粘性泥沙分层运动中流速垂线分布特征试验

Experiment on vertical distribution characteristics of flow velocity in cohesive sediment lamination movement

在前人研究的基础上,通过室内水槽试验,进一步研究了在流量、含沙量及水质影响下,分层运动中流速垂线的总体分布形态、分布规律、峰值及位置,以及清浑水界面位置等特征.结果表明,分层运动时,流速的垂线分布呈横向抛物线形;分层流区的近底区内流速遵循指数型分布规律,交混区和清水区内流速遵循修正后的高斯正常误差定律;分层流的峰速值越大,其位置越靠近河床;水流强度增加时,清浑水分界面位置向水面靠近,泥沙浓度增大时,界面位置向床面移动,而不同水质条件下的界面位置不同.

Based on the previous achievements and by means of indoor flume experiment,the effects of flow discharge,sediment concentration and water quality on the vertical distribution characteristics of flow velocity in cohesive sediment lamination movement are further investigated.The results indicate that,when lamination movement occurs,the flow velocity profile presents as a transverse parabolic curve.In the near bottom region,the flow velocity follows exponential-type distributuion law,and in the transition region and clear water region,it follows modified Gaussian normal error law.The greater the peak value of flow velocity is,the closer its location gets to the bottom.When flow intensity becomes greater,the interface between clear and turbid water will get close to the water surface;comparing with its getting close to the bottom when sediment concentration becomes higher.And in different water quality conditions,the location of the interface varies.