In the actual spray combustion fields, coupled combustion process should be occurred, between the pre-evaporate fuel component and remaining liquid droplets. Therefore it is insufficient to clarify the fundamental spray combustion mechanism with use of only droplet or only premixed mixture analyze method. In this study, the premixed mixture-droplets coupled combustion field was focused, as a model of the actual spray combustion field. In the experiments, the effect of the flame pattern and the burning rate constant by the interference between the droplets were clarified with the variation of droplets fuel. Besides, effect of the premixed gas surrounding the droplets was clarified by the experiment on coupled combustion. The experiments were carried out under the normal gravity field and the microgravity field to estimate the effect of convection in combustion field.
