An overset mesh approach for a vibrating cylinder in uniform flow

Abstract

This paper has numerically investigated twodimensional laminar flow over a vibrating circular cylinder. Numerical simulation is performed using the dynamic overset mesh method available in commercial software ANSYS FLUENT 19.0. A simple harmonic motion is applied to simulate the cylinder vibration using the user-defined function (UDF) tool in FLUENT. To examine the accuracy and the capability of the present overset mesh approach, two test types of cylinder vibration are simulated: crossflow and inline vibrations. All simulations are performed at a constant Reynolds number (Re = 100) to predict the occurrence of synchronization or lock-in phenomenon. For the case of crossflow vibration, it is observed that lock-in occurs with cylinder oscillation frequency near the Strouhal frequency of the fixed cylinder. However, for the inline vibration, lockin occurs near twice the Strouhal frequency of the fixed cylinder. Furthermore, in the case of crossflow oscillation, the frequency content in the lift coefficients’ time history is successfully linked to the phase portraits’ shape and the vorticity field. The simulation results are consistent with the available published data in the literature. This indicates that the present numerical technique is valid and capable of modeling flows with moving structural systems.

Keywords

• cylinder vibration
• laminar flow
• overset mesh
• fast fourier transform
• crossflow
• inline vibration