Turbulent flows past a cylinder is one of the most intensively investigated problem in fluid mechanics. The staggered shed vortices in the wake region exert oscillatory forces to the cylinder, and consequently excite the so called vortex-induced vibrations (VIV). Prediction and suppression of VIV are of special interest to the offshore industry because the cylinder represents a vast number of structural components in the offshore hydrocarbon exploitation.
Experimental measurement of the flow field past a cylinder is essential to understand the physical nature of the problem. Particularly the time-resolved Particle Image Velocimetry (PIV) technique is often adopted to not only qualitatively visualize the flow, but also to quantitatively measure the unsteady velocity field. In this paper, the flow around a cylinder inside the flume at UT's Fluid Mechanics and Hydraulics Lab, is measured using the PIV technique. The velocity histories at an array of selected points are recorded and analyzed as well. The turbulence intensity of the experimental facility in the absence of the cylinder is also determined.
The measured data are then correlated with the results from Computational Fluid Dynamics (CFD). Reynolds Averaged Navier-Stokes (RANS) simulation and Large Eddy Simulation (LES) are both performed. In RANS, the two-equation − shear-stress transport (SST) eddy viscosity model is applied. Meanwhile the LES is carried out in 3D.
The comparisons between experimental data and numerical results, presented in this paper, provide valuable insight in regards to the performance of the CFD methods in predicting VIV on cylinders.
