Abstract
The objective of this study is to numerically investigate the mixed convection in a lid-driven cavity filled by a nanofluid with an inside circular cylinder. The inner circular cylinder inside cavity is maintained at two different cases as isothermal and adiabatic boundary conditions, respectively. The upper wall of the cavity is moving with constant temperature. The vertical walls of the cavity were taken as adiabatic and the bottom wall has constant temperature. The nanofluids on the cavity walls and inner cylinder is passively controlled. We studied the effects of Reynolds, Grashof, buoyancy ratio, Brownian motion, thermophoresis parameters and the radius with positions of circular cylinder on the heat transfer, nanoparticle concentrations and fluid flows inside cavity. The current results show that the position and radius of inner circular cylinders have clear effects on the fluid flow heat transfer characteristics and nanoparticle concentrations. The obtained results have been compared with previous numerical results from previous published studies with a well agreement.