Numerical Investigation of Ag-H2O Nanofluid in a Lid Driven Square Cavity with Different Shaped Conducting and Insulating Cylinders Placed at Centre

A numerical analysis is carried out in a lid-driven cavity using silver (Ag)-water nano-fluid by keeping different shape of conducting as well as insulating cylinders at the centre. The cavity is heated isothermally by a heater placed at the bottom. The right and the left walls are in insulated condition and the upper cold wall is moving with some constant speed. The thermal performance of the nanofluid with the cylinder is being analyzed at two Richardson number (Ri=0.01, 10), four percentage volume of Ag nanoparticles (0 %, 2 %, 5 %, 8 %), and a constant value of Grashof and Prandtl number as 10(4) and 6.2 respectively. The two-dimensional, incompressible and steady Navier-Stokes equations are solved using the commercially available Finite-volume based software Fluent. It is analysed that the thermal mixing inside the enclosure is highly dependent on the shape of a solid cylinder. Moreover, the insignificant variation in flow and thermal field is observed with change in the thermal boundary conditions (insulation and conduction) of centrally placed solid cylinder for all the range of Richardson number (Ri). With increase in percentage volume of nanoparticle Nusselt number (Nu) increases whereas Ri has reverse effect on Nu.