Engineering and Technology Journal (Mar 2014)
Experimental Investigation of Heat Transfer Enhancement and Flow with Ag, Tio2ethylene Glycol distilled Waternanofluid in Horizontal Tube
Abstract
The present investigates experimentally the pressure drop and convective heat transfer coefficient of ethylene glycol(EG) and distilled water (DW) based Titanium oxide (TiO2 (30nm)) and silver (Ag (50nm)) nanofluidsin horizontal tube (4mm inner diameter ,6mm outer diameter, and length=2.5m) in the fully developed laminar flow. The concentrations of nanofluid mixture used are ranging from (0.5 –5% vol ). The properties of nanofluids (density, viscosity, thermal conductivity and specific heat) are practically measured. The obtained results show an increase in heat transfer coefficient of 35.4% for TiO2 + DW, 30.2 % for TiO2 + (EG + DW), 23.5%, for TiO2+ EG and 50.6 % for Ag + DW, 36.2% for Ag + (EG + DW), 25.7 % for Ag + EG. The measured results show that Ag with distilled water nanofluid gives maximum heat transfer enhancement compared with other nanofluid used. As well as the experimental results show that the data for nanofluids friction factor show a good agreement with analytical prediction from the Darcy's equation for single – phase flow. This paper decided that the nanofluid behaviors are close to the typical Newtonian fluids through the relationship between viscosity and shear rate. Moreover to NuR are used to present the corresponding flow and heat transfer inside the tube
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