Experimental Study On Flow Structure Of Open-channel Flow And Around Particle Under The Influence Of Injection

This paper presents the preliminary understanding of the basic law of the impact of injection on open channel flow and how it affects flow structures around the particle through the experiment on injection effects on structural features of open channel and around particle.The results can enrich the mechanism knowledge of the seepage effect on open channel flow and reveal the internal mechanism of effect of seepage on incipient sediment motion.The results can also provide hydrodynamic theoretical basis for erosion and deposition problem caused by seepage and a theoretical reference for future practical engineering applications of river regulation and beach erosion.This paper investigates the flow characteristics in seepage zone by using Vectrino Profiler.Reynolds-stress method and log-law method were used to estimate friction velocity u*,which prove to be reliable methods to estimate friction velocity by measuring data.The results on the structure of open channel flow show that injection causes change in the velocity distribution,the rms values of velocity fluctuations,the shear stress and the seepage zone.The velocity distribution subjected to injection can be described by the modified log-law,and the roughness is affected by injection.Comparing the data obtained by Vectrino Profiler with that of PIV,the results show that the measured data match well with each other.This study also examines effect of injection on structural features around particle by using Particle Image Velocimetry.The results on the structure around particle show that injection can change the velocity distribution,the rms of velocity fluctuations and the vorticity.From micro-level,the results reveal the impact of injection on incipient sediment motion.