The effects of rigid vegetation on the turbulence characteristics were experimentally studied in the interior water flume. An ADV was used to determine the three dimensional turbulent velocities in clear water flow wi...The effects of rigid vegetation on the turbulence characteristics were experimentally studied in the interior water flume. An ADV was used to determine the three dimensional turbulent velocities in clear water flow without vegetation, sediment-laden flow without vegetation, sediment-laden flow with submerged vegetation and sediment-laden flow with non-submerged vegetation. By experimental and theoretical analysis, the effects of rigid vegetation on the distribution of averaged velocities, turbulence intensities and Reynolds stress were summarized. In sediment-laden flow with submerged vegetation, the averaged stream wise velocities above the top of vegetation fit well with the log distribution low. The three-dimensional turbulence intensities increase from the bottom until they reach the maximum at the top of the vegetation. The method to calculate the shear velocity with the maximum of the Reynolds stress is recommended. In sediment-laden flow with non-submerged vegetation, the turbulence problems cannot be explained by theory of bed shear flow. The average velocities, turbulence intensities and Reynolds stress approximate uniformly distributed along vertical direction.展开更多
文摘The effects of rigid vegetation on the turbulence characteristics were experimentally studied in the interior water flume. An ADV was used to determine the three dimensional turbulent velocities in clear water flow without vegetation, sediment-laden flow without vegetation, sediment-laden flow with submerged vegetation and sediment-laden flow with non-submerged vegetation. By experimental and theoretical analysis, the effects of rigid vegetation on the distribution of averaged velocities, turbulence intensities and Reynolds stress were summarized. In sediment-laden flow with submerged vegetation, the averaged stream wise velocities above the top of vegetation fit well with the log distribution low. The three-dimensional turbulence intensities increase from the bottom until they reach the maximum at the top of the vegetation. The method to calculate the shear velocity with the maximum of the Reynolds stress is recommended. In sediment-laden flow with non-submerged vegetation, the turbulence problems cannot be explained by theory of bed shear flow. The average velocities, turbulence intensities and Reynolds stress approximate uniformly distributed along vertical direction.
