Numerical Simulation into the Convective Heat Transfer of Al₂O₃ and Cuo Nanofluids Flowing through a Straight Tube Using the Two Phase Modeling

摘要

The main purpose of this study is focused on numerical investigation of thermal behavior of Copper oxide-water nanofluids and Aluminum oxide-water nanofluids inside a horizontal heated tube. The model has been solved by using the two-phase models with four correlations of thermal conductivity. The discretization of equations of continuity, momentum, and energy has been done using the Finite Volume Method. A uniform and constant heat flux has been applied at the wall boundary conditions. The results show that the heat transfer coefficient predicted by the two phase model is enhanced by increasing the volume fraction of nanoparticles for all Peclet numbers; when the Peclet number is low, increasing the volume fraction of nanoparticles will enhance the convective heat transfer in the entrances region of the pipe and gradually decrease along the axial distance of the channel. Also, it is found that the enhanced heat transfer is greater for use the models of thermal conductivity which depend on the temperature than in the constant models. Comparison between predicted results and experimental data from literature is carried out which indicates the two phase is more precise.