Coupled thrust and vorticity dynamics during VRS

Savas, O., Green, R.B. and Caradonna, F.X. (2008) Coupled thrust and vorticity dynamics during VRS. In: AHS Specialists' Conference on Aeromechanics, San Francisco, USA, 23-25 Jan 2008,

Abstract

The focus is on the vortex ring state (VRS) observed at rapid descent rates. At VRS, the helical vortex filaments coming off the blades amalgamate around the rotor disk forming a vortex ring, which periodically detaches into the wake, causing extreme oscillations in thrust, with periods on the order of several tens of rotor revolutions. We discuss here the phase relation between the thrust cycle and vorticity distribution at the rotor disk. Maxima of the VRS thrust oscilla- tions correlate well with the maxima of circulation, enstrophy, and minima of enstrophy dispersion radius observed in the vicinity of the rotor disk.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Green, Dr Richard
• Authors: Savas, O., Green, R.B., and Caradonna, F.X.
• Subjects: T Technology > T Technology (General)
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Research Group: Low Speed Aerodynamics
• Copyright Holders: Copyright © 2008 American Helicopter Society
• First Published: First published in AHS Specialist's Conference on Aeromechanics
• Publisher Policy: Reproduced with permission of the publisher