Since in most industrial rotating equipment, increasing thermal efficiency and reduction of drag has always been subject of interest, in this paper, a 2-D numerical investigation on mixed convection heat transfer and drag coefficient in a lid-driven square cavity filled with Al2O3 Nanofluid is done under the effect of an inner rotating cylinder. To analyze effective parameters on heat transfer and drag coefficient on movable wall, a sensitivity analysis is carried out utilizing the Response Surface Methodology. Simulations are performed for effective parameters of the Richardson number (0.1 ≤ Ri ≤ 10), dimensionless rotational speed (0 ≤ Ω ≤ 5), a/b ratios (0.5 ≤S ≤ 1), and the Nanoparticle volume fraction (0.00 ≤ Ф ≤ 0.03) with a constant Grashof number of 104. It is found that the mean Nusselt number enhances with Ri number and Ф and decreases with increasing of Ω and S. Additionally, increasing the Ri number and Ω increases the drag coefficient but it reduces as Ф and S increase. The sensitivity analysis results showed that to maximize the mean Nu number and minimize the drag coefficient simultaneously, the effective parameters must be Ω = 0, Ri= 0.13636, Ф = 0.03 and S = 0.5.

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