挟沙水流综合糙率系数的研究

Study on the roughness in sediment-laden flows

在现有研究成果的基础上,通过分析大量天然河道实测资料和他人的水槽试验资料,发现在挟沙水流中,综合糙率系数与水深、流量的相关性较差;与含沙量的相关性较好,并且糙率系数随含沙量的增加先减小后增大;在一定佛氏数条件下,糙率系数与佛氏数的相关性最好,且随佛氏数的增加而减小,可以根据佛氏数来计算糙率系数,但在较大佛氏数后,二者关系出现"向上翘"现象。

Based on the analyses of the field and flume experimental data, the integrated roughness of sedimentladen flows has been studied. It indicates that the roughness has a poor relationship with the flow discharge and depth, but a good relationship with sediment concentration. Besides, the roughness increases first and then decreases with the increase of sediment concentration. The study also shows that for a certain range of Froude number （Fr）, the roughness has a very good relationship with the Fr and therefore the roughness can be calculated if Fr is known.