Taha Khademinezhad - Departmant of Mechanical, Materials and Aerospace Engineering, Illinois Institute of Technology, IL, Chicago
Pouyan Talebizadeh - Departmant of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
Hassan Rahimzadeh - Departmant of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran

The aim of this paper is to investigate the vortex structures as well as lift and drag coefficients in flows around a square cylinder in compare with circular cylinder using the commercial Fluent software. Furthermore, the effect of the Reynolds number on the formation of the vortex structures as well as velocity field is investigated and compared for both circular and square cylinder at different times. The results show the good agreements of the drag coefficient, lift coefficient and the Strouhal number with the previous studies. Moreover, the results show that the lift coefficient is increased strongly when the Reynolds number increases; however, the drag coefficient and the Strohoul number do not change noticeably. Furthermore, increasing the Reynolds number causes that the fluctuations in lift and drag coefficients start at an earlier time.

Computational Fluid Dynamics (CFD), Square cylinder, Drag coefficient, lift coefficient, Strouhal number