Combustion of strongly-interacting linear droplet arrays

Experiments were conducted to study the droplet vaporization rate, the gross flame characteristics, and the effect of buoyancy of closely-spaced, strongly-interacting, linear arrays of two and three droplets. Intensity of buoyancy was controlled by varying the pressure and oxygen concentration within the combustion chamber. Results show that the burning process depends on the initial array configuration, that the droplet vaporization rate does not follow the d²-law, that the measured rate is substantially below the existing theoretical predictions except towards the latter part of the droplet lifetime at which good agreement exists, and that buoyancy can significantly enhance the vaporization rate to compensate for the interference effect. Droplet heating is retarded due to interference and is identified, together with array configuration, buoyancy, and the mergedness of the flame as the important factors governing multi-droplet combustion.