Research The Flow Discribution And Turbulent Flow Characteristics Of Rigid Submerged Simulate Vegetation In Channel

To study the effect of vegetation on the river flow, to purify water quality, ecological protection, ecological restoration of rivers and lakes has important practical and scientific significance. This research adopts the simulate rigid vegetation as the experimental materials, the experimental channel discharge is 90L/s, round rods denisty is set to 5、108、202 s/m2, simulate vegetation height select 1.25cm,2.5cm, 3.75cm,5cm,6.25cm,7.5cm and 8.75cm. Flow velocity and water depth are measured on three longitudinal-sections and nine transverse-sections respectively with SonTek 3-D Acoustic Doppler Velocimeters and ABF2-2 two-dimensional water level measurement system, and analyze the relative turbulence intensity of important points. Study the effects of rigid vegetation to velocity distribution and relative turbulence intensity, the results show that:(1) For each vertical section, the water depth along the longitudinal flow increased with the increase of vegetation density, with the increase of height of vegetation, the greater the difference between each other with a higher density; the flow velocity decreases with the increase of density, and basic decrease with the increase of vegetation height; In vertical direction, flow velocity increased gradually from the bottom of the channel to the surface water, the velocity of vegetation area is lesser, the vegetation area and vegetation area velocity is larger;(2) For each vertical section, the relative turbulence intensity increased with the increase of density increase on the transverse, longitudinal and vertical;When vegetation density is small, with the increase of vegetation height, relative turbulence intensity changed little;In the area of vegetation, under different vegetation height, relative turbulence intensity is basic to the minimum.This article reveals rigid submerged simulate vegetation’s influence on the channel flow field distribution and turbulent flow characteristics.It provides a certain theoretical basis for the recent natural river ecological restoration and design.