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A 2-D numerical model was proposed to investigate the ignition of liquid fuel droplets in convective environments at high temperature. This model employed a skeletal mechanism consisting of 34 reactive species and 56 elementary reactions, rather than one-step overall reaction as in normal 2-D droplet ignition models, because the skeletal mechanism for n-heptane reproduces ignition delay times at various temperatures and pressures reasonably well. In present investigation an emphasis was addressed on the comparative analysis of suitability of the model, particularly numerical simulations were compared with experiments available in the literature, or for N-heptane droplets ignition in the convective air at temperature in a range of 1100K∼1400K and velocity of 2m/s. The ignition delay time and ignition position were obtained using an ignition criterion based on OH radical mass fraction. The flame behavior after ignition was also studied comparatively. The agreement between numerical simulation and experiments is reasonably good.

A series of experiments was conducted to understand the combustion characteristics and evaporating interface behavior of liquid fuel in capillary tubes. The flame shape, interface location of fuel front and tube outer surface temperature was visually observed and measured using CCD and IR camera, respectively. With fuel supply rate increasing, the interface location rose to tube exit and the temperature gradient of the outer tube surface increased, and consequently the evaporating interface tended to be unstable. The prediction of interfacial evaporation using available models was compared with the experimental measurements, indicating that this kind of highly non-equilibrium micro combustion with phase-change could not be described by normal mechanisms.