下分别计算所选泥沙的沉速和沉速比尺，表明改变温度所选的模型沙粒径是合理的，用较大粒径天然沙模拟原型较细沙，既满足沉速相似也满足悬移相似要求。试验验证结果表明模型沙选择满足设计要求，模型设计合理。 |
| 关键词: 水流黏滞性 动床试验 模型沙 粒径 悬移相似 |
| DOI： |
| 分类号:TV142 |
| 基金项目:国家自然科学基金资助项目(2011CB403305)；陕西水利科技计划资助项目（2014skj-14）；陕西省教育厅科学研究计划项目(11JK0739) |
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| Model sand selection based on water flow viscosity |
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WEI Bing-qian1, GONG Xiu-xiu1, YAN Pei1, WANG Fei1, PANG Jie2, HU Hong-sheng1
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1.College of Hydraulic and Hydropower, Xi’an University of Technology, Xi’an;2.Yangling Vocational & Technical College, Yangling
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| Abstract: |
| For the studies of the total-load movable-bed model tests, the design of the model sand has become a key to the whole model testing. As the prototype sediment particle size is much small, ignoring the temperature differences between the model sand and the prototype sand, it is difficult to get the suitable natural model sand if the particle size of the natural sand calculated by the model scales is too small. So by controlling the flow temperature for the model experiments, under the conditions of different temperatures and different water flow viscosities, the reasonable sediment particle size can be got, so as to select optimized model sand in conditions satisfying suspension similarity. The sediment settling velocities and sediment settling scales have been simulated under the conditions of original and variable temperatures. And the model testing analysis results show that the choice of the model sand particle size in variable temperature conditions is available, and that the natural coarse sand used for simulation of the prototype finer sand not only meets the similarity requirements of the settling velocities, but the suspension similarity as well. The results of model testing validation indicate that the model sand selection has met the requirements of design and that the model design is reasonable. |
| Key words: flow viscosity movable-bed model tests model sand particle size suspension similarity |
