Numerical Prediction of Dispersion and Evaporation of Liquid Sprays in Gases Flowing at all Speeds

Abstract

This work is concerned with the formulation, implementation, and testing of an all-speed numerical procedure for the simulation of turbulent dispersion and evaporation of droplets. The pressure-based method is formulated, for both the discrete and continuous phases, within a Eulerian framework following a finite-volume approach and is equally applicable in the subsonic and supersonic regimes. The two-equation k −  ε turbulence model is used to estimate turbulence in the gas phase with modifications to account for compressibility at high speeds, while an algebraic model is employed to predict turbulence in the discrete phase. Two configurations involving streamwise and cross-stream injection are investigated, and solutions for evaporation and mixing of droplets sprayed into subsonic and supersonic streams are generated over a wide range of operating conditions. Results, displayed in the form of velocity vector fields and contour plots, reveal the degree of penetration of the injected droplet into the gas phase, and the rate of evaporation as a function of inlet gas temperature, inlet droplet temperature, and/or length of the domain.

The support provided by the Lebanese National Council for Scientific Research (LNCSR) through Grants 113040-022142 and 022129 is gratefully acknowledged.