Influence of inlet how conditions on the performance of a swirl-stabilized combustor burning liquid fuel spray

A numerical model of liquid fuel spray combustion is developed to study the effects of inlet flow conditions of primary and dilution air on the performance of a swirl-stabilized axi-symmetric combustor. The model is based on two-phase stochastic separated flow approach. A standard k-epsilon model with logarithmic law of the wall for the near-wall region is adopted for the solution of the gas phase turbulence. The chemical reaction is taken as a single step, irreversible, global one with the rate determined by the kinetically and diffusionally controlled rates. The liquid spray is divided into a finite number of droplet classes with the size distribution following a probability function. It has been observed that an improved pattern factor and better combustion efficiency can be obtained when both the primary and the dilution air streams enter the combustor with swirl, but in the counter-rotating directions. However, the combustor pressure loss factor increases for the counter-rotating flow entries of the primary and the dilution air compared to the co-rotating air entries or to the swirled primary and non-swirled dilution air entries. Copyright (C) 2000 John Wiley & Sons, Ltd.