Analysis of Flow Pattern with Low Reynolds Number around Different Shapes of Bridge Piers, and Determination of Hydrodynamic Forces, applying Open Foam Software

Document Type : Regular Paper


1 Assistant Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran

2 Graduated MSc. student, Faculty of Civil Engineering, Semnan University, Semnan, Iran

3 Professor, Faculty of Civil Engineering, Semnan University, Semnan, Iran


In many cases, a set of obstacles, such as bridge piers and abutments, are located in the river waterway. Bridge piers disrupt the river’s normal flow, and the created turbulence and disturbance causes diversion of flow lines and creates rotational flow. Geometric shape and position of the piers with respect to flow direction and also the number of piers and their spacing are effective in changing the river-flow conditions, such as the formation of vortices, their breakdown and hydrodynamic forces exerted on the piers. This article has been performed by applying the two-dimensional, open-source, OpenFOAM software. For this purpose, after selecting the grid size in GAMBIT software, different pier shapes were examined , considering different Reynolds numbers, and formation of the flow pattern, Strouhal number, vortex magnitude, and drag and lift coefficients for each pier shape were specified. Results for three different pier shapes indicated that in Reynolds number of 200, the highest drag coefficient (1.82) and maximum flow velocity (1.55 m/s) correlated to the square pier. The lowest drag coefficient (0.46) was calculated for the rectangular pier (having a semi-circular edge on one side and a sharp-nose edge on the other side) when the flow collides with the semi-circular edge. The least drag and lift forces are exerted to the rectangular pier, as compared to other pier shapes. The lowest lift coefficient (0.012) was obtained for a rectangular pier. On the other hand, the position of the sharp-nosed edge in the wake region caused the vortex shedding to occur at a greater distance from the pier.


Main Subjects

[1] Fredsoe, J., Hansen, E.A. (1987). “Lift forces on pipelines in steady flow.’’ Journal of Waterway, Port, Costal and Ocean Engineering, ASCE, Vol. 113, pp. 139-155.
[2] Park, J., Kwon, K., Choi, H. (1998). “Numerical solutions of flow past a circular cylinder at Reynolds number up to 160.’’ KSME International Journal, Vol. 12, No 6, pp. 1200-1205.
[3] Saha, A.K., Biswas, G., Muralidhar, K. (2003). “Three-dimensional study of flow past a square cylinder at low Reynolds number.’’ International Journal of Heat and Fluid Flow, Vol. 24, pp. 54-66.
[4] Zhao, M., Cheng, L., Teng, B., Liang, D. (2005). “Numerical simulation of viscous flow past two circular cylinders of different diameters.’’ Applied Ocean Research, Vol. 27, pp. 39-55.
[5] Zhang, L.T., Gay, M. (2008). “Imposing rigidity constraints on immersed objects in unsteady fluid flows.’’ Computational Mechanics, Vol. 42, pp. 357-370.
[6] Sami Akoz, M., Salih Kirkgoz, M. (2009). “Numerical and experimental analysis of the flow around a horizontal wall-mounted circular cylinder.’’ Transaction of the Canadian Society for Mechanical Engineering, Vol. 33, pp. 189-215.
[7] Lee, T., Kim, Y., Chang, Y., Choi, J. (2009). “Determination of drag and lift forces around a circular cylinder by using a modified immersed finite-element method.’’ Journal of Korean Physical Society, Vol. 54, No. 3, pp. 1068-1071.
[8] Gera, B., Pavan, K.S., Singh, R.K. (2010). “CFD analysis of 2D unsteady flow around a square cylinder.’’ International Journal of Applied Engineering Research, Vol. 1, No. 3, pp. 602-610.
[9] Omid Naeini, S.T., Fazli, M. (2010). “Numerical modeling and physical observation of the effect of shape of bridge piers on the imposed dynamic forces.’’ Civil Engineering Infrastructures, Vol. 44, No. 5, pp. 741-751. (In Persian).
[10] Bai, H., Li, J. (2011). “Numerical simulation of flow over a circular cylinder at low Reynolds number.’’ Advanced Materials Research, Vols. 255-260, pp. 942-946.
 [11] Keramati Farhoud, R., Amiralaie, S., Jabbari, G.H., Amiralaie, S. (2012). “Numerical study of unsteady laminar flow around a circular cylinder.’’ Journal of Civil Engineering and Urbanism, Vol. 2, Issue 2, pp. 63-67.
[12] Vikram, C.K., Krishne Gowda, Y.T., Ravindra, H.V. (2014). “Analysis by CFD for flow past circular and square cylinder.’’ International Journal of Innovations in Engineering and Technology, Vol. 4, Issue 3, pp. 72-76.
[13] The Open Source CFD Toolbox OpenFOAM. (2010). GNU Free Documentation License.
[14] Sarreshtedari, A., Varedi S.R. (2011). “Fluid flow modeling and heat transfer by OpenFOAM software.” Shahrood University of Technology, Shahrood, Iran.
[15] Sumer, B.M., Fredsoe, J. (1997). “Hydrodynamics around cylindrical structures.’’ World Scientific Publication Co., Ltd., Singapore.
[16] Roshko, A. (1961). “Experiments on the flow past a circular cylinder at very high Reynolds number.” Journal of Fluid Mechanics, Vol. 10, pp. 345-356.
[17] Schewe, G. (1983). “On the force fluctuations acting on a circular cylinder in cross flow from subcritical up to transcritical Reynolds numbers.’’ Journal of Fluid Mechanics, Vol. 133, pp. 265-285.
Volume 6, Issue 1 - Serial Number 11
February 2018
Pages 34-48
  • Receive Date: 17 July 2016
  • Revise Date: 17 April 2017
  • Accept Date: 24 May 2017
  • First Publish Date: 01 February 2018