Unsteady characteristics of inlet vortices

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22 Citations (Scopus)

Abstract

An experimental study of the unsteady characteristics of inlet vortices has been conducted using a high-frame rate digital particle image velocimetry system. The results revealed the formation of a pair of counter-rotating inlet vortices for the no-wind configuration and one single inlet vortex when there was crosswind. In all measurement planes, from near the ground to the inlet, evidence of vortex meandering with quasi-periodicity was found. The vortex meander is dominant in the direction of the crosswind, and its amplitude increases with crosswind velocity. The proper orthogonal decomposition analysis of the instantaneous velocity field suggested that the most energetic mode was a helical displacement wave, corresponding to the first helical mode. Similarities with the meandering of the trailing vortices from wings were noted. The present results also suggest that the unsteady characteristics of the focus of separation formed on the ground might be responsible for the unsteady nature of the inlet vortex. © 2012 Springer-Verlag.
LanguageEnglish
Pages1015-1032
Number of pages18
JournalExperiments in Fluids
Volume53
Issue number4
Early online date4 Jul 2012
DOIs
StatusPublished - 1 Oct 2012

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Vortex flow
vortices
Intake systems
meanders
particle image velocimetry
wings
Velocity measurement
periodic variations
counters
velocity distribution
Decomposition
decomposition
configurations

Cite this

Unsteady characteristics of inlet vortices. / Wang, Zhijin; Gursul, I.

In: Experiments in Fluids, Vol. 53, No. 4, 01.10.2012, p. 1015-1032.

Research output: Contribution to journalArticle

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