Modeling Fuel Injection in Gas Turbines Using the Meshless Smoothed Particle Hydrodynamics Method

For predicting primary atomization a numerical code has been developed based on the Lagrangian Smoothed Particle Hydrodynamics (SPH) method. The advantage of this approach is the inherent interface advection. In contrast to commonly used grid based methods such as the Volume of Fluid (VoF) or Level Set method there is no need for costly and approximative interface tracking or reconstruction techniques which are required to avoid interface diffusion. It has been demonstrated by various test cases that the SPH method is capable to correctly predict single — as well as multiphase flows including the effect of surface tension. The goal of this work is to further develop the methodology with the intention to simulate primary atomization within airblast atomizers of jet engines. The authors present two test cases relevant for the simulation of primary atomization. The shear-driven deformation of a fuel droplet in a gaseous flow has been investigated and compared to data from literature. Moreover, the liquid film disintegration at the trailing edge of a planar prefilming airblast atomizer has been studied. The geometry has been derived from an existing test rig, where extensive experimental data have been acquired. Resulting droplet sizes and shear-off frequencies for different geometrical setups have been analyzed and compared to the experiment. The results reveal the promising performance of this new method for predicting primary atomization.