Large Eddy Simulation of a 100 kWth swirling oxy-coal furnace

Abstract

Large Eddy Simulation (LES) has been applied to the swirling 100 kW th OXYCOAL-AC test facility of Aachen University. A set of models to represent devolatilisation, volatile combustion, char combustion and radiation for oxy-coal combustion in an LES framework has been implemented and tested. A qualitative analysis of the flow behaviour and the overall coal combustion processes occurring within the furnace was made. The LES results for the flow field were compared to axial and tangential mean velocity measurements, showing good agreement, particularly in the upstream regions of the flame. The LES results were also compared to oxygen concentrations and gas temperature. Overall good agreement was observed in the upstream central regions of the flame, whilst downstream the LES overestimated the combustion rates. The results show the potential of using LES for more complex oxy-coal combustion burners and opens the way for applications to industrial furnaces.

Large eddy simulation of particle aggregation in turbulent jets

“…The maximum instantaneous ratio of sub-grid viscosity to laminar is approximately two, which suggest that the LES resolution is sufficient to capture the most energetic eddies. This is in line with results obtained with the same code inFranchetti et al (2016).5.2.2. Disperse phaseFigure 10shows the instantaneous and time-averaged particle concentration field N c .…”

A Validation Study for RANS Based Modelling of Swirling Pulverized Fuel Flames

“…Large eddy simulation (LES) and a RANS investigation of the same flame were performed by Chen and Ghoniem [26], where the standard and RNG k-ε model as well as the shear stress transport (SST) k-ω model were used as the RANSbased turbulence models. The same flame was analyzed using LES later on by Francetti et al [27], who placed a focus on high-resolution LES modelling. The LES and RANS analysis of a further flame with 60 kW th at the same rig was presented by Sadiki et al [28] for oxy-combustion.…”

Statistics of reaction progress variable and mixture fraction gradients of a pulverised coal jet flame using Direct Numerical Simulation data

“…Recently, CFD simulations have been performed for pulverised coal combustion using the Reynolds Averaged Navier-Stokes (RANS) [1] and Large Eddy Simulation (LES) [2][3][4][5][6] frameworks. These approaches are computationally less expensive, but require closures of several quantities appearing in the governing equations.…”