Numerical analysis of the forced convective heat transfer on Al2O3-Cu/water hybrid nanofluid

A numerical investigation to elucidate thermal behavior of hybrid nanofluids consisting of Al2O3 and Cu nanoparticles at ratio of 90:10 was conducted. Numerical domain of a two-dimensional axisymmetric copper tube with a length of 1000 and 10 mm in diameter is used. A uniform axial velocity is assigned at the velocity inlet based on the Reynolds number. The outer wall of the tube consists of non-slip wall condition with a constant heat flux. The assumptions of this numerical analysis are; (1) there is a steady state analysis, (2) effective thermo-physical properties of the nanofluid are depend on the volume concentration, and (3) fluid is continuum. It is found that the dominant nanoparticle in the hybrid nanofluids strongly influences the thermal behavior of the hybrid nanofluids. It was also found that the heat transfer coefficient increases as the volume concentration of the hybrid nanoparticle increases in base fluids and the Reynolds number.