Large-Eddy Simulation of Turbulent Spray Combustion in a Subscale Aircraft Jet Engine Combustor—Predictions of NO and Soot Concentrations

Abstract

Large-eddy simulation (LES) is applied to turbulent spray combustion fields in a subscale (1/2) aircraft jet engine combustor with an air-blast type swirl fuel nozzle and validity is examined by comparing with measurements. In the LES, Jet-A is used as liquid fuel, and individual droplet motion is tracked in a Lagrangian manner with a parcel model. As a turbulent combustion model, the extended flamelet/progress-variable approach, in which heat transfer between droplets and ambient gas including radiation and heat loss from walls can be taken into account, is employed. A detailed chemistry mechanism of Jet-A with 1537 reactions and 274 chemical species is used. The radiative heat transfer is computed by the discrete ordinate (DO) method. The equivalence ratio ranges from 0.91 to 1.29. The comparisons of the predicted droplet velocity and size, gaseous temperature, NO, and soot emissions with the measurements show that the present LES is capable of capturing the general features of the turbulent spray combustion fields in the subscale (1/2) aircraft jet engine combustor.