Abstract
Numerical simulations are studied for a circular cylinder undergoing Flow-Induced Vibration (FIV) in highly turbulent cross-flow. The study focuses on wake turbulence and its interaction with the structural response being set in a single degree of Freedom. A novel contribution is presented, where a Reynolds number of 140,000 is numerically studied for FIV-Wake interaction. An unsteady numerical framework is employed for the simulations, incorporating an Arbitrary Lagrangian Eulerian (ALE) method for the associated grid deformation to simulate the coupled motion of the circular cylinder at the starting zone in a typical cylinder-flow response map or what is termed 'initial regime'. Three-dimensional Large Eddy Simulation (LES) and two-dimensional unsteady Reynolds Averaged Navier-Stokes (uRANS) are used to observe the influence of turbulence treatment and domain representation on the simulations carried out. Particular attention is paid towards resolving the large scales of the fluid motion and the inherent coupling of the cylinder's motion towards the associated evolution of the time averaged flow field. Significant changes occur to cylinder hydrodynamics and Reynolds stresses due to flow-induced vibration. Wake mixing is enhanced and kinetic energy production field is qualitatively altered. LES predictions show more accuracy in response and wake dynamics than their uRANS counterpart which -nonetheless- retain a recognisable merit despite the underlying uRANS assumptions. The predictions discussed and analysed in detail in the paper compare reasonably with the chosen benchmark tests of the stationary cylinder. Furthermore, it appears that such use of numerical simulations to tackle high Reynolds number FIV is encouraged and suggests that the conclusions outlined regarding the coupled flow-cylinder system potentially provide a valuable insight.
Original language | English |
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Journal | International Journal of Astronautics and Aeronautical Engineering |
Early online date | 5 Aug 2017 |
DOIs | |
Publication status | Published - 2017 |
Keywords
- Flow-induced vibration
- LES
- uRANS
- turbulence modelling
- cylinder cross-flow
- CFD