Simulation of liquid drop impact on dry and wet surfaces using SPH method

Spray-wall interactions occur in many combustion devices and have significant effects on mixture distribution and combustion quality. This paper describes an advanced numerical method, based on smoothed particle hydrodynamics (SPH), for predicting the detailed outcomes of drop-wall interactions. SPH is a Lagrangian mesh-free method suitable for capturing the surface evolution of a deforming liquid. In simulating the drop impact on a dry surface, the present model was able to predict the spread of the drop on the wall, and the evolution of the predicted wall film diameter agreed with the experimental data. In simulating the drop impact on a wet surface with an existing liquid film, the model captured the formation of the crown, the generation of secondary droplets, and the eventual receding of the crown. Results show that as the impact velocity increased, both the maximum crown height and the time to reach the maximum crown height increased. These predictions agreed with the measurements for various operating conditions. This agreement indicates that the present numerical method has the potential to accurately predict the details of spray-wall interactions in combustion system environments.