Electro-thermo-hydrodynamics of Polymer Viscoelastic Fluids with Heat Transfer and Dynamic Properties

The electro-thermo-hydrodynamics (ETHD) is associated with electronic cooling used in both terrestrial and space environments. Owing to the mathematical complexity and strong nonlinear coupling of multiphysics fields, ETHD is limited by certain mechanisms and confined engineering utilization. In this paper, the ETHD phenomenon is numerically implemented in a cavity with a vertical temperature difference, incorporating polymer rheological and heat transfer aspects. The kinetic energy evolution, net charge density, thermal efficiency, and flow instability are analysed. The results reveal that the ETHD in viscoelastic dielectric fluids exhibits more complex hydrodynamic behaviors than that in Newtonian fluids, with an effective lower threshold of instability. The broadband structure of the power spectral density demonstrates chaotic transitions (steady flow-periodic oscillation-quasiperiodic-chaos), which are modulated by the Weissenberg number Wi, Rayleigh number Ra, and electrical Reynolds number Re_E. The flow pattern maps and heat transfer Nu curves cover wide ranges of parameters, and electrical reinforcement enhances heat transfer up to 40 times more than without an electric field. The stability and heat response of polymer additions are dependent on dual thermal-electrical driving factors. This study provides comprehensive physical insight into electrically enhanced heat transfer devices and energy storage/conversion technologies.