Middle-East Journal of Scientific Research 15 (1): 08-13, 2013 ISSN 1990-9233 © IDOSI Publications, 2013 DOI: 10.5829/idosi.mejsr.2013.15.1.2628 Corresponding Author: M. Salari, Department of Mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. 8 Investigation of Flow Around a Confined Elliptical Cylinder Using the Lattice Boltzmann Method M. Taeibi-Rahni, V. Esfahanian and M. Salari 1,2 3 2 Department of Aerospace Engineering, Sharif University of Technology, Tehran, Iran 1 Department of Mechanical and Aerospace Engineering, 2 Science and Research Branch, Islamic Azad University, Tehran, Iran School of Mechanical Engineering, University of Tehran, College of Engineering, Tehran, Iran 3 Abstract: This paper deals with the investigation of the laminar flow past an elliptical cylinder confined in a channel. In this paper, the Lattice Boltzmann (LB) method is used to simulate flow in two dimensions. The present LB method with the used boundary conditions is validated in simulations of the incompressible flow past a circular cylinder. The simulations are carried out in a range of condition, 0 90 (angle of incidence), 5 Re 100, (Reynolds number) for AR=0.25,0.5 (aspect ratio). The effects of those parameters on the drag and lift coefficients and other flow characteristics of the cylinder are examined in detail. The results demonstrate that the drag and lift coefficients increase with the increase of . It is seen that vortex shedding is not occurred at high Reynolds numbers at =0. Key words: Elliptical cylinder Lattice-Boltzmann method Strouhal number Drag and lift coefficients Laminar flow INTRODUCTION an unconfined elliptic cylinder at various angles of The flow past cylinders has extensive applications flow over an elliptical cylinder at Reynolds numbers of in engineering problems such as cooling towers, heat 100,500 and 1000. His solution was based on a numerical exchangers, chimney stacks, nuclear reactors and integration of the Helmholtz vorticity transport equation offshore structures. Consequently, a large number of with the stream function equation. Chanada [9] researchers have studied this kind of flow. Most of investigated the unsteady two dimensional flow of these studies were concerned with the circular cylinders viscous fluid normal to a thin elliptic cylinder using a [1-4]. In contrast, there are few researches that study vorticity-stream function formulation of the full the flow over an elliptical cylinder. Imai [5] studied the Navier-Stocks equations. Choi and Lee [10] Studied uniform flow past an elliptic cylinder at an arbitrary angle experimentally the flow characteristics around an elliptic of incidence for the thickness ratio t=0-1 and the cylinder with axis ratio of AR=2 located near a flat plate Reynolds numbers Re = 0.1,1. He obtained analytical experimentally. They considered various angles of expressions for the lift and drag coefficients. Patel [6] attack of the cylinder in order to study the interaction investigated the flow around an impulsively started between the cylinder wake and the boundary layer. elliptic cylinder at various angles of incidence (0, 30, 45 Kocabiyik and D’Alessio [11] presented the numerical and 90°) at Re = 200 by solving the Navier-Stokes calculations of the flow around an inclined elliptic equations numerically. He observed a Kármán vortex cylinder oscillating in-line with the incident steady street at 30 and 45 incidence for Re=60,200. Park et al. flow at Reynolds number Re=1000 and axis ratio of 0.5. [7] studied the details of the laminar unsteady flows past They investigated the effects of the angle of inclination incidence. They distinguished five regimes for flow characteristics. Badr [8] solved the oscillating viscous