2025/11/12 by Amani, E., Ahmadpour, A., Aghajari, M. J. · 1 citation
Chemical Engineering · Engineering · #Computational Fluid Dynamics and Aerodynamics #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Fluid Dynamics and Turbulent Flows #Rheology and Fluid Dynamics Studies
paper · doi:10.48550/arxiv.2511.09687
openalex publication_date 2025/11/12 · openalex created_date 2025/11/15 · openalex updated_date 2026/07/28
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.