中文摘要：

研究非牛顿流体管流的传统广义流性指数法是在假定广义流性指数n’为常数的前提下得到的。严格意义上只有幂律流体才符合这种情况,对于其它非牛顿流体只能做n’为常数的近似处理。另外,没有给出n’的通用计算方法,后来的研究都沿用n’为常数的假设。本文在总结分析传统广义流性指数法不足及前人研究基础上,对该方法进行了扩展应用。基于通用圆管流量方程给出了各流变模型管壁剪切速率、剪切应力计算方法,进而给出了n’的理论计算方法,这种方法不以n’是常数为前提,且适用于所有流变模式。在不假定n’为常数的情况下导出了广义雷诺数的一般表达式,建立了统一的压耗计算模型。与室内实验数据对比分析表明,该方法对非牛顿管流压耗具有很高的预测精度。该方法的提出为一些复杂但更为精确的流变模式在工程领域推广应用打下了良好的理论基础。

英文摘要：

Traditional generalized flow index method for non-Newtonian fluid flow in pipes is obtained on the premise that generalized flow index （n’） is constant over all range of shear rates. Strictly speaking, only power law fluid conforms to this situation, all other non-Newtonian fluid have to do approximation assuming n’ to be a constant. In addition, predecessors didn’t give the calculation method for n’. All most of later research also based on the hypothesis that n’ was constant. We summarized and analyzed the deficiency of traditional generalized flow index method. The generalized calculation for wall shear rate and shear stress for all common rheological was obtained based on the generalized flow rate equation. And then, we gave the theoretic calculation method of n’ for all time-independent non-Newtonian fluid. This method is applicable to all common rheological models without the assumption that n’ is constant. Moreover, we derived the general expression of generalized Reynolds number and then gave the theoretic calculation method of n’ for all time-independent non-Newtonian fluid and gave a utility pressure loss calculation model. A set of measured hydraulic data were utilized to evaluate this model. The results show that it can precisely calculate pipe flow parameters for all types of different non-Newtonian flow. The method proposed will lay a foundation for the application and popularization of complex but more precise rheological models in engineering.