一种基于粘性耗散的动态黏度计算方法

A Method of Modeling Dynamic Viscosity Based on Viscous Dissipation

基于剪切功率的耗散机理,提出了一种计算振动剪切流场中聚合物熔体动态黏度的粘性耗散法,并建立了理论模型。运用粘性耗散法,计算了简单振动剪切流场中Maxwell流体的动态黏度,得到了与传统方法相一致的结果,从而验证了理论模型的正确性。通过讨论振动叠加流场中Maxwell流体的动态黏度,分析了粘性耗散法的应用局限性。最后,通过动态流变实验,发现粘性耗散法对于小振幅范围的振动剪切流具有较好的预测能力。

Based on dissipation mechanism of shearing power, a new method of modeling dynamic viscosity of polymer melts in vibrating shear flows was proposed in this paper. And theoretical models were formulated. Using the method, the dynamic viscosity of Maxwell fluid in simple vibrating shear flow was found uniform with results using a traditional method. The result uniformity showed validity of the method. And the prediction ability of the method was discussed for vibrating shear flows superposed on steady flow. A deficiency of the model for the superposed flows was found and the causes were analyzed. Finally, Rheological experiments were carried out. The experimental investigation showed a good agreement with the theoretical prediction in a bound of small amplitude.