DEVELOPMENT OF DROP/WALL INTERACTION MODEL FOR APPLICATION IN ENGINE CONDITIONS

The impact process of fuel drops on a solid dry surface under engine relevant conditions were studied using a numerical method based on smoothed particle hydrodynamics (SPH). The post-impingement properties (mass, velocity, and location) of the splashed secondary drops were analyzed. A drop/wall interaction model was developed on the basis of the SPH simulations. Numerical results show that the mass of the secondary drop will increase as the kinetic energy of the incident drop and surface temperature increase. For contact-splash, the radial location of the secondary drop increases linearly as the kinetic energy of the incident drop increases, while no clear trend was found for film-splash. The height of the secondary drop is also randomly distributed for both contact-splash and film-splash. The velocities of secondary drops will increase first and then decrease as the kinetic energy of the incident drop increases. The effects of impact angle on the impact outcomes were also characterized and incorporated into the model. It was found that the impact angle affects the distribution of the secondary drops. The proposed drop/wall interaction model derived from the present SPH study can be readily implemented for engine spray/wall impingement simulation.