الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 211 |  |  |
| | | from | 211 | | |
Abstract
Laminar forced convective heat transfer and friction factor for nanofluid flow inside a circular horizontal tube numerically investigated and validated by the experimental results under uniform heat flux. Two different numerical models are used to study heat transfer enhancement due to the use of nanofluids. Single phase model is used and compared with two phase model to predict the heat transfer enhancement techniques due to using nanofluids. Different high loading nanoparticle concentrations are used in CFD model. Both Al2O3 and CuO nanoparticles of size 60 nm with different concentrations of (0.2%, 1%, 2%, 3% and 4% by volume) are used in the present study. Experiments were conducted using (Al2O3) nano-particles added to water at a concentration of 0.2% by volume to validate each of the two CFD models. Results have shown that the two phase model is the most appropriate to predict heat transfer in nanofluids with high particle loading. Heat transfer enhancement is about 46% at the mean velocity of (0.02 m/s) for 4% CuO. This enhancement of heat transfer coefficient is due to the increase in fluid thermal conductivity and Brownian motion of solid particles which decreases the thermal boundary layer thickness.