Incipient sediment motion based on turbulent fluctuations
Incipient sediment motion based on turbulent fluctuations作者机构:Department of Civil & Structural EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia School of Civil and Environmental EngineeringCollege of EngineeringNanyang Technical University
出 版 物:《International Journal of Sediment Research》 (国际泥沙研究(英文版))
年 卷 期:2020年第35卷第2期
页 面:125-133页
核心收录:
学科分类:0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0708[理学-地球物理学] 0818[工学-地质资源与地质工程] 0903[农学-农业资源与环境] 081502[工学-水力学及河流动力学] 0815[工学-水利工程] 0816[工学-测绘科学与技术]
主 题:Incipient sediment motion Root-mean-square fluid velocity Grid-turbulence Quadrant analysis Turbulent fluctuations
摘 要:The current study modifies the representation of the Shields parameter using turbulent strength,*** root-mean-square(rms) fluid *** were done under a steady,uniform flow using eight sediment sizes with particle Reynolds numbers(Rep) ranging between 1.0(fine sediment) and 183.4(coarse sediment).Utilising the peak rms horizontal(u) values,the critical Shields parameter,θ,was calculated and a trend similar to the well-established Shields curve was *** analysis was extended to the Shields curve obtained based on the critical shear velocity,Reynolds shear stress,and data extracted fro m the oscillating grid-turbulence *** show that turbulent fluctuations are crucial for the incipient sediment motion and are essentially better predictors than the commonly used critical shear velocity.A quadrant analysis to identify the role of turbulent bursting events in incipient sediment motion also was done where sweeps and ejections are dominant for finer and coarser sediment sizes,respectively.