Analysis and development of homogeneous drag closure for filtered mesoscale modeling of fluidized gas-particle flows

Filtered mesoscale model can be formulated from highly-resolved continuum or discrete simulations. The embedded microscopic homogeneous drag closure (HDC) is of key importance in determining the relia-bility and accuracy of such simulations. This work investigates the effects of sub-input HDCs on filtered mesoscale predictions using highly-resolved simulations. Quantitative comparisons directly reveal that there are significant differences between the commonly-practiced Wen-Yu drag closure and the direct numerical simulation (DNS) based HDCs, especially for moderate and dense gas-particle flows. Moreover, the HDCs from DNS of static particles agree well with the benchmark data from DNS of dynamic gas-particle flows at very low Reynolds numbers for es > 0.05 similar to 0.10 while Wen-Yu drag is more applicable for the remaining range. Regarding that DNS is commonly implemented over a specific range of operating conditions, an enhanced HDC via refitting more elaborate high-fidelity DNS data (epsilon(s) = [0.01, 0.65], Re-s = [1, 1000]) from literature is proposed and analyzed. (c) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigates the effects of different HDCs on filtered mesoscale model predictions using highly-resolved simulations, showing significant differences between the commonly-practiced Wen-Yu drag closure and DNS-based HDCs in moderate and dense gas-particle flows. At low Reynolds numbers, HDCs from static particle DNS align with dynamic gas-particle flow DNS data, while Wen-Yu drag closure is more suitable for other ranges.