Numerical study of the rounded corners effect on flow past a square cylinder
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 5 May 2015
Abstract
Purpose
The purpose of this paper is to numerically investigate the influence of corner radius on flow past a square cylinder at a Reynolds number 500.
Design/methodology/approach
Six models were studied, for R/D=0 (square cylinder), 0.1, 0.2, 0.3, 0.4, and 0.5 (circular cylinder), where R is the corner radius and D is the characteristic dimension of the body. The transient two-dimensional (2D) laminar and large eddy simulations (LES) models were employed using finite volume code. The Strouhal number, mean drag coefficient (CD), and root mean square (RMS) value of lift coefficient (CL,RMS), for different R/D values, were computed and compared with experimental and other numerical results.
Findings
The computational results showed good agreement with previously published results for a Reynolds number, Re=500. It was found that the corner effect on a square cylinder greatly influences the flow characteristics around the cylinder. Results indicate that, as the corner radius ratio, R/D, increases, the Strouhal number increases rapidly for R/D=0-0.2, and then gradually rises between R/D=0.2 and 0.5. The minimum values of the mean drag coefficient and the RMS value of lift coefficient were found around R/D=0.2, which is verified by the time averaged streamwise velocity deficit profile.
Originality/value
On the basis of the numerical results, it is concluded that rounded corners on a square cylinder are useful in reducing the drag and lift forces generated behind a cylinder. Finally, it is suggested that with a rounded corner ratio of around R/D=0.2, the drag and oscillation of the cylinder can be greatly reduced, as compared to circular and square cylinders.
Keywords
Acknowledgements
This work is supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2010-0025260).
Citation
Miran, S. and Sohn, C.H. (2015), "Numerical study of the rounded corners effect on flow past a square cylinder", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 25 No. 4, pp. 686-702. https://doi.org/10.1108/HFF-12-2013-0339
Publisher
:Emerald Group Publishing Limited
Copyright © 2015, Emerald Group Publishing Limited