The heat transfer enhancement by utilizing hybrid nanofluid is a new class of heat transfer enhancement. In this paper, CFD model with commercial software adopting the finite volume method and SIMPLE algorithm has been conducted. Mixture of Aluminum Nitride (AlN) and alumina (Al₂O₃) nanoparticles into water as a base fluid is considered as a new concept of hybrid nanofluid for enhancing heat transfer. It was performed the simulation procedures with the volume fraction (1, 2, 3 and 4%) and Reynolds number are changing from 5000 to 17000. The heat flux applied along the elliptical tube is 7000 w/m² and the nanoparticles size diameter is fixed at 35 nm. The validation of computational results has been performed with experimental data available in the literature. The results indicated that the hybrid nanoparticles of AlN - Al₂O₃ suspended in water as a base fluid tends to enhance heat transfer significantly.