Author(s): Dan Wang, Feng Li, Zhi Jie Li, Wen Qi Li, Ke Jun Yang

Linked Author(s): Dan Wang

Keywords: Vegetation, density, velocity, adjustment length, wake region

Abstract:

The interaction between vegetation and water flow is very common in the actual channel. This experimental study described how vegetation community density and bed form influence the velocity, upstream adjustment length and wake region around a non-submerged patch of model vegetation. Instantaneous measurements of longitudinal velocity, lateral velocity and vertical velocity were measured by a Nortek Vectrino. Based on the test data, the trend of longitudinal distribution of depth average velocity does not depend on bed form and vegetation community density, even if the values of flow velocity in all cases are not exactly the same. Moreover, bed form and vegetation community density have effects on upstream adjustment length and steady wake length. For high flow blockage, upstream adjustment length is greater than that of the low, and the variation of steady wake length is contrary. The bed form has little effects on the upstream adjustment length. L0 is similar in packed, movable and feeding sediment cases. The presence of sediment leads to the decrease of steady wake length. By adding sediments to the flow upstream of the flume, we can find that the value of L1 becomes smaller. (2628, 62, 268)

DOI:

Year: 2017