Benchmarking study on scaling options for simulating dust detachment as part of the discrete element method (DEM) in mechanically agitated systems

Dust emissions generated during the mechanical processing of granular materials contribute significantly to the global problem of air pollution. To estimate the detachment of microscale dust particles typically adhering to macroscale bulk particles during mechanical interactions, the Discrete Element Method (DEM) represents a promising numerical approach. In the DEM, both dust-resolved and dust-unresolved models are employed, with the latter being computationally less demanding. In this study, a new highly efficient simulation framework was developed to further accelerate the modeling of dust detachment within DEM, aiming to enable the simulation of large-scale systems with improved computational efficiency. The framework combines dust particle quantity scaling (DPQS), which reduces the number of modeled dust particles by introducing representative probe dust particles, together with coarse graining (CG), a numerical technique that enlarges granular entities by bundling them into representative coarse-grained particles. The results obtained using the new framework were benchmarked against unscaled particle simulations employing dust-resolved and dust-unresolved detachment models for both single particle collisions at varying impact velocities and for a rotating drum at varying rotational speeds and batch material masses, evaluated across several evaluation parameters. Furthermore, dust detachment results from CG simulations applying different established contact scaling models were compared. The application of CG together with the most accurate contact scaling model achieved up to a 99% reduction in computational time for dust-detachment simulations in the rotating drum, while maintaining the same level of accuracy as the simulations without CG. • Development of scaling methods for efficient DEM-based dust detachment modeling. • Methods include dust particle quantity scaling and coarse graining. • Validation of both through dust-resolved DEM simulation results. • Application to dust detachment for single-particle contacts and in a rotating drum. • Evaluation of computational efficiency of scaling for varied dust detachment models.