Thermal convection of viscoelastic fluids in concentric rotating cylinders: Elastic turbulence and kinetic energy budget analysis

We perform a comprehensive numerical study on all three modes of thermal convection (forced, free, and mixed) within a system comprising two concentric horizontal cylinders filled with viscoelastic fluids, with the inner cylinder rotating. In forced convection, the flow field remains stable, while in free and mixed convection, an increase in the Weissenberg number leads to a transition from steady to unsteady periodic, quasiperiodic, and finally, an aperiodic and chaotic behavior. This transition arises due to the presence of elastic instability and the subsequent appearance of elastic turbulence in viscoelastic fluids with the increasing Weissenberg number.