FULLY-DEVELOPED FORCED-CONVECTION HEAT-TRANSFER IN CYLINDRICAL PACKED-BEDS WITH CONSTANT WALL HEAT FLUXES

Hydrodynamically and thermally fully developed forced-convection heat transfer in cylindrical packed beds with constant wall heat fluxes is theoretically examined on the basis of our previous two-dimensional, d istributed parameter model taking into account the effects of non-Darc y, variable porosity and radial thermal dispersion. Several system par ameters including the Prandtl number, Pr, the ratio of the thermal con ductivity of solid to that of fluid, kappa, the bed radius to particle diameter ratio, Gamma, and the particle Reynolds number, Re-p, are va ried. The adequacies of some approximations to the governing equations are also examined in detail. It is found that the effects of the afor ementioned system parameters on the relationship between the Nusselt n umber and RepP gamma are the same as those observed for packed beds wi th constant wall temperatures, but values of the Nusselt number are ge nerally greater than those obtained under the boundary condition of co nstant wall temperature, as long as values of Gamma, kappa and RepP ga mma are kept constant.