Coupled thrust and vorticity dynamics during vortex ring state

Savas, O., Green, R.B. and Caradonna, F.X. (2009) Coupled thrust and vorticity dynamics during vortex ring state. Journal of the American Helicopter Society, 54, 022001. (doi:10.4050/JAHS.54.022001)

Savas, O., Green, R.B. and Caradonna, F.X. (2009) Coupled thrust and vorticity dynamics during vortex ring state. Journal of the American Helicopter Society, 54, 022001. (doi:10.4050/JAHS.54.022001)

Full text not currently available from Enlighten.

Abstract

This paper focuses on the vortex ring state (VRS) that is observed in the flow around a rotor during rapid descent. In VRS, the vortex filaments trailed off the blades coalesce around the rotor disk. This vortex ring detaches into the wake periodically, causing extreme oscillations in thrust, with periods on the order of several tens of rotor revolutions. The phase relation between the thrust cycle and vorticity distribution at the rotor disk is discussed. Maxima of the VRS thrust oscillations correlate well with the maxima of circulation, enstrophy, and minima of enstrophy dispersion radius observed in the vicinity of the rotor disk.

Item Type:Articles
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 > TJ Mechanical engineering and machinery
Q Science > QC Physics
College/School:College of Science and Engineering > School of Engineering > Aerospace Sciences
Journal Name:Journal of the American Helicopter Society
Publisher:American Helicopter Society
ISSN:0002-8711

University Staff: Request a correction | Enlighten Editors: Update this record