圆拱形明渠阻力系数的试验研究

On Friction Factor of Flow in Smooth Open Channel

本文结合工程水力模型对两种底坡的有机玻璃明渠进行试验研究．试验表明，在水力 光滑区沿程阻力系数λ与雷诺数Ｒｅ可表为指数函数关系，明渠底坡对阻力系数λ的变化规律没 有影响，而在过渡粗糙区明渠底坡对其则有明显影响．其次根据实测资料数值分析表明，在水力 光滑区谢才系数Ｃ与水力半径Ｒ及糙率ｎ的关系，仍可表成Ｃ＝ Ｒｙ的指数函效形式，文中提出谢 才系数Ｃ的经验计算公式．

The paper deals mainly with a projeet hydraulic model testing on an open channel flow with smooth walls . The findings have indicated that the bot- ton slope of a channel does not have appreciable influence on the friction of flow in the hydraulic smooth region, as it does on the friction of flow in the hydrau- lic rough region. It has also shown that the relationship can be expressed in terms of an exponential function between the Chezy's resistance factor C, and the hyd- raulic radius R, as well as the Manning's Coeffieient of Roughness n for an open channel flow in hydraulic smooth region. A semi -empirical formula has been given too.