Onset of Natural Convection Under Electric Field.

Abstract

The convective instability problem in ac and dc electric field is studied theoretically. Linearized perturbation equations are solved by the Galerkin method where the critical ac or dc electric Rayleigh number, the critical Rayleigh number and the critical Marangoni number are expressed as eigen values. It is found that the critical ac electric Rayleigh number, the critical Rayleigh number and the critical Marangoni number become smaller as electric field increases in the case of ac electric field. However, in the case of dc electric field, the critical dc electric Rayleigh number, the critical Rayleigh number and the critical Marangoni number increase with increasing electric field when nondimensional parameters S and K are small while the critical dc electric Rayleigh number, the critical Rayleigh number and the critical Marangoni number decrease with increasing electric field when S and K are large.