Abstract
Fixed‐bed reactors are widely employed in chemical processes because of their operational stability and high catalyst‐loading capacity. However, their performance is often constrained by complex flow behavior within the packed bed. In this study, particle‐resolved computational fluid dynamics was coupled with the discrete element method to construct fixed‐bed reactor structures comprising spherical particles. The effects of the bed‐to‐particle diameter ratio (
N
), bed height‐to‐diameter ratio (
H
), and standard deviation of the particle‐size distribution (STD) on the flow characteristics were systematically investigated. High‐precision three‐dimensional numerical simulations were conducted to elucidate the formation mechanism of the flow nonuniformity within the packed bed. Further, response surface methodology was employed to develop predictive models for the dimensionless variance. The results indicate that increasing
N
and reducing STD are crucial to flow uniformity enhancement. Overall, this study provides a theoretical basis and quantitative data support for the structural design and optimization of fixed‐bed reactors.