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An investigation into predicting vortex ring state in rotary aircraft

Westbrook-Netherton, Oliver; Toomer, Chris


Oliver Westbrook-Netherton


Results from wind tunnel experiments and Computational Fluid Dynamic (CFD) simulations have been presented which suggest it may be possible to predict when a rotary aircraft will enter Vortex Ring State (VRS). Results suggest that the formation of a small, toroidal vortex which develops approximately 2.5 blade radiuses above the rotor plane of a model helicopter develops over time as the model helicopter descends into VRS. As the toroidal vortex develops, the lift the rotor is producing decreases over time until the toroidal vortex has reached the rotor plane of the model helicopter. Repeating the experiment using the same model at different wind tunnel and rotor speeds to cause it to descend into VRS produces the same results. Repeating the experiment using a propeller also produces the same results. CFD simulations show the formation of the toroidal vortex and development into VRS.


Westbrook-Netherton, O., & Toomer, C. (2014, July). An investigation into predicting vortex ring state in rotary aircraft. Paper presented at RAeS Applied Aerodynamics Conference, University of Bristol, Bristol, UK

Presentation Conference Type Conference Paper (unpublished)
Conference Name RAeS Applied Aerodynamics Conference
Conference Location University of Bristol, Bristol, UK
Start Date Jul 22, 2014
End Date Jul 24, 2014
Publication Date Jul 1, 2014
Peer Reviewed Not Peer Reviewed
Keywords rotary aircraft
Public URL
Additional Information Title of Conference or Conference Proceedings : RAeS Advanced Aero Concepts, Design and Operations