NUMERICAL DROPLET DISTRIBUTION FOR ETHANOL SPRAY WITH OPENFOAM
Helder Alves de Almeida Junior1; Roberto Ribeiro Schor1; Alysson Fernandes Teixeira1; Ramon Molina Valle1
1 Universidade Federal de Minas Gerais - UFMG
doi:10.20906/CPS/CON-2016-1596
Resumo
Internal combustion engines are thermal machines that convert chemical energy contained in a fuel into mechanical energy, using combustion. Because of their simplicity, ruggedness and high power/weight ratio, internal combustion engine has been responsible for supplying a significant portion of energy generation required for the daily life of our society. The new high-end concept of mixture formation for SI engine has been using a Direct Injection System, accordingly the fuel is delivered with high pressure into the combustion chamber on the compression stage. The use of atomizers to deliver fluids require that the drop size distribution must have a particular form with narrow, wide, few large drops, few small drops, among others for optimal operation. No fundamental mechanism or model enables a theory on particle-size distribution to be built, consequently, a wide variety of empirical models or equations have been proposed to characterize experimental particle-size distributions, such as the Rosin Rammler model. In order to understand and analyze the numerical modeling of these phenomena, this paper illustrates the review of two available methods for modeling drop size distributions in fuel spray: the empirical classical method and Rosin Rammler method. A numerical investigation was carried out using the capabilities of OpenFoam code to evaluate the characteristic form of the fluid in the spray. The results shown that both distributions are well implemented in the software, compared to the literature. The work demonstrate that the Rosin Rammler model better reproduce the Spray droplets distribution.
Palavras-chave: OpenFoam; Rosin Rammler ; Ethanol; Direct Injection ; Internal combustion engines