Performance assessment of wall-modeled large-eddy simulation for modeling aeolian two-phase flow

Abstract

Wall-modeled large-eddy simulation (WMLES) is an effective way to improve the computational efficiency of two-phase flow. Based on a wall-resolved large-eddy simulation (WRLES) of aeolian two-phase flow at sand-free friction Reynolds number of Reτ=4200, the performance of different subgrid stress (SGS) and wall models in modeling aeolian two-phase flow are checked. Three classical eddy-viscosity-type SGS models are employed, i.e., Smagorinsky (SMAG) model, dynamic Smagorinsky (DYNA) model and scale-dependent dynamic (SDDY) model. The involved wall models are two equilibrium wall models and a non-equilibrium wall model. By comparing the WMLES and WRLES of sand-laden flow, it is found that wall models have less influence on particle velocities for the same SGS model. On the contrary, the particle volume fraction and mass flux strongly depend on the SGS and wall models. Although, the performance of WMLES with different models varies from case to case, the combination of dynamic Smagorinsky model and integral model performs the best in this case. By analyzing the particle and fluid stress, we suggest that the influence of particles on LES models is in urgent need.