Paper Title
Effect of using Nanofluids on Hydrauthermal Characteristics of Straight Tube

Abstract
The present work investigated the effect of using TiO2-pure water and CuO-water nanofluids on heat transfer and pressure drop in a straight tube with circular cross section with 20 nm average diameter of nano particles and 0.5%, 0.75, and 1% volume fraction numerically.The numerical analysis includes the numerical simulation of straight tube model by a package ANSYS FLUENT 18 for constant heat flux of 3000 W/m2, the Reynolds number range of 104 to 105. The results showed that using of nanofluid increased heat transfer coefficient and friction factor by 42% and 41%, respectively for the nanofluids at all Reynolds numbers.It found improvement in thermal performance of nanofluids compared with that of the pure water. The numerical consequences Nusselt number and friction factor are validated with the literature results obtainable and display good agreement, with a deviation of 16.38% and 13.21% respectively. Keywords - Nanofluids, concentration fraction, pure water, numerical, straight tube.