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

Abstract

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 reliability 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 εs > 0.05 ~ 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 (εs = [0.01, 0.65], Res = [1, 1000]) from literature is proposed and analyzed.