## THERMAL SCIENCE

International Scientific Journal

### MAGNETOHYDRODYNAMIC FREE CONVECTION OF NON-NEWTONIAN POWER-LAW FLUIDS OVER A UNIFORMLY HEATED HORIZONTAL PLATE

**ABSTRACT**

The MHD free convection flow of non-Newtonian power-law fluids over a horizontal plate subjected to a constant heat flux is studied. The results are presented for various values of the three influential parameters, i. e. the generalized Hart¬mann number, the generalized Prandtl number, and the non-Newtonian power-law viscosity index. Increasing the Hartmann number increases the thermal boundary-layer thickness and the surface temperature and consequently decreases the wall skin friction and Nusselt number. A lower generalized Prandtl number results in a larger skin friction coefficient and higher wall temperature as well as thicker thermal boundary-layer. The viscosity index is predicted to influence the flow conditions depending on the value of generalized Hartmann number. At high generalized Prandtl number numbers, by decreasing non-Newtonian power-law index, the wall skin friction, temperature scale, and thermal boundary-layer thickness are increased and the Nusselt number is decreased, while the opposite trend is observed for low generalized Prandtl number. A general correlation for the Nusselt number is derived using the numerical results

**KEYWORDS**

PAPER SUBMITTED: 2019-01-02

PAPER REVISED: 2019-03-13

PAPER ACCEPTED: 2019-03-15

PUBLISHED ONLINE: 2019-04-07

**THERMAL SCIENCE** YEAR

**2020**, VOLUME

**24**, ISSUE

**Issue 2**, PAGES [1323 - 1334]

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