Résumé:
Numerical studies of laminar and turbulent forced convection, permanent and stationary through a cylindrical pipe for the case of a heat exchanger and the case of a flat plat solar collector, the calculations are performed for the case of water and nanofluides of metal oxides (Al2O3, CuO, SiO2, TiO2).The fluids are supposed Newtonian. The heat transfer equations governing have been resolved, by the use of finite volume method to discretize the mathematical model equations (continuity, momentum and energy equations). Dynamic and thermal fields are obtained for different values of the Reynolds number ranging from 25 to 900 and for different nanoparticles concentration of (1%, 2%, 3%, 5% and 10%).Analyses of temperature, pressure drop coefficient and the calculation Nusselt number has been realized. The results obtained show that heat transfer is better if we increased the nanoparticles concentration and the Reynolds number, and found that the best transfer fluid is the nanofluid contains nanoparticles of Al2O3followed by CuO and TiO2, and finally SiO2, and an increase of Al2O3 concentration intensifies the heat transfer coefficient without affecting the pressure drop, and another the power dissipated by the fluid transport.
