Abstract

The present study explores the effect of damping ratio and Reynolds number on the flowinduced vibration and heat transfer behavior of a heated squaresection cylinder. To this end, fluidstructure interaction simulations based on the finitevolume method are conducted for five different damping ratios of ζ = 0, 0.01, 0.05, 0.1, 0.25 and 0.5 at four representative Reynolds numbers of Re = 80, 90, 220 and 250. By considering the squaresection cylinder as a massspringdamper system, one can model its free vibration along transverse and streamwise directions due to lift and drag forces exerted from the fluid, in which the dynamic mesh technique is employed to couple the cylinder motion with the flow field. Owing to its sharp corners, the squaresection cylinder first experiences the lockin condition in which the vortex shedding frequency approaches the oscillator natural frequency. After surpassing the critical flow velocity, the squaresection cylinder undergoes highmagnitude and lowfrequency oscillations known as galloping. For a more comprehensive evaluation, the designated Reynolds numbers encompass all vibration regions of the squaresection cylinder: out of lockin and galloping (Re = 80), middlepoint of lockin region (Re = 90), middlepoint of galloping (Re = 220) and the peak of galloping zone (Re = 250). The results show that at Re = 90, as the damping ratio increases from ζ = 0.01 to ζ = 0.05, the amplitude of cylinder oscillations significantly drops due to the desynchronization type action. A notable reduction in the oscillation amplitude at Re = 220 and 250 occurs with increasing damping ratio from ζ = 0.1 to ζ = 0.25, attributed to the hidden frequency emersion phenomenon in which the fundamental frequency of cylinder transverse oscillations shifts to a secondary value. It is also shown that the heat transfer rate of the square cylinder with free vibration is more than that of a stationary cylinder. With increasing damping ratio, the heat transfer
