Publication de 12 numéros par an
ISSN Imprimer: 1091-028X
ISSN En ligne: 1934-0508
Indexed in
PIV MEASUREMENTS OVER A PERMEABLE AND AN IMPERMEABLE BED
RÉSUMÉ
In this study, the characteristics of turbulent flow in an open channel with permeable (vegetation) and impermeable bed were studied experimentally using two-dimensional (2D) particle image velocimetry (PIV). The experiments were conducted for both impermeable and permeable beds in a channel 6.5 m in length, 7.5 cm in width, and 25 cm in height. For the simulation of the permeable bed two types of grass-like vegetation with different heights (2 and 6 cm) but with the same porosity (ε = 0.80) were used. These conditions are typical of flows encountered in sediment transport problems. Hydraulic characteristics such as distribution of velocities, turbulent intensities, and Reynolds stress are investigated at a fine resolution using the PIV. Velocity is measured above the vegetation for the permeable bed and above the impermeable bed for the same different total heights. Results show that velocity over the vegetation region is a function of the vegetation height and the total flow depth; velocity decreases as the vegetation height increases. In addition, we show that velocities above the vegetation region are much lower than velocities above an impermeable bed. This is due to the drag resistance of the vegetation. This result shows that 50% of the vegetation behaves like an impermeable bed. The measurements of mean velocity indicate the effect of the permeable bed on the flow characteristics. Also, the presence of the vegetation influences significantly the variation of longitudinal turbulent intensity u'/U* and vertical turbulent intensity v'/U*.
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Keramaris E., Effects of inclined impermeable bed on the turbulent characteristics of the flow using particle image velocimetry, Journal of Turbulence, 16, 6, 2015. Crossref
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Keramaris E., Pechlivanidis G., Effects of different porous beds on turbulent characteristics in an open channel above the porous bed, Flow Measurement and Instrumentation, 54, 2017. Crossref
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Pechlivanidis George, Savvidis Yiannis, Keramaris Evangelos, Koutitas Christopher, Investigation of the Optimum Connection of a Fish Pond with the Adjacent Main Riverine Flow, Procedia Engineering, 162, 2016. Crossref
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Savvidis Yiannis, Keramaris Evangelos, Pechlivanidis George, Koutitas Christopher, Optimum design of the entrance of a fishpond laterally to the main stream of an open channel, Environmental Science and Pollution Research, 24, 25, 2017. Crossref
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Jia Yu-Peng , Wang Jing-Fu , Zheng Kun-Can , Zhang Bing , Pan Gang , Gong Zhi-Jun , Wu Wen-Fei , Measurement of single phase flow in porous media using PIV technique, Acta Physica Sinica, 65, 10, 2016. Crossref