A comparative study of numerical models for Eulerian-Lagrangian simulations of turbulent evaporating sprays

摘要

The paper comparatively assesses the computational performance of a selected number of theoretical and semi-empirical liquid droplet evaporation models that focus on thermodynamic non-equilibrium effects, physical property estimation methods and convective and blowing effect corrections for the calculation of the heat and mass transfer rates. Three different test cases are examined in order to establish the most appropriate model, in terms of both physical accuracy and numerical efficiency for implementation in two-phase CFD spray simulations. The considered cases span from a single, isolated droplet, evaporating in a convective environment, to a fully turbulent, evaporating, hollow cone spray; for the latter case, an in-house Eulerian-Lagrangian CFD code is used. Predictions are validated against experimental data for all test cases and the most promising model is established on the basis of accuracy and CPU time requirements. As a result, the "infinite conductivity" equilibrium droplet evaporation model, combined with an analytic expression for the convective and blowing effect correction can be proposed as most appropriate for CFD spray applications.