A detailed knowledge of the fluid flow profile is essential for a prop
er design of fixed-bed processes. For different sphere, ring and cylin
der sizes, radial velocity profiles were measured below the bed at emp
ty tube velocities of air of 0.5 m/s < v(0) < 1.5 m/s and the tube-to-
particle diameter ratios 3.3 < d(t)/d(p) < 11. The profiles show a vel
ocity maximum in the vicinity of the wall. As a consequence of the sta
tistical behaviour of packings, it was necessary to average velocity m
easurements after repacking in order to obtain representative flow pro
files. These averaged profiles were the basis for a model through whic
h the flow profile inside the packing can be calculated for spheres, c
ylinders and rings. The model is based upon the extended Brinkman equa
tion and the independently determined radial void fraction profiles. I
t considers an 'effective viscosity' for which correlations have been
derived. Comparison of simulated velocity profiles with exemplary liqu
id flow measurements inside the packed bed of Vortmeyer and co-workers
shows reasonable agreement. (C) 1997 Elsevier Science Ltd.