Influence of the thermo-electric coupling on the heat transfer in cylindrical annulus with a dielectric fluid under microgravity

The present note gives the result of direct numerical simulations of the convective flow induced by the dielectric force in a cylindrical annulus under microgravity conditions. A dielectric fluid confined between two coaxial cylinders is subject to a high-frequency tension and a radial temperature gradient. The resulting buoyancy force creates a supercritical convective flow when the critical value of the electric Rayleigh number is exceeded. This flow is made of stationary helicoidal vortices. The effect of the thermo-electric coupling is sensitive for large values of the radius ratio: it stabilizes the conductive state and reduces the slope of the increase of the heat transfer and of the kinetic energy.