Numerical case study of packed sphere wicked heat pipe using Al2O3 and CuO based water nanofluid

In this paper, a two-dimensional numerical model is developed to study the thermal performance of a packed sphere heat pipe utilizing nanofluids due to the recent development of nanofluids and porous media structures. Two of the most common nanoparticles, namely Al2O3 and CuO based water are considered. The substantial change in the heat pipe thermal resistance, liquid pressure, axial and radial velocities profiles in presence of suspended nanoparticles within the base fluid are discussed. The effect of particle size on the thermal performance of the heat pipe is also investigated. Results showed that Al2O3 nanofluid slightly outperformed CuO nanofluid heat pipes especially with decreasing nanofluid particle diameter. It was found that reduction of 68% on thermal resistance can be obtained for 9% CuO nanofluid concentration level which trend to reach 20% without significant shear stress effect. Nanofluid based heat pipe is able to dissipate up to 26% more heat without experiencing an increase in the wall temperature and an optimal nanofluid concentration level and diameter are found to better heat pipe performance.