Comparison of multicomponent fuel droplet vaporization experiments in forced convection with the Sirignano model

The vaporization of multicomponent fuel droplets was studied experimentally in a heated flow and the results were compared to the model proposed by Ab ramzon and Sirignano. The droplet was suspended on a permanent holder which was set up in a thermal wind-tunnel. This wind-tunnel was fitted with a vi deo recording system and an infra-red camera. The period during which the d roplet was suspended on the holder before the opening of the hot air flow d amper was recorded. This first sequence corresponds to the droplet vaporiza tion in natural convection, whose initial experiment conditions, especially diameter, temperature, composition of the droplet, are well known. Then th e damper was turn on, and the sequence of forced convection begun. The init ial diameter of the droplet was recorded by the video system. The other ini tial conditions of this second sequence cannot be determined experimentally . The distribution of temperature in the droplet and the surface temperatur e, the mass fraction distribution in the droplet and the surface mass fract ion were unknown. These unknown parameters were determined by coupling our experiment with a model using "the film concept" in natural convection. Exp erimental results were compared with the calculations and found satisfactor y, in natural convection as well as in forced convection initiated by this method. The method was tested in the case of a fuel mixture droplets (hepta ne-decane) for different initial concentrations and variable durations of t he sequence in natural convection. (C) 1999 Elsevier Science Inc. All right s reserved.