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The role of rotary motion on vortices in reverse flow

Published online by Cambridge University Press:  15 October 2019

Luke R. Smith Open the ORCID record for Luke R. Smith [Opens in a new window] ,
Yong Su Jung ,
James D. Baeder  and
Anya R. Jones Open the ORCID record for Anya R. Jones [Opens in a new window]
Luke R. Smith*
Affiliation:
Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA
Yong Su Jung
Affiliation:
Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA
James D. Baeder
Affiliation:
Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA
Anya R. Jones
Affiliation:
Department of Aerospace Engineering, University of Maryland, College Park, MD 20742, USA
*
†Email address for correspondence: [email protected]
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Abstract

The physics of a rotary wing in forward flight are highly complex, particularly when flow separation is involved. The purpose of this work is to assess the role of three-dimensional (3-D) vortex dynamics, with a focus on Coriolis forces, in the evolution of vortices in the reverse flow region of a rotating wing. High-fidelity numerical simulations were performed to recreate the flow about a representative rotating wing in forward flight. A vorticity transport analysis was performed to quantify and compare the magnitudes of 2-D flow physics, vortex tilting and Coriolis effects in the resulting flow fields. Three-dimensional vortex dynamics was found to have a very small impact on the growth and behaviour of vortices in the reverse flow region; in fact, the rate of vortex growth was successfully modelled using a simple 2-D vortex method. The small role of 3-D physics was attributed to the Coriolis and vortex tilting terms being approximately equal and opposite to one another. This ultimately lead to vortex behaviour that more closely resembled a surging wing as opposed to a conventional rotating wing, a feature unique to the reverse flow region.

JFM classification

Wakes/Jets: Separated flows Vortex Flows: Vortex shedding Vortex Flows: Vortex dynamics
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 880 , 10 December 2019 , pp. 723 - 742
Copyright
© 2019 Cambridge University Press 

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