DOUBLE-DIFFUSIVE CONVECTION IN A DIELECTRIC VISCOELASTIC NAVIER-STOKES-VOIGT FLUID: EFFECT OF AN AC ELECTRIC FIELD AND BOUNDARY CONDITIONS
H. Singh1, A. Sharma1,2, D. Prakash1,2
1Kanwar Durga Chand Government College, Jaisinghpur, India
2Himachal Pradesh University, Shimla, India
Keywords: concentration Rayleigh number, electroconvection, Navier-Stokes-Voigt model, oscillatory convection, Prandtl number, stationary convection
Abstract
The effect of a vertical AC electric field on a layer of a dielectric viscoelastic Navier-Stokes-Voigt fluid, salted from below and heated either from below or from above, is investigated using linear stability theory. The eigenvalue problem is solved exactly for stress-free boundary conditions, while the Galerkin method is employed for rigid boundaries. A numerical analysis of the influence of the electric field on the system is performed for both stationary and oscillatory convection modes. It is found that stationary convection occurs at low values of the concentration Rayleigh number, while a transition to oscillatory convection takes place at higher values. The Navier-Stokes-Voigt parameter plays a significant role in stabilizing the onset of oscillatory convection. The system is shown to be more stable when heated from above than when heated from below. The results obtained are in good agreement with available data in the literature.
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