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.
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Numerical Simulations on Aluminum Combustion in Two Different Reference Frame
Aluminum powder has been commonly used as the energetic material in solid propellants due to its high energy density. However, in actual combustion scenarios, not all aluminum powder is able to completely burn before reaching the nozzle, owing to the complicated physics of aluminum combustion. Due to this complexity, many studies have relied on analytic solutions instead of directly solving the Navier-Stokes equations. These earlier studies exhibit limitations, such as the inability to explain mass and heat transfer occurring at the interface or simulate 3-D fluid dynamics. In this study, the Volume of Fluid (VOF) method was employed to conduct direct numerical simulations of aluminum droplet evaporation. Subsequently, the developed model was compared and assessed against the evaporation model provided by the Lagrangian solver.
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- Award ID(s):
- 2244324
- PAR ID:
- 10591086
- Publisher / Repository:
- American Institute of Aeronautics and Astronautics
- Date Published:
- ISBN:
- 978-1-62410-711-5
- Format(s):
- Medium: X
- Location:
- Orlando, FL
- Sponsoring Org:
- National Science Foundation
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