Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/43755
Title: Effects of large spanwise wavelength on the wake of a sinusoidal wavy cylinder
Authors: Lin, YF
Bai, HL
Alam, MM
Zhang, WG
Lam, K
Keywords: Force reduction/suppression
Large eddy simulation
Large spanwise wavelength
Sinusoidal wavy cylinder
Issue Date: 2016
Publisher: Academic Press
Source: Journal of fluids and structures, 2016, v. 61, p. 392-409 How to cite?
Journal: Journal of fluids and structures 
Abstract: The wake of a sinusoidal wavy cylinder with a large spanwise wavelength λ/Dm (=3.79-7.57) and a constant wave amplitude a/Dm=0.152, where Dm is the mean diameter of the cylinder, is investigated using three dimensional (3D) large eddy simulation (LES) at a subcritical Reynolds number Re=3×103, based on incoming free-stream velocity (U∞) and Dm. Attention is paid to assimilating the effects of λ/Dm on the cylinder wake, including vortex shedding frequency, spanwise vortex formation length, streamwise velocity distribution, flow separation angle, 3D vortex structure, and turbulent kinetic energy (TKE) distribution. Based on the predominant role of λ/Dm in the near wake modification, three regimes are identified, i.e., regime I at λ/Dm<6.0, regime II at λ/Dm≈6.0 and regime III at λ/Dm>6.0. A dramatic decrease in fluid forces is observed at λ/Dm=6.06, about 16% and 93% reduction in time-averaged drag and fluctuating lift, respectively, compared to those of a smooth cylinder. We identified, for the first time, an optimum λ/Dm (=6.06) for the wavy cylinder with relatively large λ/Dm (>3.5) in the subcritical flow regime. The underlying mechanisms of force reduction are discussed, including the flow characteristics at the three λ/Dm regimes. A comparison is also made between the results of λ/Dm effects on the near wakes of a circular and a square cylinder.
URI: http://hdl.handle.net/10397/43755
ISSN: 0889-9746
EISSN: 1095-8622
DOI: 10.1016/j.jfluidstructs.2015.12.004
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

2
Last Week
0
Last month
Citations as of Sep 10, 2017

WEB OF SCIENCETM
Citations

1
Last Week
0
Last month
Citations as of Sep 23, 2017

Page view(s)

24
Last Week
0
Last month
Checked on Sep 17, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.