Numerical study of fuel droplet impact on heated surfaces using a smoothed particle hydrodynamics method 2019-01-0291
The impact of fuel droplets on heated surfaces is of great importance in internal combustion (IC) engines. In engine spray combustion simulation, the drop-wall interaction is usually simulated using models derived from experimental data and correlations. This paper presents a numerical method based on smoothed particle hydrodynamics (SPH), which can directly simulate the impact process of fuel droplets on solid surfaces at different temperatures. The SPH method is a Lagrangian mesh-free particle method. It discretizes fluid into a number of SPH particles and governing equations of fluid into a set of particle equations. By solving the particle equations, the movement of particles can be obtained, which represents the fluid flows. The SPH method is suitable for simulating large deformation and breakup of liquid drops without using additional free surface- or interface-tracking techniques. In addition to predicting the fluid motion, an evaporation model, based on SPH formulations, was developed to simulate the phase change. A film boiling model was also implemented for simulating the vapor generation resulting from the interaction of liquid and high-temperature walls. The present method is able to predict different outcomes of drop-wall interactions, such as spread, splash, breakup, and rebound. Based on the numerical results, a drop-wall interaction model for engine CFD simulations can be further derived.