Simulation of wake vortex detection with airborne Doppler lidar

A simulation approach is used to demonstrate that an airborne, forward-looking lidar can detect trailing wake vortices generated by a leading aircraft. Computational fluid dynamics techniques are used to generated flowfields containing wake vortices. These flowfields are applied to a Doppler lidar simulation model. The simulated geometry has the forward-looking lidar mounted on a following aircraft, whereas the wake vortices are generated by a leading aircraft. In such a configuration, it is not possible to directly detect the strong rotational velocity components of a wake vortex with a Doppler system; detection relies on the presence of induced axial velocity signatures. We demonstrate that axial flows are induced as the vortices evolve, and that these axial flows can be detected with a Doppler lidar system.