Large Eddy Simulation (LES) of turbulent non-Newtonian flows involves two additional closures, namely the Non-Newtonian SubGrid-Scale (NNSGS) stress tensor and filtered viscosity. Here, dynamic closures are proposed for NNSGS, eliminating the need for model calibration. In addition, for the primary evaluation of LES closures, two canonical case studies are designed by the extension of Newtonian forced Burgers turbulence to include power-law viscosity rheology. The characteristics of the proposed non-Newtonian turbulence are studied carefully using direct numerical simulation. For instance, it is revealed that the shear-thinning effect intensifies the small-scale motions and elevates the energy spectrum function at high wave-numbers. The subsequent a priori and a posteriori studies manifest that the NNSGS modeling is important for the present test cases. The omission of this term results in the under-prediction of kinetic energy due to the substantial backscatter effect of NNSGS. The proposed dynamic Smagorinsky based closure is recommended, based on the correlation coefficient measure in the a priori tests and the energy spectrum function in the a posteriori tests, for LES of turbulence at high shear-thinning rheology. The use of the present NNSGS dynamic model improved the predictions, however, further effort to achieve more accurate closures for NNSGS and especially the filtered viscosity is still necessary in future studies.

湍流非牛顿流动的大涡模拟 (LES) 涉及两个额外的闭包，即非牛顿子网格尺度 (NNSGS) 应力张量和过滤粘度。在这里，为 NNSGS 提出了动态闭包，消除了模型校准的需要。此外，对于 LES 闭合的初步评估，通过扩展牛顿强迫 Burgers 湍流以包括幂律粘度流变学设计了两个典型案例研究。使用直接数值模拟仔细研究了所提出的非牛顿湍流的特性。例如，研究表明剪切稀化效应会加强小尺度运动并提高高波数下的能谱函数。随后的先验和后验研究表明，NNSGS 建模对于当前的测试用例很重要。由于 NNSGS 的大量反向散射效应，该术语的省略导致对动能的预测不足。基于先验测试中的相关系数测量和后验测试中的能谱函数，建议基于动态 Smagorinsky 闭合，用于高剪切稀化流变学中的湍流 LES。使用当前的 NNSGS 动态模型改进了预测，但是，在未来的研究中仍然需要进一步努力实现更准确的 NNSGS 闭合，尤其是过滤粘度。基于先验测试中的相关系数测量和后验测试中的能谱函数，建议基于动态 Smagorinsky 闭合，用于高剪切稀化流变学中的湍流 LES。使用当前的 NNSGS 动态模型改进了预测，但是，在未来的研究中仍然需要进一步努力实现更准确的 NNSGS 闭合，尤其是过滤粘度。基于先验测试中的相关系数测量和后验测试中的能谱函数，建议基于动态 Smagorinsky 闭合，用于高剪切稀化流变学中的湍流 LES。使用当前的 NNSGS 动态模型改进了预测，但是，在未来的研究中仍然需要进一步努力实现更准确的 NNSGS 闭合，尤其是过滤粘度。