A bluff-body combustor, with recirculation zone and simple boundary conditions, isideal as a compromise for an industrial combustor for validating combustion models. This combustor,however, has proved to be very challenging to the combustion modellers in a number ofprevious studies. In the present study, an improved prediction has been reported through betterrepresentation of turbulence effect by Reynolds stress transport model and extended upstreamcomputational domain. Thermo-chemical properties of the flame have been represented bya laminar flamelet model. A comparison among reduced chemical kinetic mechanism of Petersand detailed mechanisms of GRI 2.11, GRI 3.0, and SanDiego has been studied under the laminarflamelet modelling framework. Computed results have been compared against the well-knownexperimental data of Sydney University bluff-body CH4/H2 flame. Results show that the laminarflamelet model yields very good agreement with measurements for temperature and majorspecies with all the reaction mechanisms. The GRI 2.11 performs better than the other reactionmechanisms in predicting minor species such as OH and pollutant NO. The agreement achievedfor NO is particularly encouraging considering the simplified modelling formulation utilized forthe kinetically controlled NO formation.
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