The immersed boundary method (IBM) is used for the simulations of the two-dimensional cases. The calculations are carried out on a Eulerian-Lagrangian grid using the finite difference method. The simulations are performed using two Reynolds numbers 100 and 200. The streamline and vorticity contours of the flow around the cylinders and force time histories are presented. | Journal of Science & Technology 130 (2018) 033-038 Numerical Investigation of the Viscous Incompressible Flow Around Two Circular Cylinders in Tandem Arrangement Phan Duc Huynh* Ho Chi Minh City University of Technology and Education No 1 Vo Van Ngan Street, Linh Chieu Ward, Thu Duc District, Ho Chi Minh City Received: December 25, 2016; Accepted: November 26, 2018 Abstract The shedding of vortices and flow interference between two circular cylinders in tandem arrangements are investigated numerically in this paper. The two values and of the ratio between the distance of two cylinders and the diameter of the cylinder were used. The immersed boundary method (IBM) is used for the simulations of the two-dimensional cases. The calculations are carried out on a Eulerian-Lagrangian grid using the finite difference method. The simulations are performed using two Reynolds numbers 100 and 200. The streamline and vorticity contours of the flow around the cylinders and force time histories are presented. The calculations are also compared to results obtained by other researchers. Numerical results show that the immersed boundary method can easily solve the viscous incompressible flow past single and two cylinders in a tandem arrangement. Keywords: Immersed boundary method, Circular cylinder, Tandem arrangement, Incompressible flow 1. Introduction force coefficients with the Reynolds number Re and with the center-to-center distance L. * The circular cylinders form the basic component of structures and machinery in the many areas of engineering, for example, cooling towers, heat exchange tubes, cooling systems for nuclear power plants, offshore structures, transmission cables, etc. These structures are immersed in either air or water flow, and therefore they experience flow-induced vibration. This vibration can lead to structural failure under severe conditions. To avoid these situations and to have better structural designs, it is necessary to understand the .