| Influence of yield stress on free convective boundary-layer flow of a non-Newtonian nanofluid past a vertical plate in a porous medium
F. M. Hady, F. S. Ibrahim, S. M. Abdel-Gaied and M. R. Eid*
The Journal of Mechanical Science and Technology, vol. 25, no. 8, pp.2043-2050, 2011
Abstract : The effect of yield stress on the free convective heat transfer of dilute liquid suspensions of nanofluids flowing on a vertical plate saturated
in porous medium under laminar conditions is investigated considering the nanofluid obeys the mathematical model of power-law.
The model used for non-Newtonian nanofluid incorporates the effects of Brownian motion and thermophoresis. The governing boundary-
layer equations are cast into dimensionless system which is solved numerically using a deferred correction technique and Newton
iteration. This solution depends on yield stress parameter Ω, a power-law index n, Lewis number Le, a buoyancy-ratio number Nr, a
Brownian motion number Nb, and a thermophoresis number Nt. Analyses of the results found that the reduced Nusselt and Sherwood
numbers are decreasing functions of the higher yield stress parameter for each dimensionless numbers, n and Le, except the reduced
Sherwood number is an increasing function of higher Nb for different values of yield stress parameter.
Keyword : Non-Newtonian; Free convection; Nanofluid; Porous media; Yield stress |
