Engine Position Effects on Contrail Evolution for a Realistic Aircraft Configuration

This study investigates the influence of representative engine positions on contrail evolution during the vortex and dissipation regimes, using three-dimensional simulations of a realistic aircraft geometry. Large-eddy simulations are employed, coupled with an Eulerian microphysical bulk model, and initialized using fields obtained from prior Reynolds-averaged Navier–Stokes simulations. This approach enables a consistent transition from near-field jet–vortex interactions to far-field wake dynamics. Three engine placements are examined under two atmospheric stratification and two relative humidity conditions. The results reveal that engine position influences the onset and evolution of vortex instabilities, alters the descent of the vortex pair, and leads to slight changes in the distribution of particles within the wake. Despite these aerodynamic differences, the microphysical properties of the contrails tend to converge over time for the parameters and configurations covered in this study. From a broader perspective, engine placement strongly influences initial contrail formation and early vortex-regime dynamics. At later stages, these differences largely disappear, as vortex dynamics and atmospheric conditions dominate over the initial dilution changes induced by engine position.