Numerical and experimental analysis of a gasoline fuel spray.

Calculations of number densities of inertial droplets in complex flows are encountered in modelling of numerous engineering and environmental phenomena, including the processes in internal combustion engines and air pollution [1, 2]. Traditionally, these calculations have been performed using either the Eulerian approach or Lagrangian approach based on the direct calculation of droplet trajectories in each computational cell [3]. An alternative method suggested by Osiptsov [4], also referred to as the fully Lagrangian method, is based on the droplet continuity equation in the Lagrangian form and predicts droplet number densities along pathlines by solving the equations for the components of the Jacobi matrix of the Eulerian-Lagrangian transformation. The method allows us to deal with regions of high number density gradients and intersections of droplet trajectories. Also, it significantly decreases the computational requirements in comparison with the conventional Lagrangian approach [5]. In this work the results of implementation of the fully Lagrangian approach into commercial CFD code ANSYS Fluent are discussed. A new methodology of the numerical analysis of the results of experimental observations of a gasoline spray at representative fuel injection conditions is suggested. Preliminary results of comparison between the predictions of the customized version of ANSYS Fluent, with the fully Lagrangian model implemented into it, and experimental data are presented. Heating and evaporation of droplets is not considered [6].