NUMERICAL MODELING OF LAMINAR FORCED CONVECTIVE ENHANCEMENT OF (AL2O3-WATER) NANOFLUIDS IN A CIRCULAR PIPE

Abstract

A two-dimensional numerical investigation on laminar forced convection is carried out to estimate the thermal and fluid field behavior of Al2O3-water nanofluid in a circular pipe with constant heat flux. In this study, the finite element method (FEM) is employed to analyze the continuity, momentum, and energy governing equations by using COMSOL Multiphysics 3.5a. Computations of heat transfer rates were performed for a range of Reynolds numbers (Re ≤ 2000), and (Pr= 5.42). The effects of Reynolds number and fraction volume of nanoparticle (ɸ≤ 5%) on the mean coefficient of convection (havg), pressure drop (∆P), and thermal-hydraulic performance are investigated. The computations indicate that Al2O3 nanoparticle usage augments the average coefficient of heat convection significantly, and which is increased by (10%) with maximum pressure loss (15%) for (ɸ=5%) and high Reynolds number when compared to the base fluid. The present model is validated with empirical Shah Equation and the results showed a good agreement.