Locally Resolved Simulation of Gas Mixing and Combustion Inside Static and Moving Particle Assemblies

Abstract

AbstractResolving the flow field within the voids between particles of reacting granular assemblies is essential to obtain correct conversion rates. Due to the associated computational cost, a high spatial resolution cannot be employed on the device‐scale. A combination of a locally resolving and an averaging method is suggested. Namely, the so‐called blocked‐off method is used to resolve the voids between particles within prescribed regions, while the volume‐averaged method is applied in the remaining domain. For a nitrogen jet injected into a regular simple cubic packing of spherical particles passed by a cross‐flow of air, the jet dispersion is too low when applying the volume‐averaged method for the whole computational domain. The same is also observed in a reacting methane jet flowing into a bed of arbitrarily packed particles with air cross‐flow, where the locally resolved approach predicts significantly larger local reaction rates.