水流和电解质对黏性泥沙絮凝沉降影响试验

发布时间：2018-10-21 14:26

【摘要】：为探索河口海岸地区水流和盐度共同作用对黏性泥沙絮凝沉降的影响,以泥沙浓度和絮团粒径为参数,采用自制的同轴旋转双筒产生运动水流和外加电解质的方法,研究6个水流强度(0 s~(-1)、1.38 s~(-1)、2.54 s~(-1)、4.67 s~(-1)、7.19 s~(-1)、13.2 s~(-1)和20.3 s~(-1))和3种电解质(NaCl、CaCl_2、AlCl_3)作用下的黏性泥沙絮凝沉降过程。试验结果表明:1水流对黏性泥沙絮凝沉降的影响与其强度相关。低强度水流(水流强度小于4.67 s~(-1))表现为初期促进、中后期阻碍的规律;高强度水流则由于强水流剪切力和自上而下的紊动掺混作用始终起阻碍作用。2电解质的存在将分别增强和减弱高、低强度水流所起作用;相同浓度下,当阳离子化合价从+1价变成+3价时,水流的影响作用更明显,尤其体现在稳定段。
[Abstract]:In order to explore the effect of the interaction of water flow and salinity on the flocculation settlement of viscous sediment in estuarine and coastal areas, the self-made coaxial rotating bimetal method was used to produce moving water and applied electrolytes, with the sediment concentration and the particle size of flocs as parameters. The flocculation processes of viscous sediment under the action of six flow intensities (0 s ~ (-1), 1.38 s ~ (-1), 2.54 s ~ (-1), 4.67 s ~ (-1), 7.19 s ~ (-1), 13.2s ~ (-1), 20.3s ~ (-1) and three kinds of electrolytes (NaCl,CaCl_2,AlCl_3) were studied. The results show that: 1 the influence of water flow on the flocculation settlement of viscous sediment is related to its strength. Low intensity flow (flow intensity less than 4.67 s ~ (-1) shows the law of initial promotion and middle and late stage hindrance; High intensity water flow is always hindered by shear force and top-down turbulence mixing. 2 the presence of electrolyte will strengthen and weaken the effect of high and low intensity water flow respectively; at the same concentration, When the cation valence changes from 1 valence to 3 valence, the effect of water flow is more obvious, especially in the stable section.
【作者单位】：长江科学院河流研究所;清华大学水沙科学与水利水电工程国家重点实验室;Hydraulics
【基金】：国家自然科学基金资助项目(51609012) 长江科学院中央级公益性科研院所基本科研业务费资助项目(CKSF2016010/HL)~~
【分类号】：TV149

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