Solids Stress Closure Accounting for Wall Effects in Gas–Solid Fluidized Beds

Filtered two-fluid models (fTFMs) are usually employed to predict the flow behavior in large fluidized bed reactors. In fTFMs, other than the filtered drag force, the filtered solid stress also plays crucial roles, particularly at larger filter sizes. However, many traditional filtered closures have been developed using full-periodic domain data sets, which overlook the influence of wall boundaries. In practical fluidized reactors, wall boundaries can significantly impact the evolution of heterogeneous structures, potentially reducing the accuracy of filtered solid phase stress closures. This work improves the performance of existing filtered solid stress closure by introducing the impact of the wall boundary. The newly proposed closure is systematically evaluated in various posteriori validations, including a turbulent bed and two fast beds by coarse-grid two-fluid model simulations.