Studies on Combustion of Single and Double Streams of Methanol and Methanol/Dodecanol Droplets

Results are presented on combustion characteristics of single and double droplet streams injected into hot gas environments. The droplets were composed of methanol/dodecanol mixtures or methanol. A flat-flame burner generated hot gases that were directed down an electrically heated flow tube. Droplets initially about 193 µm in diameter were injected through the center of the flat-flame burner and along the tube, where they ignited. Staged burning was observed for methanol/dodecanol droplets but not for methanol droplets. Burning rates decreased as the number of droplet streams was increased from one to two, and burning rates increased as the initial mass fraction of dodecanol was increased. The experiments indicated that droplet stream interactions influenced sooting and droplet disruption. The data also indicated that liquid species mixing rates were significantly larger in these droplets than in methanol/dodecanol droplets burned in previous reduced-gravity experiments--these differences are attributed to the droplet generation methods.