Using a single flow-type parameter, we obtain analytic expressions for the unsteady and steady stress distribution for upper-convected Maxwell fluids in mixed shear and planar extensional flows, experimentally achieved in a four-roll mill. We propose two expressions to quantify the shear and extensional contributions to the strain rate magnitude. Finally, we conduct an analysis on the appearing rheological functions by defining apparent shear viscosity as a function of the flow-type parameter and the Weissenberg number.

中文翻译：

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混合剪切和平面扩展流中上对流麦克斯韦流体的理论预测

使用一个单一的流动类型参数，我们获得了在四辊轧机中通过实验获得的上对流麦克斯韦流体在混合剪切和平面扩展流中的非稳态和稳态应力分布的解析表达式。我们提出了两个表达式来量化剪切和延伸对应变率幅度的贡献。最后，我们通过将表观剪切粘度定义为流型参数和魏森伯格数的函数，对出现的流变性进行分析。