Complex flow patterns at the onset of annular electroconvection in a dielectric liquid subjected to an arbitrary unipolar injection

Jian Wu (1) , Alberto Perez (1) , Philippe Traore (2) , Pedro Vazquez (3)

1 Departamento de Electrónica y Electromagnetismo [Universidad de Sevilla]
2 PPrime [Poitiers] - Institut Pprime [UPR 3346]
3 Faculty of Physics [Sevilla University] | Facultad de Física [Universidad de Sevilla]

We numerically investigated the annular electroconvection that takes place in a dielectric liquid lying between two concentric cylinder electrodes. A uniform injection of arbitrary strengths either from the inner or outer cylinder introduces free charge carriers into the system, and the resulting Coulomb force induces electroconvection. The problem is characterized by a linear instability that corresponds to the onset of flow motion. The linear stability criteria were determined from direct numerical results and by linear stability analysis, and the results obtained with the two approaches show an excellent agreement. We focused on the fully developed flow pattern in the finite amplitude regime. We observed very different flow motions that were highly dependent on the injection strength.

Mots clés: Electrohydrodynamics; dielectric liquid; charge injection; numericalanalysis; annular geometry

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]

Jian Wu, Alberto Perez, Philippe Traore, Pedro Vazquez. Complex flow patterns at the onset of annular electroconvection in a dielectric liquid subjected to an arbitrary unipolar injection. IEEE Transactions on Dielectrics and Electrical Insulation, 2015, 22 (5), pp.2637-2645. ⟨10.1109/TDEI.2015.005157⟩. ⟨hal-03671769⟩