论文部分内容阅读
对不同流态及流区明渠水流阻力系数的计算公式进行总结。考虑到指数型表达式在进行数学推导及应用时较其他形式更为方便,基于该形式并结合尼古拉兹管流试验资料,推导了各流态及流区明渠阻力系数的具体表达式且得到实测资料的验证。推导过程中,借助明渠当量直径实现管流与明渠阻力系数的相互转换,并依据各流区水流特征的不同,对Christoffersen和Jonson提出的糙率高度公式作了不同简化。将所得阻力系数公式应用于河流及海洋近岸水流挟沙力的计算中,结果表明实测值与计算值相吻合,且所有流区阻力系数表达式形式的统一有利于水流挟沙力计算的简便。
The formulas for calculating the resistance coefficient of water flow in different flow regimes and open channel are summarized. Considering that exponential expressions are more convenient than other forms in mathematical derivation and application, based on this form and combined with Nicholas tube flow test data, the concrete expression of the resistance coefficient of open channel in each flow regime and flow regime is deduced Get the verification of the measured data. In the process of derivation, the conversion of pipe flow coefficient and open channel resistance coefficient is realized by the equivalent diameter of open channel. Based on the different flow characteristics of each flow area, the roughness height formulas proposed by Christoffersen and Jonson are simplified. The calculated drag coefficient formula was used to calculate the sediment carrying capacity of rivers and marine nearshore. The results show that the measured values agree well with the calculated values, and the unification of expressions of drag coefficients in all flow zones is favorable for the calculation of sediment carrying capacity. .