A New Approach to Fixed Bed Radial Heat Transfer Modeling Using Velocity Fields from Computational Fluid Dynamics Simulations

A new velocity-based approach to fixed bed radial heat transfer is presented. Axial and radial velocity components were averaged from detailed 3D computational fluid dynamics (CFD) fixed bed simulations of computer-generated beds of spheres and used to model radial thermal convection. The convection terms were coupled with a radially varying stagnant bed thermal conductivity in a 2D pseudocontinuum fixed-bed heat transfer model. The usual effective radial thermal conductivity k r and apparent wall heat transfer coefficient h w were not used, and there were no adjustable parameters. The radial and axial temperature variation predicted by the velocity-based model agreed well with the angular-averaged temperatures from the detailed 3D CFD simulations over the range 80 ≤ Re ≤ 1900 and for N = 3.96, 5.96, and 7.99.