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[Display omitted] • Concentrated solar power and asphalt pavement recycling rely on granular heat transfer. • Interstitial gas contribution to heat transfer in dense systems is key for these applications. • A recently proposed model includes the effect of gas for dense, static systems. • We validate this model against experimental data from a heated rotating drum with glass beads. • The model shows excellent agreement with the experiment. Conductive heat transfer in granular material is important in many industrial processes. For dense systems where the materials have low thermal conductivity, much of the heat transfer will occur through interstitial gases. Industry requires flexible and efficient computational methods to capture these phenomena at scale. In this study, a recently proposed particle-based model that includes the contribution of the interstitial gases was validated using an experiment. This model was originally derived from a multi-scale analysis of static, random packings. To test this approach in dense, dynamic systems, the model results were compared to experimental data for glass beads in an indirectly heated rotating drum. Infrared (IR) thermography was used to track the temperature evolution of the glass beads and the drum wall temperature. Discrete element simulations were performed with the experimental wall temperature used as a transient wall boundary condition. Results from the simulation show good agreement with the experimental data both for the bulk average temperature and for the bed profile, demonstrating the model's ability to capture the gas contribution in dynamic systems. [ABSTRACT FROM AUTHOR]

This article investigates the use of coupled computational fluid dynamics (CFD) and discrete element methods (DEMs) to simulate heat transfer in an aggregate drum dryer used in the production of hot mix asphalt. To be properly coated by the asphalt binder, the aggregate must be completely dried, a process accomplished in a counter flow drum heated by a direct fire burner. Attached flighting is positioned inside the drum to facilitate heat transfer. Because direct observation is impossible, commercial codes from FLUENT and DEM solutions were used to simulate heat transfer from the burner flame to the aggregate. A fully reacting CFD simulation of a natural gas flame was coupled to a DEM simulation using an Eulerian model with heat transfer and momentum exchanged between the phases. Results indicate that the coupled model correctly captures the dominant mode of heat transfer (convection) as the particles are showered through the hot gases. The methodology established in the study provides a base for further investigation into optimising dryer performance. [ABSTRACT FROM AUTHOR]