Autoignition of isolated <i>n</i>-heptane droplets in air and hot combustion products at microturbine conditions

Spontaneous ignition of isolated n-heptane droplets with initial diameters 20–100 ?m is simulated using air at 4 atm and 700–1200 K, which includes the typical operating conditions recuperated microturbines. Because some fuel in a combustor may be sprayed or carried to near recirculation zone, simulations use mixture pure hot combustion products as oxidiser. The flame structures, evaporation times, autoignition times both physical fraction spaces for different are presented compared. variables examined include preheat temperature, amount dilution products, droplet diameter, oxidiser oxygen concentration. results show that microturbine fully evaporate before ignition, suggesting prevaporised concept suitable decreases delay time mainly by raising temperature. Low-temperature chemistry does not have significant effect on because adding even small can increase temperature higher than temperatures favourable low-temperature kinetics. cool only observed 100 low temperatures, but two-stage observed.