Computational Heat Transfer Analysis of Oxide Nanofluids Around a Fixed Heated Cylinder

Nanofluids are helpful to improve the effectiveness of thermal systems for different industries, which helps in producing energy in an environmentally sustainable manner, downsizing the systems and enhancing profitability. In this study, the heat transfer characteristics of a nanofluid flowing over a circular cylinder with an axisymmetric heated surface were investigated. Three nanofluids based on the above materials suspended in the water with the volume fractions of the particles equal to 0% to 0.05% respectively, have been used in order to do comparison. The time dependent equations here targeted for simulation are the Navier-Stokes equations of motion in three dimensions. The numerical simulations were performed for a Reynolds number Re=200,0^∘≤θ⌣≤180^∘ and Pr = 6.2. The two-dimensional momentum and energy conservation equations were solved (numerical analysis), while varying the order of compact HOC on non-uniform polar grids. Different types of the nanoparticles were used to disperse in the heat conducting fluid in order to understand how the thermal fields in the cylinder would be developed. The results reveal that the application of nanoparticles improves heat transfer by a greater measure because it increases the Nusselt number which reflects greater convection and conduction. The highest Nusselt numbers are recorded at the stagnation point, where convective heat transfer reaches its maximum in accordance with the level of shear. The thermal conductivity of Al₂O₃ and SiO₂ nanoparticles raise the heat transfer rate, and so does the proper selection of concentration of applied nanoparticles, which is required to enhance the thermal efficiency of the cooling system.