The effect of wall speed ratios on magnetohydrodynamic (MHD) mixed convective flow in a square cavity filled with CuO-water nanofluid, incorporating a diagonally moving heated/cooled wall, is examined. The governing equations, which account for magnetic field effects, buoyancy forces, and nanoparticle concentration, are solved numerically using the finite volume method with the SIMPLE algorithm. The study investigates the effects of wall speed ratios ($\gamma$ = 0, 1, 2), Richardson numbers (Ri = 0.1, 1, 10), Hartmann numbers (Ha = 0, 10, 25, 50), and nanoparticle volume fractions ($\phi$ = 0.0, 0.05) on flow behavior and convective heat transfer within the cavity. The results demonstrate th... More >