Analysis of pollutant dispersion of a DHEP and LARW aircraft design using high-fidelity simulations

The increase in air traffic and its environmental impact necessitates an assessment of the potential health risks posed by aircraft pollutants to the civil population residing near airports. Wingtip vortices, one of the most prominent wake structures, play a crucial role in the dispersion of pollutants generated by aircraft. These vortices can persist for several minutes and travel hundreds of meters before decaying.Simultaneously, the growing need to reduce pollutant emissions and noise has driven the exploration of innovative technologies such as Distributed Hybrid Electric Propulsion (DHEP) systems and Large Aspect Ratio Wings (LARW). Within this context, the European INDIGO project—a consortium of ten research and scientific institutions—aims to investigate the application of these technologies in mid-range aircraft operations and assess their impact on airport vicinities.The complexity of pollutant dispersion, combined with the limited available data —particularly when applying DHEP and LARW technologies— necessitates the use of Computational Fluid Dynamics (CFD) as a fundamental tool. However, accurately modeling vortical structures presents significant challenges due to the high computational demands. These arise from the large domain sizes required to predict wakes and the broad range of spatial and temporal scales necessary to capture the various phasesof vortex decay. Furthermore, the method used to generate these vortices is a critical component of the modeling strategy, as it can influence subsequent wake dynamics and ultimately affect the accuracy of pollutant dispersion predictions in the near field of the aircraft. Among the available methods in the literature, the vortex sheet method—where the reactions of lift and drag forces on the air are imposed—stands out for its accuracy and its ability to model all stages of vortex evolution, includingthe vortex roll-up process. The objective of this study is twofold: first, to validate the simulation results of vortex evolution using a reference aircraft configuration for which numerical data is available, and second, to extend this methodology to analyze pollutant dispersion for the initial INDIGO aircraft design (without propellers)-incorporating LARW design-, using the vortex method. The aerodynamic simulations are performed within the framework of large-eddy simulations considering real force distributions and transporting a generic scalar as a surrogate of chemical pollutant.