A new model for turbulent flows with large density fluctuations : application to liquid atomization
Résumé
Based on the original modeling proposal of Borghi and coworkers (A. Vallet, A. A. Burluka, and R. Borghi, Atomization and Sprays, vol. 11, pp. 619-642, 2001), a new model for atomization, focused on the description of the primary breakup, has been developed. For high injection velocities, the dense zone located just at the injector exit is generally not well described because of the strong interactions between complex phenomena. The classical Lagrangian approach that considers individual liquid droplets or blobs is not a satisfactory representation for such complex liquid flow topologies with liquid core ligaments and eventually droplets. Here, a more global approach is used, with liquid and gas considered as two species of a unique turbulent flow. Therefore, the initial liquid dispersion is given by a turbulent liquid mass flux. The purpose of this work is first to evaluate the usual models for this turbulent liquid flux and then to modify them for the specific turbulent flow with a very high density ratio considered here.
