Numerical modeling of a slurry droplet containing a spherical particle

Abstract

A numerical investigation of the fundamental processes governing the momentum, energy, and mass exchanges between the solid, liquid, and gas phases of a vaporizing slurry droplet is presented. The axisymmetric configuration consists of an isolated slurry droplet with a large spherical solid particle in its core that is suddenly injected in a gaseous high-temperature, laminar, convective environment. The model allows for independent motion of the solid particle along the axis of symmetry of the slurry droplet, and considers variable gas-phase thermophysical properties as well as variable liquid-phase viscosities and latent heat of vaporization. Additional features of the model include internal liquid circulation with transient droplet heating, droplet surface regression due to vaporization, and droplet deceleration with respect to the free flow due to drag. The numerical calculation employs an iterative solution procedure that has been successfully used previously for an isolated all-liquid droplet. We found that the relative motion of the solid particle and the liquid-carrier fluid is very significant during the early stages of the simulation. In that respect, the fluid mechanics dominate the heat and mass transport phenomena involved, thus strongly suggesting a high possibility of secondary atomization as a result of the penetration of the solid particle through the gas/liquid interface.