有植被的河道水流紊动特性模型试验研究

Model test for turbulence of flow in vegetated channel

通过物理模型试验,研究了有植被的河道水流紊动特性.试验结果表明,在复式断面河道滩地种植柔性植被后,滩地糙率增大,水流紊动更为剧烈,河道水流紊动强度峰值由原先的滩槽交界区转移到滩地区.滩地的水流紊动强度沿程递减;滩槽交界区的水流紊动强度沿程不断增大;主槽的水流紊动强度主要与床面糙率有关,滩地植被影响了滩地水流的归槽时间,使主槽水流流速沿程增大.

The turbulent characteristics of flow in vegetated channels are studied in physical model tests. Test results show that the roughness of floodplain and turbulence of flow increase after flexible vegetation is planted in the floodplain of the waterway with a compound section, and that turbulence intensity peak is transferred to the floodplain from the intersection between the floodplain and the main channel. Turbulence intensity of flow in the floodplain decreases gradually along the river while that in the intersection region between the floodplain and the main channel increases. Turbulence intensity in the main channel is associated with the roughness of bed surface. Vegetations in the floodplain affect the time coming into the main channel of the floodplain flow and arouse the increase of flow velocity in the main channel along the river.