Simulation of unsteady three-dimensional flow around a square cylinder at moderate Reynolds numbers
(1999) In Physics of Fluids 11(2). p.288-306- Abstract
- Direct numerical simulations of two-dimensional (2D) and 3-D unsteady flow around a square cylinder for moderate Reynolds numbers (Re=150–500) are performed, employing an implicit fractional step method finite-volume code with second-order accuracy in space and time. The simulations, which are carried out with a blockage ratio of 5.6%, indicate a transition from 2-D to 3-D shedding flow between Re=150 and Re=200. Both spanwise instability modes, A and B, are present in the wake transitional process, similar to the flow around a circular cylinder. However, seemingly in contrast to a circular cylinder, the transitional flow around a square cylinder exhibits a phenomenon of distinct low-frequency force pulsations (Re=200–300). For 3-D... (More)
- Direct numerical simulations of two-dimensional (2D) and 3-D unsteady flow around a square cylinder for moderate Reynolds numbers (Re=150–500) are performed, employing an implicit fractional step method finite-volume code with second-order accuracy in space and time. The simulations, which are carried out with a blockage ratio of 5.6%, indicate a transition from 2-D to 3-D shedding flow between Re=150 and Re=200. Both spanwise instability modes, A and B, are present in the wake transitional process, similar to the flow around a circular cylinder. However, seemingly in contrast to a circular cylinder, the transitional flow around a square cylinder exhibits a phenomenon of distinct low-frequency force pulsations (Re=200–300). For 3-D simulations, the Strouhal number and the mean drag coefficient are in general agreement with existing experiments. Between Re=300 and 500, an increase in the spanwise coupling of fluctuating forces is indicated. The influence of the spanwise aspect ratio using periodic boundary conditions, a finer grid, and a finer time step is also investigated.
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https://lup.lub.lu.se/record/7ad5c9f4-d6aa-4d79-8aac-a213144ec32f
- author
- Sohankar, Ahmad ; Norberg, Christoffer LU and Davidson, Lars
- organization
- publishing date
- 1999
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physics of Fluids
- volume
- 11
- issue
- 2
- pages
- 288 - 306
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- scopus:0000928634
- ISSN
- 1070-6631
- DOI
- 10.1063/1.869879
- language
- English
- LU publication?
- yes
- id
- 7ad5c9f4-d6aa-4d79-8aac-a213144ec32f
- date added to LUP
- 2022-10-13 17:14:33
- date last changed
- 2022-11-06 04:04:51
@article{7ad5c9f4-d6aa-4d79-8aac-a213144ec32f, abstract = {{Direct numerical simulations of two-dimensional (2D) and 3-D unsteady flow around a square cylinder for moderate Reynolds numbers (Re=150–500) are performed, employing an implicit fractional step method finite-volume code with second-order accuracy in space and time. The simulations, which are carried out with a blockage ratio of 5.6%, indicate a transition from 2-D to 3-D shedding flow between Re=150 and Re=200. Both spanwise instability modes, A and B, are present in the wake transitional process, similar to the flow around a circular cylinder. However, seemingly in contrast to a circular cylinder, the transitional flow around a square cylinder exhibits a phenomenon of distinct low-frequency force pulsations (Re=200–300). For 3-D simulations, the Strouhal number and the mean drag coefficient are in general agreement with existing experiments. Between Re=300 and 500, an increase in the spanwise coupling of fluctuating forces is indicated. The influence of the spanwise aspect ratio using periodic boundary conditions, a finer grid, and a finer time step is also investigated.<br/>REFERENCES}}, author = {{Sohankar, Ahmad and Norberg, Christoffer and Davidson, Lars}}, issn = {{1070-6631}}, language = {{eng}}, number = {{2}}, pages = {{288--306}}, publisher = {{American Institute of Physics (AIP)}}, series = {{Physics of Fluids}}, title = {{Simulation of unsteady three-dimensional flow around a square cylinder at moderate Reynolds numbers}}, url = {{http://dx.doi.org/10.1063/1.869879}}, doi = {{10.1063/1.869879}}, volume = {{11}}, year = {{1999}}, }