Dimensionless numbers and correlations for characterizing heat transfer in a pulsating fluidized bed

Heat transfer behavior in a pulsating gas fluidized bed was investigated using Computational Fluid Dynamics. The average rate of heat transfer from the fluidizing gas to the solids was observed to increase with increasing average velocity at low to moderately high pulsation amplitudes. The temperature homogeneity of the fluidized bed improved with increasing pulsation amplitude but the average rate of heat transfer decreased when the maximum gas velocity at the peak of each pulsation cycle became too high. Temperature homogeneity decreased when high average velocities and high pulsation amplitudes were applied simultaneously. Both average rate of heat transfer and temperature homogeneity of the fluidized bed were high when a low or high pulsation frequency was applied but poorer at an intermediate value of pulsation frequency. The Buckingham II theorem was applied to derive two dimensionless numbers and to develop two dimensionless correlations which exhibited high goodness of fit with the simulation data obtained in this study.