A genetic algorithm-based approach for numerical solution of droplet status after Coulomb fission using the energy conservation method

As a droplet moves, due to evaporation at the surface, the droplet size is gradually reduced. Due to decreasing the size of the droplets moving in the spray core, the surface charges become closer and the repulsive force between the charges increases. When the Coulombic force overcomes the surface tension force (Rayleigh instability) the droplet breaks into smaller droplets (Coulomb fission). The present study predicts droplet Coulomb fission and droplets trajectories of steady spray plume in a monodisperse Electrohydrodynamics (EHD) spray within a Lagrangian framework. Droplet fission is simulated based on the principle of minimum free energy using the Genetic Algorithm (GA) and droplet trajectories are predicted using the Lagrangian single-droplet dynamic tracking method. The numerical model is validated by comparing the model predictions with the experimental and previous modeling results. In the current method, an optimization method for minimizing the energy in the minimum energy principle is utilized to avoid any simplifying assumptions, such as number of sibling droplets and charge distribution on their surfaces which may affect the physics of the problem. According to the process of the present solutions and results, it is clearly seen that the developed method has sufficient accuracy and precision.