Couette-Taylor flow under a thermoelectric body force in microgravity

International audienceThe Couette-Taylor flow of dielectric fluids is investigated under a radial temperature gradient and a radial high-frequency electric field, where a thermoelectric coupling gives rise to the dielectrophoretic body force on the fluids. The latter force acting in the radial direction can be deemed as thermal buoyancy due to an effective gravity ge. This gravity can provoke a thermal convection even in microgravity, when the Rayleigh number based on ge is larger than a critical value [Yoshikawa et al., Phys. Fluids, 2013, 25:024106]. In the absence of cylinders rotation, the critical mode is stationary and is made of helices [Malik et al., Acta Astronaut. 2012, 81:563–569]. Considering a rotating inner cylinder, we will discuss the competition between this thermoelectric instability and the centrifugal instability. A stability theory accompanied by an energetic analysis will be presented to this aim