Calculation study on the influence of mass ratio on VIV of a 2-DOF cylinder

Key words:  vortex-induced vibration  solid-fluid interaction  mass ratio  numerical simulation

Abstract:

An iterative solution algorithm was developed to solve the cylindrical motion equation using Fluent UDF codes and dynamic mesh method, through which the numerical simulation of the vortex-induced vibration (VIV) of a two degree of freedoms (2-DOF) elastically mounted cylinder at a certain reduced velocity. And the influence of different mass ratios on the VIV lift was analyzed. It is found that the iterative solution algorithm can reasonably predict the VIV of elastically mounted cylinder. And the influence of the VIV lift is significant. Compared to high mass ratio cylinders, low mass ratio cylinders can excite higher amplitude, larger lift coefficient, and the phase angle reverse corresponds with a larger reduced velocity U*. The trajectory of the cylinder transfers from the initial arc figure to "8" figure, and finally to a water drop figure.