2019_JWE.pdf (11.47 MB)
Low-frequency wake dynamics for a square-back vehicle with side trailing edge tapers
journal contribution
posted on 2019-01-10, 13:46 authored by Giancarlo Pavia, Martin Passmore, Max VarneyIn this paper, the effects of side trailing edge tapering on the wake of a simplified square-back vehicle are investigated. The tapered
surfaces are reported to trigger a switch from a laterally asymmetric bi-stable wake to a vertically asymmetric stable wake. The
wake structure reported in the literature for lateral symmetry breaking states is seen to rotate by 90◦
as the angle of the tapered
surfaces φs
is increased. A 6% drag reduction over the simple square-back case is reported for 6◦ < φs < 12◦
. This gain is found
to be the result of the stretching of the circular vortex responsible for the suction zone visible in any symmetry breaking state. A
downwash dominated wake is observed in these conditions. The sensitivity of such a wake to small variations of the model pitch
angle (for φs = 12◦
) is also assessed. As the pitch angle α is reduced from 0◦
to −2
◦
, the time averaged wake is reported to switch
from a downwash dominated topology to an upwash dominated topology. A strengthening of the long-time instability is observed
when the symmetry in the vertical direction is recovered and is accompanied with a 4.9% reduction in base drag over the same
model tested at α = 0
Funding
The authors would like to thank Jaguar Land Rover for their financial support.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
Journal of Wind Engineering and Industrial AerodynamicsVolume
184Pages
417 - 435Citation
PAVIA, G., PASSMORE, M.A. and VARNEY, M., 2019. Low-frequency wake dynamics for a square-back vehicle with side trailing edge tapers. Journal of Wind Engineering and Industrial Aerodynamics, 184 pp. 417 - 435.Publisher
© Elsevier BVVersion
- AM (Accepted Manuscript)
Publisher statement
This paper was accepted for publication in the journal Journal of Wind Engineering and Industrial Aerodynamics and the definitive published version is available at https://doi.org/10.1016/j.jweia.2018.12.009Acceptance date
2018-12-14Publication date
2018-12-20Copyright date
2019ISSN
0167-6105Publisher version
Language
- en