VLE-Based High Pressure Stationary Droplet Evaporation at Spray Detonation Conditions

This paper numerically investigates the evaporation characteristics of a single n-dodecane fuel droplet in high-pressure nitrogen environment relevant to rotating detonation engines. A validated computational fluid dynamics solver coupled with real-fluid thermophysical models is utilized. The effects of pressure, droplet temperature, and ambient gas temperature on the evaporation rate are analyzed by tracking the droplet diameter evolution. Two interface tracking techniques, namely a mean density-based method and a novel vapor-liquid equilibrium-based method, are implemented and compared. The results show appreciable deviations from the classical D²-law for droplet evaporation. Increasing the ambient temperature and droplet temperature (toward critical point) substantially accelerate the evaporation process. Meanwhile, higher pressures decrease the evaporation rate owing to slower species/thermal diffusions. At certain conditions, discernible differences are observed between the two interface tracking methods indicating deficiencies in the simple mean density approach. The paper demonstrates an effective computational framework for transcritical droplet evaporation simulations. And the generated high-pressure droplet evaporation datasets can inform sub-model development for spray combustion modeling.