Coupled DEM–CFD simulation of drying wood chips in a rotary drum – Baffle design and model reduction

Autor: Martin Mönnigmann, Marc Oliver Berner, Viktor Scherer, Florian Sudbrock
Rok vydání: 2016
Předmět:
Zdroj: Fuel. 184:896-904
ISSN: 0016-2361
DOI: 10.1016/j.fuel.2016.05.054
Popis: In this contribution coupled DEM–CFD simulations of convective drying of wood chips in a baffled laboratory rotary dryer are presented. Due to the anisotropy of the biogenous (fibrous) material a three-dimensional spatial resolution of inner particle transport processes within the DEM code has been incorporated. The drying law is based on a diffusion approach. The simulations show that L-shaped baffles lead to higher drying rates than straight baffles. L-shaped baffles lead to a more even distribution of the particles across the cross-section of the drum where a larger amount of the wood chips are located in regions of hot, unsaturated air. However, the assumption of anisotropic transport properties within the wood chips and the subsequent solving of the associated differential equation of the three dimensionally resolved particle requires high computational effort. Therefore, the second purpose of the paper is to propose a model reduction method for single particle DEM-models based on proper orthogonal decomposition to reduce computation times. Specifically, we assess the impact of these methods on the computational complexity of the single particle models. The results show that even with a basic implementation a considerable reduction can be achieved on the single particle level. While our results only apply to the specific example treated here, it is evident that the effect of model reduction grows with grid size.
Databáze: OpenAIRE
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