Abstract: The?bed?shear?stress?in?bend?flow?is?the?direct?motivation?for?sediment?initiation,?which?is?an?important?issue?for?hydraulic?engineers?to?concern?about.?A?generalized?curved?conduit?flow?experiment?is?employed?to?systematically?study?the?flow?characteristics?and?the?kinematical?law.?The?3D?flow?velocity?parameters?are?measured?by?adopting?the?ADV?（?Acoustic?Doppler?Velocimeter）.?Based?on?the?proposed?calculation?methods?of?water?surface?transverse?gradient,?longitudinal?gradient?in?curved?flow?and?depth?averaged?longitudinal?velocity?distribution,?a?set?of?formulas?to?compute?the?bed?shear?stress?in?bend?flow?are?theoretically?established.?Then?each?different?parameter?affecting?the?bed?shear?tress?is?calculated?independently?and?in?detail?to?obtain?the?distribution?pattern?of?the?bed?shear?stress.?Results?show?that?the?research?achievements?are?in?accordance?with?the?predecessors＇?findings?basically.?However,?it?is?relatively?more?systematical?and?ideal,?which?can?be?taken?as?the?basis?to?explore?the?hydraulic?characteristics?profoundly.

Key words: hydraulics , curved conduit flow , bed shear stress

摘要： 弯道床面切应力是弯道泥沙起动的直接动力,运用弯道水流概化模型试验,利用先进的ADV进行了三维流 速数据的采集。弯道水面横比降与纵比降的沿程分布公式以及弯道水流纵向垂线平均流速计算方法,从理论上进 一步推导得到了弯道床面切应力分布的公式。通过计算,给出了不同参数对弯道床面切应力分布的影响。研究表 明,计算床面切应力的分布不仅与前人研究成果基本一致,而且更加完善和系统化,为深入探讨弯道水流特性奠定 了基础。

关键词: 水力学, 弯道水流, 床面切应力