【摘要】 河宽渐变是天然河道的普遍形态特征。基于室内概化试验,采用声学多普勒流速仪(ADV)测试分析了宽窄相间河道渐扩渐缩局部区域水流运动特性。试验表明:河宽变化影响着水流运动特征,随着河道渐扩与渐缩的变化,水位呈现逐渐增加与降低,渐扩区域时均流速、断面环流中上部流速逐渐减少,而渐缩区域呈现相反的趋势。渐扩与渐缩断面,断面环流呈现不同的演化趋势。此外,宽窄相间不同水深区域均出现水流分离区,渐缩区域受壅水影响,流速分布趋于均匀化。更多还原

【Abstract】 The wide gradual channel is a common form of natural rivers. The flow structure was measured in the physical model with wide gradual channel by means of acoustic Doppler velocimeter. The results showed that the flow presents different evolutions between the local diverging sections and converging sections. The scales of the streamwise velocity and the secondary flow of the upper layer decrease in diverging sections,however,the later shows the inverse variations in converging sections. In addition,the flow separation occurs in the whole lotus root shape channel. These flow characteristics often affect the sediment movement and channel processes.更多还原