1 - 水利水运工程学报.doc

基于水流粘滞性的模型沙选择 魏炳乾11，1，王非1，庞洁，1 （1，西安理工大学水利水电学院,陕西 西安 710048 2.杨凌职业技术学院，陕西，杨凌 712100） 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，若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,通过控制实验水温，根据不同温度下，水的粘滞系数不同，得到的颗粒粒径就会改变来优化模型选沙。同时在原温和变温两种条件下分别计算泥沙粒径的沉速并计算沉速比尺,结果说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，结果满足沉速相似也达到悬移相似要求。通过模型试验验证，表明模型沙选择满足要求，模型设计合理。因此利用水流粘滞性选择模型沙是对全沙模型沙的一种新的尝试，可供同类工程参考借鉴。 关键词：水流粘滞性;动床试验；模型沙；粒径；悬移相似 中图分类号：TV133.1 文献标识码：A Selection of model sand based on the flow viscosity WEI Bingqian, GONG Xiuxiu, YAN Pei, WANG Fei, PANG Jie, HU Hongsheng (1.College of Hydraulic and Hydropower, Xi’an University Of Technology, Xi’an 710048, China;2.Yangling Vocational Technical College,Yangling 712100, China) Abstract: In the study of sediment sand movable bed model test，model sand design is to the whole model text. Since the prototype sediment particle size is thinner, ignoring the temperature difference between the model sand and the prototype sand , the calculation of natural model sand partical size is too small ,and it is difficult to get. So we change the experimental temperature, while the temperature is different, the flow viscosity is different, the particle size will change which can select optimization model of sand under the condition of the suspension similarity.Under the condition of the original and variable temperatures, we calculate the sand settling velocity and scale, the results showed our selection about model sand particle size is reasonable. Coarse natural sand has been used to simulate fine sand in prototype, the results met the settling velocity and suspended?similarity requirements . According to the analysis of model experiment, the model sand design can meet the requirements，model design is reasonable. Getting use of flow viscosity is a new trial to select model sand , which can be a good reference in the similar project. Keywords: flow viscosity; movable-bed test; model sand; particle size; suspension similarity 1.前言 河工模型试验是在远较原