WALL-NORMAL VELOCITY, TURBULENT STRUCTURES AND SEDIMENT TRANSPORT
This study investigates the influence of wall-normal velocity on turbulence structures,sediment transport and fluvial revolution starting from the definition of shear stress on an interface.Existing theories in turbulence and sediment transport are in principle applicable for describing fluvial evolutions in some cases, but it is widely observed that in river flows the measured velocity, Reynolds shear stress, turbulence intensities and sediment concentration distributions often deviate significantly from the predicted values. This research work attempts to clarify the mechanism for these deviations,and the results show that neglecting momentum flux by non-zero wall-normal velocity results in the invalidity of existing theorems. The wall-normal velocity could be induced by secondary currents and accelerating/decelerating motions, the relation has been established. It is found that, after introduction of wall-normal velocity, the existing theories could be extended to river flows, and some observed odd phenomena become understandable. The derived equations are in good agreement with experimental data available in the literature.
turbulence intensity Reynolds shear stress mizing length wall-normal velocity secondary currents
Shuqing Yang
School of Civil, Mining and Environmental Engineering, Univ.of Wollongong, Asustralia
国际会议
第16届亚太地区国际水利学大会暨第3届水工水力学国际研讨会(16th IAHR-APD Congress and 3rd Symoposium of IAHR-ISHS)
南京
英文
907-912
2008-10-20（万方平台首次上网日期，不代表论文的发表时间）