We consider the response of a flexibly mounted square prism placed in inertial-viscoelastic fluid flow with one degree-of-freedom in the cross-flow direction. Under these flow conditions, both inertia and elastic effects are significant. We model the system numerically using a two-way coupling scheme to simulate the interaction between the fluid and the spring–mass system at a Reynolds number of Re=200 for two mass ratios of m^* = 2 and 20, and a Weissenberg number of Wi=2, across a range of reduced velocities. We demonstrate that introducing fluid elasticity suppresses vortex-induced vibrations of square prisms, consistent with prior findings for circular bluff bodies. However, we find that fluid elasticity amplifies the galloping response in comparison with the response in a Newtonian fluid, leading to larger oscillation amplitudes and the onset of galloping at lower reduced velocities. The predicted enhancement in galloping is significant, particularly at low mass ratios, where no galloping is observed over the wide reduced velocity range tested for Newtonian fluids. We show that this enhancement of galloping is likely the result of the observation that the addition of viscoelasticity increases the magnitude of the rate of change of the transverse flow-induced force on the prism with increasing angle of attack of the incoming flow.
Gong et al. (Thu,) studied this question.