Estudo numérico de jato líquido em escoamento cruzado usando uma abordagem híbrida

Abstract

The main goal of this dissertation is to present a proper methodology for numerical solution of spray formation in liquid jet in crossflow configuration, by means of a hybrid approach. Hybrid approach is a mixture of Euler-Euler and Euler-Lagrange approaches to solve a specific problem. From the stand point of the objectives of the dissertation, the VOF method was implemented in the unstructured grid code UNSCYFL3D, in which Euler-Lagrange structure had been already implemented. Numerical verification and validation for VOF method showed results according to the data from literature. Two primary breakup coefficients, two secondary breakup models and the effects of two-way coupling with droplet-to-droplet collisions were systematically evaluated, in order to establish the most suitable methodology to solve liquid jet in crossflow in the regimes of the studied cases. Numerical results presented good agreement with the experimental ones, related to liquid jet topology, spray formation, mean diameter of droplets, mass fraction distribution and droplet velocity. Considering the most difficult feature to be obtained experimentally, the primary coefficient Cb = 3.44 and the AB-TAB secondary breakup model showed the best agreement with the experimental results. Numerical results using two-way coupling with droplet-to-droplet collision presented negligible differences related to simulations using one-way coupling.