Two-dimensional numerical analysis of electro-thermo-convective turbulence in microgravity conditions

This study presents a numerical investigation of electro-thermo-convection (ETC) turbulence resulting from unipolar charge injection under microgravity conditions. Both strong and moderate unipolar injection ETC in a cavity are considered. In the turbulent state, convection driven by electric field forces can effectively mix the flow. The mode decomposition reveals that the flow field exhibits several main modes, whereas the temperature and charge fields are only dominated by a specific mode. Moreover, the flow demonstrates self-similarity under a range of parameters. It is shown that both moderate and strong charge injection conditions can realize effective heat transfer enhancement. The Nusselt number increases with the increase of the electric Rayleigh number and the decrease of the dimensionless mobility. This study also demonstrates that the ETC turbulence can enhance heat transfer by two orders of magnitude compared to the pure conduction state. This enhancement is comparable to the intensity of thermal convection achieved at a Rayleigh number of 10⁹. This study extends prior research on electrohydrodynamics by investigating ETC turbulence. The findings provide valuable reference for experiments and thermal management applications under microgravity conditions.