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。
To explore the effect of flow and water salinity on the flocculation-settling of cohesive sediment in estuary and coastal region,we took sediment concentration and floc diameter as parameters,and used a self-made rotary cylinder and electrolyte added method to examine the flocculation-settling process under six flow intensities（0 s^-1,1.38s^-1,2.54 s^-1,4.67 s^-1,7.19 s^-1,13.2 s^-1,20.3 s^-1） and three electrolytes（NaCl,CaCl2,AlCl3）.The results showed that：1 The effect of flow on flocculation-settling of cohesive sediment is related to flow intensity.Low intensity flow improves the flocculation-settling at early stage and hinders it at the other stages,while high intensity flow always retards it because of the strong shear stress and turbulent mixing.2 The existence of electrolyte has a net expansionary effect on the action of low intensity flow and a contractile effect for high intensity flow.In the same concentration,when the cation valence of electrolyte becomes from ＋1 to ＋3,the influence of flow becomes greater,especially at stabilization period.
出处
《水科学进展》
EI
CAS
CSCD
北大核心
2017年第2期285-292,共8页
Advances in Water Science
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)~~
关键词
紊流
电解质
黏性泥沙
泥沙浓度
絮团粒径
turbulent flow
electrolyte
cohesive sediment
sediment concentration
floc diameter
