1. Evaporative Droplet-Particle Collision Dynamics
Liang-Shih Fan, Department of Chemical and Biomolecular Engineering, Ohio State University
This project aims to examine the contact process of a liquid droplet on a hot particle or surface, which is relevant to many engineering applications such as fluid catalytic cracking (FCC). The long-term goal of this research is to provide useful information for the optimal design of the feed nozzle assembly for efficient liquid droplet atomization and evaporation in petrochemical reactor systems. A combination of the theoretical, computational, and experimental approaches are utilized in this research project, with the emphasis on the formulation of a multi-scale model which is based on the direct numerical simulation and sub-grid modeling.
Experimental setup for the droplet-surface collision
A new 3-D numerical model is developed for a droplet in collision with a porous surface under the film-boiling condition. Experimental studies have also been carried out for the collision on a porous alumina surface, which has a pore size of 76nm and porosity of 34%. The simulated droplet shape, spreading factor, and droplet height are in good agreement with the experimental results. It is found that the dynamic characteristics of the droplet and the heat transfer characteristics of the surface are similar to the impact of droplets on non-porous surfaces. However, the droplet has a longer residence time, and also appears to be less stable on the porous surface.
Experimental and simulated droplet shape
Simulated vapour distribution