Pressure field analysis on oscillating circular cylinder

The flow–structure interaction of an oscillating circular cylinder in the synchronization field at sub-critical Reynolds number is still an open research point, both in terms of experimental description and in terms of available numerical simulation models. The complexity of the problem is mainly due to the relevant nonlinear effects induced by the oscillating cylinder on the flow field. Evidence of this is given by the possible co-existence of different solutions to the nonstationary fluid-dynamic problem, switching from one to the other depending on minor changes in the key nondimensional parameters governing the phenomenon (nondimensional oscillation amplitude and critical velocity ratio). The tests described have been realized in air using a rigid model elastically suspended and instrumented by an on-board high frequency response pressure scanner. The instantaneous pressure distribution on a cylinder section has been measured allowing identification of different vortex shedding states and calculation of aerodynamic integral forces on the cylinder and their correlation with the motion time histories.