PENETRATIVE THERMO-GRAVITATIONAL AND SURFACE- TENSION DRIVEN CONVECTION IN A FERROFLUID LAYER THROUGH VOLUMETRIC INTERNAL HEATING WITH VARIABLE VISCOSITY

This work pertaining to analytical and numerical studies on FTC in a FF layer with impact of coupled buoyancy-gravitational and surface-tension forces through the strength of internal heat source on the system subjected to the magnetic field dependent (MFD) viscosity effect. The lower boundary is considered to be rigid at either conducting or insulating to temperature perturbations, while upper boundary free open to the atmosphere is flat and subject to a Robin-type of thermal boundary condition. The Rayleigh-Ritz method with Chebyshev polynomials of the second kind as trial functions is employed to extract the critical stability parameters numerically. The onset of FTC is delayed with an increase in MFD (δ ) parameter and Biot number (Bi) but opposite is the case with an increase in Rayleigh number (M1), non-linearity of fluid magnetization (M3) and strength of internal heat source (Ns). Their effects are complementary in the sense that the critical Mac and Rmc decrease with an increase in Rt.