Scalar structure of turbulent partially-premixed dimethyl ether/air jet flames

This work presents results of temperature and major species measurements from two turbulent piloted, partially-premixed dimethyl ether (DME)/air jet flames with Reynolds numbers of 29,300 and 58,600. These results are intended to provide a first set of multi-scalar data from a new flame series for the investigation of turbulence-chemistry interaction and the validation of turbulent combustion models using a complex, oxygenated fuel, DME. The current work investigates two Reynolds number cases from the complete DME flame series (five flames) that were formulated to be similar to the well-known Sydney/Sandia piloted jet burner flame series A-F using methane fuels. The flame structure is examined using ensemble mean and rms radial profiles at various axial positions downstream of the nozzle exit as well as statistics conditioned on mixture fraction. Finally, selected results of the two cases are compared to the original methane-based configurations. Finite-rate chemistry effects such as local extinction and re-ignition and their impact on the scalar flame structure are found to be different in the DME/air jet flames as compared to the methane-based jet flames.