Numerical Investigation on Lock-In Condition and Convective Heat Transfer From an Elastically Supported Cylinder in a Cross Flow

In this numerical study, flow-induced vibrations of a heated elastically supported cylinder in a laminar flow with Re = 200 and Pr = 0.7 are simulated using the moving overset grids method. This work is carried out for a wide range of natural frequencies of the cylinder, while for all cases mass ratio and reduced damping coefficient, respectively, are set to 1 and 0.01. Here we study lock-in condition and its effects on force coefficients, the amplitude of oscillations, vortex shedding pattern, and Nusselt number and simultaneously investigate the effect of in-line oscillations of the cylinder on these parameters. Results show that for this cylinder, soft lock-in occurs for a range of natural frequencies and parameters like Nusselt number, and the amplitude of oscillation reach their maximum values in this range. In addition, this study shows that in-line oscillations of the cylinder have an important effect on its dynamic and thermal behavior, and one-degree-of-freedom simulation, for an elastic cylinder, which can vibrate freely in a flow field, is only valid for cases far from soft lock-in range.