Multi-Dimensional Flamelet Modelling for the LES of Pulverised Coal Flames

点击翻译按钮获取中文摘要

The primary objective of the proposed project is the development of multi-dimensional flamelet models for large-eddy simulation (LES) of solid fuel combustion. The project is composed of (a) the development of the flamelet model itself, (b) a priori simulation and validation by direct numerical simulation (DNS) and (c) a posteriori application of the flamelet method as a sub-grid model for LES. The second funding period will be used to improve the existing model (as developed during the first funding period) with respect to two technically highly relevant aspects. We will first consider cases with exhaust gas recirculation (EGR) and develop a flamelet-model that accounts for mixing between streams that are characterized by different reaction progress as would be typical for EGR. Then, the existing flamelet model will be extended to accurately capture the prediction of acidifying pollutants (NOx and SOx) and their precursors. This requires - as a precondition - a detailed approximation of the pyrolysis of all nitrogen and sulphur containing fuel components, and this will be achieved by the implementation of the well-established PoliMi-approach for the kinetics of the solid fuel conversion process. The final outcome of the second funding period shall be a validated, multi-dimensional flamelet-LES model for processes with EGR and pollutant formation that promises improved predictions when compared to existing RANS based solutions.