Since several years Lagrangian methods (i.e. particle based numerical solvers/methods like discrete element method or DEM) are used to investigate the interaction of particles. Various coupling schemes are developed within recent years which allow the investigation of interaction between Lagrangian and Eulerian frame of reference (i.e. particles and fluids). Presently these methods are able to resolve physical phenomena on a detailed level and give access to develop and implement further equations for e.g. thermochemical aspects. Unfortunately, DEM demand a lot of computational resources. This is owed to the method since for physical correctness every interparticle contact needs to be resolved. Consequently, suitable timesteps of the simulation are very short and the computation efforts rises fast by increasing the particle number. Industrial systems like a blast or reduction furnace or refractory metal sinter processes usually inhere huge particle numbers putting the direct simulation to an unsatisfying level. Different approaches like artificially enlarge the particles to reduce their number (coarse graining), utilising GPUs, etc, are raised to overcome or attenuate these problems (Project 4.4 – Fast Simulations will investigate a novel approach). The common methods showed serious limitations to be used within metallurgical aggregates like blast or shaft furnaces since they are characterized by high and very low dynamic zones as well as small and huge geometric details. A global model thus needs to comprise the information of locally detailed investigations to be used to design computationally efficient modelling.

Research within funding period 1 showed promising results for detailed model developments and first applications towards a direct reduction shaft. Still several details are not included in the desired fidelity and should be enhanced within this project.