Nombre: VICTOR MAGALHÃES COSME
Fecha de publicación: 22/10/2025
Junta de examinadores:
Nombre |
Rol |
|---|---|
| DANIEL DA CUNHA RIBEIRO | Presidente |
| FERNANDA CAPUCHO CESANA | Examinador Externo |
| MARCELO SILVEIRA BACELOS | Examinador Interno |
Resumen: Collision between drops is a phenomenon found in both natural environments and industrial production. In the energy sector, this phenomenon is present in oilwater separation processes, fuel injection, and post-treatment systems forco mbustion gases. Although drop collision has been studied extensively for several decades, a large part of its dynamics still needs to be explored. This lack of understanding leads to uncertainty in the design of industrial processes. Most experimental and numerical simulation studies focus on the collision of two drops in a gaseous ambient. However, there are few quantitative studies on these collisions in the literature. Furthermore, issues such as the impact of film drainage time on simulations and the validation of a numerical model through dimensionless parameters can contribute to these studies by occupying a space that has been little explored until now. In this sense, the objective of this dissertation was to investigate, through direct two-dimensional numerical simulations, the dynamics of frontal collision between droplets, using the film drainage time parameter and dimensionless groups such as the Weber number, Reynolds number, specific mass ratio, and viscosity ratio on collision and recovery times, as well as the transition from coalescence to rebound regimes. For this, the conservation equations for mass and momentum were non-dimensionalized; the two-dimensional domain and adaptive mesh were defined as a function of the initial drop diameter; and a code was developed for the Basilisk® software to carry out the simulations. The results showed that the collision time is directly impacted by the film drainage time, unlike the recovery time, which did not change even for different drainage times. The values for the dimensionless drainage time equal to 0.35, for the coalescence condition, and 0.60, for the rebound condition, allowed for similarity with experimental data from the literature, confirming the validity of the model.
