Numerical study of heat transfer enhancement with the use of nanofluids in radial flow cooling system

In the present study, mathematical modeling is performed to simulate the forced convection flow of Al2O3-water nanofluid in the radial flow cooling system using a single-phase approach. Computations are validated with experimental data available in the literature. Results show the same trend as revealed in most of the published works that the heat transfer coefficient increases with the increase of the Reynolds number and the nanoparticle volume fraction, though the increase in pressure drop is more significantly associated with the increase of particle concentration. When taking both the cooling performance and the adverse effect of pressure drop into consideration, no better heat transfer enhancement is found with the use of nanofluid compared to that of pure water under the laminar, medium-heat flux conditions in the radial flow system. Furthermore, the model considering Hamilton-Crosser formula for effective conductivity along with the equation developed by Brinkman for effective viscosity of nanofluid might result in the overprediction of the capability of applying nanofluids to remove heat.