Are there wall effects on pressure drop through randomly packed beds of spherical catalyst particles?

Abstract For packed beds of low tube‐to‐particle diameter ratio (), pressure drop has been found to increase at low Re <100 and decrease at high Re >1000, compared to that in unbounded beds. Particle‐resolved CFD (PRCFD) in the low Re viscous region shows that widely accepted corrections overestimate the wall effect, and an improved correction formula is given. In the inertial region at high Re it is important to use accurate and consistent values for void fraction, which strongly affects pressure drop. Literature data show reasonable agreement with a correlation developed for unbounded beds (Dixon AG., AIChE J . 2023;69(6):e18035), when the void fractions for the bounded beds are used. PRCFD simulations also confirm this agreement, and only a small further correction is suggested for the remaining wall effects on fixed bed pressure drop in the inertial range, since the correlation uses the correct limit for as Re increases.