Fast-Time Modeling of Ground Effects on Wake Vortex Transport and Decay

A fast-time model for wake vortex behavior prediction in ground proximity is presented. This model takes into account the combined effects of ground proximity and wind (both crosswind and headwind components) on the wake vortex transport and decay. It aims to mimic the whole flow using a limited set of vortex particles to model both the primary two-vortex system and the ground-generated secondary vorticity. A redistribution of the vortex particles is also included in the model to limit the number of used particles and hence, guarantee a high computational efficiency. The model is integrated in the deterministic wake vortex model, which is a software that predicts, also in real-time, the temporal evolution of the wake vortices generated by a given aircraft evolving in given ambient meteorological conditions. The new ground effect model capacity is assessed using data from a measurement campaign and from large-eddy simulations. It is found that the model is able to reproduce the wake vortex behavior (both for transport and decay) for the most relevant times required for air traffic management applications.