Numerical modelling of a CAN combustion chamber with swirler using probability density functions (PDF) and eddy dissipation model (EDM)

• A comparative study is conducted for a can combustor with reactive swirling flow • High-fidelity LES performed for comprehensive comparison with RANS • Intricate combustion-turbulence dynamics elucidated via swirl number contours • Elevated levels of swirl are evident in the combustion region This study employs a well-established experimental setup, involving a can combustor with swirling, recirculating, and turbulent reactive flow to evaluate the performance of combustion and turbulence modelling within the combustion chamber. Two distinct flame types, differentiated by varying fuel and air flow rates, were analysed using multiple turbulence models and a high-fidelity Large Eddy Simulation ( LES ) approach in conjunction with available combustion models to investigate the detailed flow physics and combustion behaviour. The numerical results were validated against experimental data to assess model accuracy. In addition to temperature distributions and species mass fraction profiles, iso-surfaces of temperature and fuel mass fractions and turbulent kinetic energy (TKE) contours were presented to gain a more comprehensive insight into the flame structure. It has been established that, for all models of turbulence, the reduced turbulent kinetic energy has a minimum value of 4 and a maximum value of 45. The present study observed a peak reduced temperature value for the EDM combustion model, with a difference of x / D ∼ 0.2 compared to the PDF combustion model. This finding demonstrates that the EDM model predicts the flame to be closer to the entrance of the fuel oxidizer inlet. The study systematically investigates the influence of geometric configuration and swirler design on recirculation zone formation and their role in stabilizing flames under non-premixed combustion conditions.