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Determination of the Flow Velocity Resistance in Non- Submerged Woody Plants

A. A. Alshlem, Sundus Almontasir

Abstract


Vegetation on the bank of a river or stream has a major influence on resistance, velocity distribution,and turbulence force. The resistance to flow in open channels depends on different channel and flow parameters. Out of many factors, vegetation is the mainly important parameter in open channels. In this study have been five points to measure the velocity in the channel. The experimental work has been done by a rectangular channel made from Mild Steel, Aluminium, Alloy, Stainless Steel, and transparent clear acrylic 10 mm. and with a uniform cross-section built inside a metallic flume. The measurements were carried out under various hydraulic conditions in the flume. The stiff plants carefully were selected shaped to fit the natural plants found in nature in the non-submerged case. Several discharges Q were explored. Data were available for analysis from 15 test series versus velocity for un-submerged vegetation, Point velocities at grid points of the different cross-sections are
collected and the velocity contour of each cross-section is plotted using excel. The results expose that inside the cylindrical rods’ layer, the velocity profiles no longer follows the velocity of the flow of liquid logarithmic law profile reduces within the vegetated region of the channel. It is identified that the added external drag force applied by plants reduces the mean flow velocity surrounded by a vegetated section of the channel compared to the non-vegetated section. The effects of hydraulic flow characteristics of riparian vegetation were studied by taking vertical velocity measurements of the most irregular deflected shape of the vegetation. Within vegetation, the mean velocity decreases with the flow for which the vegetative roughness increases with decreasing velocity.


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References


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