Flameless combustion technology can provide high efficiency with less emissions. Although spray combustion is prevalent in industrial furnaces, little research has been carried out to investigate ameless spray combustion. This article reports on numerical simulation of the Delft Spray-in-Hot-Coflow (DSHC) burner, which has been constructed to simulate and study ameless combustion of light liquid fuels. Reynolds Averaged Navier-Stokes (RANS) simulation is used with turbulence modeled through either the k-E or the Reynolds stress model (RSM). Moreover, two combustion models have been chosen: the steady amelet and the Flamelet Generated Manifold (FGM). This FGM is constructed from strained steady amelets and an unsteady extinguishing amelet. The interaction between turbulence and combustion is included via the gaseous PDF approach, which means the liquid phase has no direct impact on this interaction. Liquid fuel spray is described by a discrete phase model consisting of various submodels such as atomization, dispersion, and evaporation model. The combination of turbulence, combustion, and discrete phase models is validated by a dataset of liquid and gas-phase velocities as well as gas temperature profiles. Despite small discrepancy in the liquid-phase results, the numerical gas-phase velocities match well the experimental results for both turbulence models. The steady amelet model could not predict the observed liftoff and flame is always attached to the injector while the FGM model can show this liftoff. However, the quantitative prediction of liftoff height needs further investigation as long as the current FGM formulation does not provide accurately the liftoff height and temperature profile near the injector.
|Title of host publication||Proceedings of the 9th Mediterranean Combustion Symposium|
|Number of pages||12|
|Publication status||Published - 2015|
|Event||9th Mediterranean Combustion Symposium - Rhodes, Greece|
Duration: 7 Jun 2015 → 11 Jun 2015
|Conference||9th Mediterranean Combustion Symposium|
|Period||7/06/15 → 11/06/15|