Two degrees of freedom flow-induced vibration and heat transfer of an isothermal cylinder

•Displacement and surface-averaged Nu change periodically for cylinder in 2DOF FIV.•Cylinder reaches max-amplitude as vortex streets transit from one row to two rows.•Position of maximum local Nu moves periodically along the surface of FIV cylinder.•The averaged Nu of 2DOF FIV cylinder increases by 5.73% than stationary cylinder at U*=6.