INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2001; 35: 763–784 Computational modelling of flow around a circular cylinder in sub-critical flow regime with various turbulence models M. Tutar a, * ,1 and A. E. Holdø b a Makine Muhendisligi Bolumu, Mersin Uniersitesi, Ciftlikkoy, Mersin, Turkey b Aeronautical, Ciil and Mechanical Engineering Department, Uniersity of Hertfordshire, Hatfield, U.K. SUMMARY The numerical simulation of transitional flow around a two-dimensional stationary circular cylinder is presented using two groups of turbulence models in a sub-critical flow regime. In the first group, enhanced two-equation turbulence models based on the eddy viscosity concept are used. They include the non-linear k –  model with extended models, such as renormalization group (RNG) and the anisotropic model. In the second group, flow simulation is carried out using the large eddy simulation (LES) method, which is based on a standard sub-grid scale (SGS) model with a near-wall approach. This near-wall model, without using the ‘law of wall’, is achieved in a finite element code. The numerical results extracted from these simulations are compared with each other and with the experimental data in order to determine the relative performance of these turbulence models and to find the best model for the flow of interest. Although most of the LES simulations have been previously carried out using finite volume methods, results from using the present model show that the finite element method (FEM) can also be used with confidence. Copyright © 2001 John Wiley & Sons, Ltd. KEY WORDS: circular cylinder; finite element method; k –  based turbulence models; LES method; transitional flow 1. INTRODUCTION One of the classical problems in fluid mechanics is the determination of the flow field around a bluff body represented by a circular or rectangular cylinder. This is of great interest in many engineering applications, such as hydrodynamic loading on ocean marine piles and offshore platform risers and support legs. The early experiments [1,2] emphasized the effect of turbulence for the cylinder flow problem with an increase in Reynolds number. The first * Correspondence to: Makine Muhendisligi Bolumu, Mersin Universitesi, Ciftlikkoy, 33160 Mersin, Turkey. Tel.: +90 324 3610001; fax: +90 324 3610032. 1 E-mail: m.tutar@mersin.edu.tr Copyright © 2001 John Wiley & Sons, Ltd. Receied Noember 1999 Reised June 2000