Simulation of free convection heat transfer of non-Newtonian nanofluids in a cylindrical

One way to increase the heat transfer rate adding nanoparticles to the fluid and is making Nano fluids. Free convection heat transfer in cylindrical geometry, due to their widespread use in the chemical engineering industry and is of utmost importance. In this study free convection heat transfer by Non-Newtonian Nano fluids in a cylindrical chamber, using computational fluid dynamics were studied. For prepare the Nano fluids two types of nanoparticles Al2O3 and TiO2 was used. Effect of type and concentration of nanoparticles and also the aspect ratio cylindrical heat transfer rate were investigated. Independency of mesh operation was carried out by testing three different mesh and finally was selected the best mesh in terms of accuracy and computational time. The results of the simulations were compared with the results of empirical correlations valid. The results were in good agreement with experimental results. The results showed that low concentrations of nanoparticles significantly increase the heat transfer rate. But further increase the concentration of nanoparticles has a negative effect and decrease the transmission rate. In fact, in optimum concentrations of nanoparticles, the maximum heat transfers. The results show that the distribution of TiO2 nanoparticles is greater than the effect of Al2O3 distribution.