Effect of Ground Obstacle Separation Distance on Wake Vortex Dissipation C.H. John Wang ∗ and D. Zhao † Nanyang Technol Univ, Sch Mech & Aerosp Engn, Singapore 639798, Singapore and J. Schl¨ uter ‡ Deakin University, Melbourne, Australia The implementation of plate type ground obstacle for wake vortex dissipation in the vicinity of runway has been investigated in previous studies by our collaborators at the German Aerospace Institute (DLR) though both experimental work and Large Eddy Simulation studies. We have expended on the concept by investigating the impact of different plate configurations, in terms of shape from top-down view, on the rate of dissipation as well as the propagation speed of the instability introduced by the obstacle. Parameter study of “Plate Line” obstacle were carried out using Large Eddy Simulation with OpenFOAM solver, with emphasis on the relative lateral position between the initial vortex and the “Plate” obsta- cle. The test section dimensions and the initial vortex parameters from DLR’s Wasser Schleppkanal G¨ottingen experiment was used in the sim- ulation to isolate the effect of obstacle from the influence of background turbulence and cross wind. I. Introduction The trajectory of wake vortex near the vicinity of runway is bounded by the presence of the ground and would frequent rebound back into the flight path of subsequent aircraft. As a result, the majority of wake encounter reported in the NTSB, FAA, and NASA database 1 occurs during landing and approach phase of the flight. The hazard of wake encounter could be exacerbated by the presence of crosswind such that the upwind vortex hovers over the runway and above the influence of ground induced instability; the chance * Research Fellow, Air Traffic Management Research Institute † Assistant Professor, Corresponding Author, E-mail address: zhaodan@ntu.edu.sg ‡ Senior Lecturer, School of Engineering 1 of 10