An investigation into predicting vortex ring state in rotary aircraft

Westbrook-Netherton, Oliver; Toomer, Chris

Abstract

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.

Citation

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

• Presentation Conference Type: Conference Paper (unpublished)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• Peer Reviewed: Not Peer Reviewed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