Numerical Simulation of an Oscillating Cylinder at High Reynolds Number

• Published in: Volume 7: CFD and VIV
• Main Authors: MANDELLI, SIMONE, MUGGIASCA, SARA, MALAVASI, STEFANO
• Other Authors: Mandelli, Simone, Muggiasca, Sara, Malavasi, Stefano
• Format: Conference Object
• Language: English
• Published: 2013
• Subjects: Arctic
• Online Access: http://hdl.handle.net/11311/748375; https://doi.org/10.1115/OMAE2013-11362

In this work, we propose a numerical investigation of the main flow field characteristics around a free oscillating rigid circular cylinder that is immersed in a turbulent flow (Re≈5∙〖10〗^4). The cylinder is characterized by high value of mass ratio and mass damping (m^*=145; ξ=0.6÷1.14∙〖10〗^(-3);m^* ξ=0.1÷0.25). Then the numerical results are compared with previous experimental data obtained in the wind tunnel under very similar fluid dynamic conditions. There are few works in literature that consider both numerical and experimental results under these conditions. This is probably due to the experimental facilities limitations and the computational difficulties correlated to modeling the flow with high Reynolds number. With the aim of matching the experimental analysis, developed in the last years in the Politecnico di Milano Wind Tunnel on a suspended oscillating cylinder, with numerical results, we set-up a numerical URANS model through a CFD commercial code using a k-ω SST turbulence model in a 3D domain. The numerical setup is characterized by the use of the DFBI-Morphing (Dynamic Fluid Body Interaction) model that allows the modeling of the body motion in response to fluid forces treating the cylinder as a mass-damping-spring system by introducing spring and damping forces acting on it. A preliminary check of this numerical setup was provided by a benchmark involving a simple case of fixed cylinder at the same Reynolds number, where the movements of the cylinder were disabled. The numerical results of this case have been compared with experimental and numerical results reported in literature by means of Drag and Lift coefficients and Strouhal number at high Reynolds (Re≈5∙〖10〗^4). After that benchmark, the full setup has been checked by considering specific fluid dynamic conditions where the cylinder was out of the lock in region in which the oscillations of the cylinder are negligible. Finally we have investigated two points of the steady state oscillating response curve of the cylinder in the lock in ...