Hybrid RANS/PDF calculations of sydney swirling flames

In this work, we perform steady 2D axisymmetric RANS and hybrid RANS/PDF calculations to predict the turbulent flow and mixing fields of swirling inert flows and flames. The cases studied, N29S054 and SM1 respectively, are bluff body burner flows, studied experimentally at Sydney University. Turbulence is modeled with a non-linear k-ε type model, taking into account effects of rotation and streamline curvature on the turbulence. Flow field predictions are in reasonable agreement with experimental data. For the reacting flow, agreement for mean mixture fraction and mixture fraction variance with experimental results is less satisfactory. Yet, the mean temperature field is quite well reproduced. We compare presumed and transported scalar PDF simulation results, with the same laminar flamelet model for chemistry. The influence of the micro-mixing model is small in our case. The mixing model constant Cφ, has a stronger influence, through the mixture fraction variance