溢流坝反弧段的流速分布

Experimental Studies of Velocity Distributions in the Buckets of Spillway Dams

根据试验研究资料,对溢流坝反弧段的流速分布进行了探讨。指出反弧水流的流速分布除受重力作用影响外,还受离心力作用的影响。当反弧半径为80cm左右,重力和离心力作用的相对大小发生转变,大于该值重力作用为主,小于该值离心力作用明显。提出了反映重力及离心力对壁面势流速度影响的综合参数,该参数在反弧段近似为常数。还指出在反弧段边界层内流速指数律有较好的适应性,影响指数的主要参数是弧长、反弧半径、雷诺数和无因次参数,并提出了反弧段流速分布指数的计算式与图表。

Hydraulic measurements were made in the buckets of model spillway dams. The potential velocity distribution outside boundary layer on the buckets and the exponential law of velocity distribution inside boundary layer on the buckets were studied experimentally in detail. It is found that the velocity distributions are affected not only by gravity but also by centrifugal force, but the main effect is not same for the curvatures of buckets. A critical value about that is obtained. Some parameters, especially about the curvatures of the buckets, are suggested to show the effects on the velocity distributions.