Vol.22, No.1, 2022, pp. 85–93
UDC:

Linear stability convection in a nanofluid layer of pulsating throughflow and rotating about the vertical saturating a porous layer heated at the lower surface with the inclusion of an external vertical AC electric field is developed for realistic boundary conditions, in which volume fraction flux of nanoparticles is taken to be zero on the isothermal boundaries. The basic profile for temperature gets altered for this flow and the volumetric fraction of nanoparticle vary from linear to nonlinear with layer height, which marks the stability expressively. The exact solutions of the characteristic equation for both stress-free bounding surfaces are obtained analytically and the expressions of the thermal Rayleigh number for onset of both oscillatory and stationary modes are derived in terms of a variety of non-dimensional involved parameters. The pulsating throughflow, rotation and Lewis number are found to decrease size of the cellular stationary modes, whereas these are increased with rise in modified diffusivity ratio, the electric Rayleigh number, the medium porosity and Rayleigh number of nanoparticle concentration. The occurrence of oscillatory mode is ruled out for the realistic boundary conditions. The numerically computed values of the thermal Rayleigh number for stationary modes are plotted.

Keywords: nanofluid, pulsating throughflow, electric field, rotation, porous medium