Numerical Investigation of Single Droplet Combustion in Turbulent Multicomponent Spray Flames

• Grant number: 25/11337-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: November 01, 2025
• End date: October 31, 2029
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: Fernando Luiz Sacomano Filho
• Grantee: João Vinícius Hennings de Lara
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The modeling of turbulent diluted spray flame is usually modelled using evaporation and condensation models, which produces an external flame sheet. Nonetheless, enveloped flames around isolated droplets have already been seen in experiments and simulations of turbulent liquid spray flames. Also named single or isolated droplet combustion, these flames have already been related to spray ignition processes and formation of soot. Reviewing the literature, it was clear that the modeling of enveloped flames should be included in simulations of turbulent diluted liquid spray flames. The development of such models ought to represent real fuels which are mixtures of different chemical species, like kerosene, and/or hydrophilic, like ethanol. Therefore they must be able to represent multicomponent mixtures, to consider transport phenomena inside the droplet and to consider non-ideal mixture thermodynamics. Developing single droplet combustion models (MCGI) will encompass the development of evaporation and condensation models (MEC) with the same capabilities, thus ensuring a gradual model development process, which will be based on pre-existing models in the literature. The simultaneous use of MEC and MCGI in a simulation must include a switch, also to be developed, that will chose which model to apply to each droplet. The new model will first be tested independently, to ensure its correct working and implementation. Then, it will be tested in the simplified scenario of a laminar flame in a quiescent monodisperse droplet mist. Lastly, after investigating flame-turbulence interaction, the model will be used in multidimensional turbulent spray flame simulations.