Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8062394 | Ocean Engineering | 2018 | 12 Pages |
Abstract
This paper deals with the numerical simulation of low-Reynolds-number flow around a freely vibrating circular cylinder in two-degrees-of-freedom. The governing equations are written in a non-inertial system fixed to the moving cylinder and solved using finite difference method. The natural frequency of the cylinder is chosen to be constant, agreeing with the vortex-shedding frequency for a stationary cylinder at Reynolds number Re0. Systematic computations are carried out for Re0â¯=â¯80, 100, 140 and 180 keeping the mass ratio and structural damping coefficient at m*â¯=â¯10 and ζâ¯=â¯0. The effect of Re0 on the root-mean-square (rms) values of cylinder displacements and drag coefficients is analyzed. Plotting the data set belonging to different Re0 values against U*St0 makes comparison easier. Local extreme values are found in the rms of streamwise displacement and drag coefficient in the range U*St0â¯=â¯0.4-0.65. In the vicinity of U*St0â¯=â¯0.5 the rms of drag approaches zero and the phase angle between the x component of the motion and drag changes abruptly from 0° to 180°. The pressure drag coefficient seems to be responsible for the sudden change. The cylinder follows a distorted figure-eight path in most cases investigated and its orientation changes from clockwise to counterclockwise orbit at around U*St0â¯=â¯0.5.
Keywords
Related Topics
Physical Sciences and Engineering
Engineering
Ocean Engineering
Authors
Dániel Dorogi, László Baranyi,