CFD of flow around a cylinder at low Re number

U velocity contours
Iso vorticity, Re=1000

PhD student: Lixia Qu
Supervisor: Lars Davidson
Co-supervisor: Christoffer Norberg
Co-supervisor: Shia-Hui Peng
Cooperation: Prof. Wang Fujun, College of Water Conservancy & Civil Engineering, China Agricultural University
Sponsors: China Scholarship Council
Publications: [1]
Start of project: September 2010
End of project: -

Circular cylinder is well known as one of the most typical example of bluff bodies. The flow past a circular cylinder is one of the most frequently investigated flow configurations in fluid mechanic research as well. It includes complex phenomena such as vortex shedding, separation and reattachment. Its fundamental importance makes it useful for gaining knowledge of aerodynamic design and control.

So far, a vast amount of authors have reported on the variation of the lift-related coefficients with Reynolds number. From previous measurements and numerical simulations, it has been indicated that there is a sharp decrease in the RMS lift coefficient, CLp, between Re=200 and Re=1000, whereas the Strouhal, St, number increases only slightly, about 5%. The physical mechanisms responsible for this behavior in CLp and St are probably related to the intrinsic three-dimensional flow features; they will be further studied in the present project.

DNS is used to investigate the fluctuating forces acting on a circular cylinder at Re=50~1000, using CALC. For Reynolds number lower than 200, 2D simulations are carried out for evaluating the numerical method regarding to domain size, mesh density, time step, and so on.

In 3D numerical simulations, the Reynolds number is varied between from 200 to 1000. The main objective of this work is to study the relation between fluctuating forces and flow structures in the near wake region, as well as the relationship bwtween Reynolds number and three-dimensional instability in the separated region. Moreover, the correlation between the three-dimensional features of the separation and the three-dimensional wake structures is of great interest, especially within the range of Re=200~1000.

Iso vorticity at Re=500

Iso vorticity at Re=500




  1. L. Qu, Ch. Norberg, L. Davidson, S.-H. Peng, F. Wang
    "Quantitative numerical analysis of flow past a circular cylinder at Reynolds number between 50 and 200". Journal of Fluids and Structures Vol. 39, pp. 347-370, 2013
    Get article at publisher's www page
    View PDF file of manuscript

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Ingalena Ljungström