Numerical Investigations of Forced Oscillating Circular Cylinder in Uniform Flow

A two-dimensional forced vibration numerical simulation is carried out for a transversely and streamwise oscillating circular cylinder in uniform flow separately. The governing equations for an incompressible flow in a non-inertial frame of reference is solved by the Finite Volume Method (FVM). A Ghost cell immersed boundary method (GCIBM) is applied to the non-body conformal Cartesian grid. The Reynolds number and normalized amplitude of oscillation were kept at constant at 150 and 0.3, respectively. The frequency ratio fr for transversely and the streamwise oscillating circular cylinder is varied as 0.7 ≤ fr ≤ 1.2 and 0.5 ≤ fr ≤ 2.7, respectively. The lock-in zone for transversely and the longitudinally oscillating circular cylinder were found to be in the frequency ratio of 0.75 ≤ fr ≤ 1.05 and 1.15 ≤ fr ≤ 1.9, respectively. The wake patterns closely match the reported results. The average force coefficients are plotted against fr and showed the same trend as that of the reported results. In streamwise there are two types of lock-in zone found, harmonic and sub-harmonic region are being observed. Coefficient of energy is increased from 0 to 0.6 in transverse and in streamwise. The value of coefficient of energy is decreased from 0 to −3.