An Experimental Study on Heat Transfer and Pressure Drop of CuO-Water Nanofluid

Table 1

Experimental studies of water based CuO nanofluids.

Author	Base fluid	Particle material	Volume fraction (vol.%)	Channel geometry and dimension	Flow regime	Results and remarks
Asirvatham et al. [18]	Water	CuO	0.003	Copper tube; : 1.5 m; ID: 8 mm	Laminar	(i) The nanoparticles increased the heat transfer up to 8%; (ii) At the entrance region, the heat transfer enhancement increased and decreased with the increasing axial distance; (iii) As the temperature increased, the energy exchange of the nanoparticle-base fluid contact increased
Selvakumar and Suresh [19]	Water	CuO	0.1, 0.2	Heat sink; 55 × 55 × 75 mm	Turbulent	(i) The interface temperature was reduced between the heater and water block; (ii) The heat transfer enhanced by the use of the nanoparticles in the base fluid; the maximum heat transfer enhancement was approximately 29%; (iii) The increase of the pressure drop was less than the increase in the convective heat transfer
Fotukian and Esfahany [8]	Water	CuO	0.039, 0.078, 0.118, 0.157, 0.236	Circular tube; : 1 m; OD: 32 mm; Thick: 5 mm	Turbulent	(i) The nanoparticles concentration did not show much effect on heat transfer enhancement in turbulent regime; (ii) The ratio of convective heat transfer coefficient of nanofluid to that of pure water decreased with the increasing Reynolds number
Saeedinia et al. [20]	Oil	CuO	0.02, 0.5, 1, 2	Circular tube; : 1200 mm; OD: 15.8 mm; ID: 14 mm	Laminar	(i) The suspended CuO nanoparticles increased the heat transfer, even for a low volume fraction; (ii) The maximum heat transfer enhancement of oil based nanofluid was approximately 12.7% at 2.0 vol.%
Pooyan Razi et al. [21]	Oil	CuO	0.2, 0.5, 1, 2	Round copper tubes; : 1200 mm; OD: 12.7 mm; Thick: 0.6 mm	Laminar	(i) Remarkable heat transfer enhancement was observed as well as the pressure drop by the inclusion of the nanoscaled particles into the base fluid; (ii) As the tube profile became more flattened, the heat transfer enhancement increased, and the same behaviour was valid for the pressure drop; (iii) The maximum heat transfer enhancement was 26.4% at 2% vol. for the flattened tube compared to the pure oil.

: length of the test tube, OD: outer diameter, ID: inner diameter, and Thick: thickness.