New Approaches to Numerical Simulation of Two-Component Droplet Evaporation

摘要

In order to indicate the droplet evaporating process directly,a new evaporation model for the drying of a single solution droplet into a solid,dense particle is present,taking account of the changing of temperature gradient and concentration gradient.Simulations are made to achieve a more fundamental understanding of the coupled relationship of solvent percentage,droplet specific heat,saturated vapor pressure and solvent diffusion coefficient.According to the moving boundary problem,the numerical method of droplet evaporation is constructed by the mesh-reconstruction technology,and the visualization of the simulation results is realized by Matlab.Taking the evaporation process of water and ammonium nitrate solution for example,the transient variations of drop diameter,inner temperature gradient,inner solute concentration gradient are analyzed under different gas temperature and flow velocity.Model predictions are in good agreement with the experimental data,indicating that the model describes the most important physical phenomena of the evaporating process.