Multiple fuel droplets evaporation is investigated by means of three-dimensional numerical simulations performed in a in-house code. The purpose of this investigation is to study the processes of droplet evaporation and micro-mixing, which play a crucial role for fuel distribution in the gaseous phase. The mathematical model consists of balance equations in Lagrangian and Eulerian frameworks for liquid and gas phases, respectively. Based on the two-way coupling concept, a series of source terms accounting for mass, momentum and energy interactions between two phases are added to the corresponding balance equations of each phase. In order to validate the Lagrangian evaporation model, first, numerical simulations of a single droplet evaporation are performed and the results are compared to experimental data, afterwards, numerical simulations of multiple fuel droplets evaporation are performed for ambient temperature and pressure of 2000 K and 1 atm, respectively. The droplets are randomly distributed in the central region of a cubic domain as a spherical shape with a mass load ratio of 0.027. For all the simulations performed in this work, including the validation of the Lagrangian evaporation model and the two-phase flow simulations, n-heptane is evaporated in a nitrogen gaseous medium. It is observed, as expected, that increasing the dispersed phase mass fraction decreases the ambient gas temperature and increases the ambient fuel vapor concentration; therefore, the droplet lifetime increases. The results finally reveal that the consideration of the two-way coupling in the mathematical model, even in the dilute case, could lead to some significant effects on the
predictions of evaporation process.