Abstract: Based on the model of hooked groin,the flow characteristic,which is dcfferent from non- composite groin,is studicd,It showcs that flow pattern varies with the different combinations of hooked lengthes and booked angles aeeording to the submerged and non-submerged conditions.The tesults could be useful for the design of river and waterway regulation engineering.?

Key words: hooked length, hooked angle, groin, flow structure

摘要： 本文通过在试验水槽中模拟河道工程常采用的勾头丁坝这种组合坝型，着重研究了不同勾角和不同勾长组合时时而场产生的影响，分析了产生这种影响的内在机理．结果表明:(1)增加勾头后，不同程度地减弱了原了坝坝头水而分离产生的漩涡，减少了坝后能量损失．(2)同一匀长内不同勾角对坝头前后的流速分布将产生不同的影响．本研究成果对指导航道整治工程、护岸及滨江工程有一定的参考价值．

关键词: 丁坝, 勾长, 勾角, 水流结构, 压缩比