Heat Transfer Performance of Nanofluid in a Complicated Cavity Due to Prandtl Number Variation

A numerical investigation is presented for the natural convective flow and thermal behaviors of nanofluid inside a complicated enclosure due to Prandtl number variation. The cavity consists of a centered heated diamond shaped hollow obstacle. The vertical walls are constantly and uniformly less heated than the obstacle. The bottom surface of the cavity is adiabatic. The upper horizontal part of the enclosure is surrounded by solid material with constant thermal conductivity. The upper boundary of this solid region is considered as adiabatic. The working fluid is water based nanofluid having copper nanoparticles. The governing equations are solved numerically using Galerkin's Weighted Residual Finite Element method. Results are presented in the form of average Nusselt number, average temperature, mean velocity of the nanofluid, mid height horizontal and vertical velocities for a selected range of viscosity parameter Pr (4.2 – 8.8). Streamlines and isothermal lines are also displayed for the above mentioned parameters. The results show that the increment in Pr enhanced the rate of heat transfer.