RANS Simulation vs. Experiments of Flow Induced Motion of Circular Cylinder With Passive Turbulence Control at 35,000<Re<130,000

Abstract

Two-dimensional RANS equations with the Spalart-Allmaras turbulence model are used to simulate the flow and body kinematics of a rigid circular cylinder mounted on springs, transversely to a steady uniform flow in the high-lift, TrSL3 regime with 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 by using a solver based on the open source CFD tool OpenFOAM, which solves continuum mechanics problems with a finite volume discretization method. Roughness parameters of PTC are simulated modeling tests conducted in the Marine Renewable Energy Lab (MRELab) of the University of Michigan. The numerical tool is first tested on smooth cylinder in VIV and results are compared with available experimental measurements and RANS simulations. For the cylinder with PTC cases, the sandpaper grit (k) on the cylinder wall is modeled as a rough-wall boundary condition. Two sets of cases with different system parameters (spring constant, 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, 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.