B3

The project B3 develops an efficient numerical description of the radiative heat transfer in moving granular assemblies, utilizing experimental and numerical methods. In actual systems, the nature of radiative transport lies in between limiting cases, long range directional exchange among solid surfaces enclosing a large participating gas volume and local short range exchange within a densely packed particle bulk. Here, the radiative interaction with the interstitial gas volumes is negligible and omnidirectional diffusion prevails, which can be expressed as an increase in effective thermal conductivity. For the systems of interest in BULK-REACTION, the diffusion limit is usually not approached because particles are too large and the direct short-range interchange of radiation of particles of arbitrary shape has to be accounted for explicitly. The directional long range transfer and this local direct exchange must coexist in one domain and interfaces with a gradually changing share of both regimes must be able to move across the domain over time. This will be achieved by merging the widely used Discrete Ordinates Method (DOM) approach with a short range model for the dense system. Spectral redistribution, induced by varying surface temperature of the objects involved, will be accounted for in the dense bed.