الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The experimental study were performed to investigate the heat transfer
and frication factor characteristics of a AL2O3/Water Nano-fluid mixture
containing alumina nanoparticles flowing in a circular pipes with differences
inner diameter (2 mm, 4 mm, 6 mm, and 8 mm) under constant heat flux. The
Reynolds number are varied from 2500 to 12500, also the Nano-fluid
concentration are changed 0.1 %, 0.2 %, 0.3 %. The effect of inner diameter,
Nano-fluid concentration is presented on heat transfer rate, Nusselt number, and
fraction factor. The experimental results showed that the heat transfer as well as
Nusselt number influence by Nano-fluid concentration. where the Nusselt
number for Nano-fluid of 0. 3% is improving by 15.67 % compared with based
water for high Reynolds number for all value of inner diameter. At high Nanofluid
concentration (0.3 %) the improvement of heat transfer is found to 77.1 %
and 75.98 % for inner diameter of 2 mm and 4 mm respectively.
On the other hand the frication factor is increase with increase of Nanofluid
concentration through the pipe for all inner diameters. where the frication
factor of 0.3 % Nano-fluid is increases by 24.2 % compared with based water at
low Reynolds number (R = 2500). For high Reynolds number (Re 12500), the
increases of frication factor reduce to 21. 3 % compared with based water for
inner diameter of 6 mm.
The enhancement factor is calculated through this study. where the value
of enhancement factor of 0.3 % Nano-fluid is improved by 30 % compared with
based water at Low Reynolds number (Re = 2500). For high Reynolds number
(Re =12500) the improvement of enhancement factor reduce to 17.4 % for inner
diameter of 4 mm. Finally enhancement factor is maximum value at inner
diameter of 4 mm for all value Nano-fluid concentration. where this value is
II
1.28 for inner diameter of 4 mm. While this value is reduce to 1.21 and 1.2 for
inner diameter of 2 mm, and 8 mm respectively for Nano-fluid of 0.3%.