The expansion of a turbulent bluff-body stabilised non-premixed methane flame after spark ignition is studied here by performing Large Eddy Simulations. Conditional Moment Closure with a 19-species reduced chemical mechanism is employed to model the combustion process. The spark is modelled as a source term in the enthalpy equation and its parameters are similar to those in the equivalent experimental study. The expansion process can be predicted with good accuracy and refining the CMC mesh and using a chemical mechanism appropriate for fuel-rich combustion improves the predictions, at least at a qualitative level, compared to a past numerical study of the same burner. The name expands mostly due to turbulent diffusion and convection by the recirculating flow. The overall flame is stabilized when enough of the recirculation zone has ignited. The simulations are in good agreement with quantitative and qualitative experimental observations.
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