The project involves numerical investigation of iron particle combustion using immersed boundary method. This is a part of the Clean Circles project, which collaborates scientists from multiple disciplines to explore how iron and its oxides can be used in a cycle as a carbon-free energy carrier.
Metals are gaining attention as promising carriers of energy. Among different metals, Iron is considered as an important candidate due its favorable properties and availability. The oxidation (combustion) of iron particles is still an open area of research in the scientific community. This is mainly because Iron as a fuel differs significantly from other solid fuels such as coal or biomass. In contrast to other fuels, during combustion of iron particles only heterogeneous reactions take place and no fuel volatiles are released. A porous layer of different solid iron oxides is formed as an outer shell, which represents a further transport resistance for the diffusion of oxygen to the inner reactive surface. This multi-layered porous structure results in a complex coupling of the chemistry and transport processes, which is insufficiently understood so far. The present study mainly focuses on the change in volume of the iron particle during the combustion process and how it affects the overall heat, mass and momentum exchange in the boundary layer. In addition, we also investigate different particle models to account for these effects.