(193c) CFD Modeling of Oxy-Natural Gas Furnace Using Detailed Kinetic Modeling with and without the Use of Chemistry Acceleration
AIChE Spring Meeting and Global Congress on Process Safety
Wednesday, April 25, 2018 - 2:20pm to 2:45pm
The test case considered in this paper is a coaxial high momentum oxy-natural gas flame in a refractory lined furnace at a thermal input of 0.8 MW . Radial profiles of velocity, temperature and species are compared between experiments and simulations at several axial locations downstream of the burner. The detailed chemical kinetic mechanism GRI3.0 was used to represent the chemical kinetics and the effect of chemistry acceleration techniques such as (a) In-situ Adaptive Tabulation (ISAT), (b) Clustering and (c) Dynamic Mechanism Reduction (DMR) on the predicted results was analysed. ISAT  enables speed up of complex chemistry simulations by storing and retrieving approximate reaction mapping solutions related to the chemical state space during run time. The clustering method groups cells with similar thermal and chemical states before integrating the averaged state for the group which in turn causes substantial speed-up. The DMR methodology is based on Directed Relation Graph (DRG) algorithm  where the mechanism is dynamically reduced in every cell at every iteration by identifying and solving only those species that substantially change over the reaction step thereby reducing overall computational time. The speed up achieved for each of the acceleration techniques and the associated accuracy is reported in this study.
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