城市污水类非牛顿幂律湍流流动特性研究

Research on turbulent flow characteristic of urban wastewater as non-Newtonian exponential homogeneous fluid

城市污水的流动特性是其作为冷热源应用的关键问题。基于非牛顿流的切应力本构式、卡门对数分布与尼古拉兹实验,推导了速度分布、阻力系数与平均速度及雷诺准则的关系式,定义了特征雷诺数、特征广义雷诺数及其表达式,分析给出了层流、紊流的临界雷诺数,临界特征广义雷诺数为215。以特征广义雷诺数得到了阻力系数的理论曲线,对比了理论曲线与实验曲线及其与清水阻力曲线。以特征雷诺数表征的阻力系数与牛顿流体一致,阻力系数的理论与实验曲线吻合,为清水的400%以上。

Abstract： The wastewater＇s flowing characteristic is a key problem when using it as cooling and heating source. Based on the non-Newtonian stress formula,Karmdn logarithm distribution and Nikuradse experiment, the authors defined the characteristic Reynolds number, generalized characteristic Reynolds number, and the critical Reynolds number in laminar and turbulent flow. The critical generalized characteristic Reynolds number is 215. The resistance coefficient curve gained from general characteristic Reynolds number has been compared with the theoretical curve, the experimental curve and that of clear water＇ s. It was found that the resistance coefficient curve gained from general ebaraeterlstie Reynolds number is eonsistent with that of Newtonian fluid. The theoretical result of resistance coefficient, which is about 400% of that of clean water, matches with the experiment＇s.