Simulations of Melting in Fluid-filled Packed Media due to Forced Convection with Higher Temperature

An original CFD-DEM method, named as CD-MELT, is developed to model the isothermal melting of a packed bed subjected to a forced convection with higher temperature. The formulation of CD-MELT allows a high degree of representation of the melting process. With specific melting parameters, the particles in the packed bed undergo mass, diameter and temperature change individually, and the packed bed is reconfigured afterward through particles collision and contact. The phase changes are accounted for via source terms using a mass loss fraction, ranging from 0 (initial mass) to 1 (complete melting), which is introduced for the first time and differs from other existing models. The CD-MELT's predictions are compared with the results from an earlier experimental study on the melting of a single ice sphere as well as a packed bed of ice spheres due to a forced convection of warm water. The comparison is found to be satisfactory despite the use of a coarse mesh, and the computation run is stable despite the varying mesh-particle size ratio. Finally, the effects of spring constant and restitution coefficient in the particle collision model are further investigated for the case of a non-floating packed bed under forced convection. Recommendations are made on how their suitable values can be determined in future melting studies. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The CD-MELT method is developed for modeling the isothermal melting of a packed bed under forced convection, allowing a high degree of representation of the melting process. It introduces a mass loss fraction for accounting for phase changes, different from other existing models. Despite using a coarse mesh, the predictions are found to be satisfactory when compared with experimental results.