RANS Simulation Versus Experiments of Flow Induced Motion of Circular Cylinder With Passive Turbulence Control at 35,000 < RE < 130,000

Abstract

Twodimensional (2D) Unsteady ReynoldsAveraged Navier–Stokes equations (URANS) equations with the Spalart–Allmaras turbulence model are used to simulate the flow and body kinematics of the transverse motion of springmounted circular cylinder. The flow is in the highlift TrSL3 regime of a Reynolds number in the range 35,000 < Re < 130,000. Passive turbulence control (PTC) in the form of selectively distributed surface roughness is used to alter the cylinder flow induced motion (FIM). Simulation is performed using a solver based on the open source Computational Fluid Dynamics (CFD) tool OpenFOAM, which solves continuum mechanics problems with a finitevolume discretization method. Roughness parameters of PTC are chosen based on tests conducted in the Marine Renewable Energy Lab (MRELab) of the University of Michigan. The numerical tool is first tested on smooth cylinder in vortexinduced vibration (VIV) and results are compared with available experimental measurements and URANS simulations. For the cylinder with PTC cases, the sandpaper grit on the cylinder wall is modeled as a roughwall boundary condition. Two sets of cases with different system parameters (spring, damping) are simulated and the results are compared with experimental data measured in the MRELab. The amplitude ratio curve shows clearly three different branches, including the VIV initial and upper branches, and a galloping branch. The numerical branches are similar to those observed experimentally. Frequency ratio, vortex patterns, transitional behavior, and lift are also predicted well for PTC cylinders at such high Reynolds numbers.