Flow-Depth Velocity Distribution Equationsfor Open Channel Flows

• Main Authors: Jui-Yen Chen, 陳睿彥
• Other Authors: Chyan-Deng Jan
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/49242144806671080582

碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 91 === The log-low flow-depth velocity distribution equations for open channel flow and the Coles’ wake-flow function were reviewed wake-strength coefficient in the wake function at various flow conditions were compared. The result reveals that the values of are presented by previous investigators between -0.27 and 0.65. It is also found that Cloes’s revised wake-flow function can not well describe the velocity distributions for some open channel flows which are influenced by the pressure gradient and the side-wall-effects. We propose a method to overcome the problem. The velocity distribution is divided into upper region and lower region at the basis on the depth where the maximum velocity. When the two coefficients are the same which to be equal to the Cloes revised wake-flow function. Comparison of the proposed double-layer velocity distribution with measured data by Cloemen(1981) and Kirkgoz and Ardiclikglu(1997). The results show that the present proposed method can well describe the velocity distributions, with between 0.9 and 1.6 and between -0.02 and 0.69. Besides, the modified functions for the power-low equation are also investigated in the present study. A modified function F(y/ )= is proposed for the power-low velocity distribution, and compared with the measured data. It shows that the revised power-low equation can well describe the velocity distribution. Based on Coleman’s data , and the velocity correction is between 0.15 and 0.28, and proportional with the vertically averaged volumetric sediment concentration.