DETERMINATION OF THE FIXED-BED WALL HEAT-TRANSFER COEFFICIENT USING COMPUTATIONAL FLUID-DYNAMICS

Fluid flow and heat transfer in a Fixed bed of tube-to particle-diamet er ratio 2.14 is modeled by an arrangement of three staggered spheres in a tube. The problem is solved numerically by a finite element metho d applied to the three-dimensional incompressible Navier-Stokes equati ons and the energy equation. Results are obtained for Reynolds numbers in the range 25-101, with a Prandtl number of 0.72 and particle condu ctivities in the range 0.25-48.0 W/(m K). Wall heat transfer coefficie nts obtained from the calculated temperature profiles are in good agre ement with values predicted by a model-matching theory using correlati ons based on experimental measurements.