Heat Transfer of TiO2/Water Nanofluid in a Coiled Agitated Vessel with Propeller

Experimental heat transfer behavior of graphite–water microfluid in a coiled agitated vessel

“…The maximum average enhancement of 68.51% and 27.29%, corresponding to volume concentration 0.1%, has been obtained for propeller and turbine agitator, respectively. Perarasu and colleagues showed a convective heat transfer coefficient increase of 17.59% for 0.3% volume TiO 2 nanoparticles, and an increase of 28.9% for 0.30% concentration of Al 2 O 3 nanoparticles. The present study indicates that a graphite–water microfluid provides greater heat transfer enhancement than titanium dioxide and aluminum oxide nanofluids.…”

A comprehensive review on heat transfer characteristics of TiO2 nanofluids

“…They found that in turbulence state, the enhancement of heat transfer coefficient was increased by 26% at 1 vol.% particle loading, but was decreased by 12% at 3 vol.% particle loading. Coincidentally, Pak and cho [21] found that for a given flow rate, the heat transfer coefficient of TiO 2 nanofluid was also 12% lower than that of base water at 3 vol.% particle load- Laminar EG (a) h increased with an increase in particle loading ranged from 0.1 to 0.86 vol.% (b) Overall h of nanofluids was increased by 35% comparing to pure EG (c) Nanofluids could significantly improve the dynamic response of the compact reactor-heat exchanger Yogeswaran et al [66] Experimental Milling cooling Turbulent EG (a) The temperature was reduced by 30 percent when using the nanofluid as coolant (b) The tool wear from milling using the EG-based TiO 2 nano-coolant was much less and the tool life was increased Hejazian et al [67] Numerical Horizontal circular tube Turbulent Water (a) h increased with the particle loading and Re (b) The model based on two-phase mixture exhibited better accuracy than single phase approach when compared with experimental data Abbassi et al [68] Experimental Vertical annulus Laminar to transitional Water (a) h of nanofluids was higher than water and increased with an increase in particle loading (b) Nanofluids has no major impact on h when volume loading below 0.5% (c) Addition of nanoparticles to 1.5% volume fraction doubled heat transfer coefficient Khedkar et al [69] Experimental Tube Turbulent Water (a) Got higher cooling rate than water for the same range of Re (b) h increased with an increase in particle loading and Re Bhanvase et al [70] Experimental Tube Laminar EG/W (4:6) (a) h increased with an increase in particle loading ranged from 0 to 0.5 vol.% (b) The maximum enhancement of h was 105% at 0.5 vol.% particle loading Reddy and Rao [71] Experimental Tube Transitional to turbulent EG/W (4:6) (a) Nu and h increased with an increase in particle loading ranged from 000,004 to 0.02 vol.% and Re ranged from 4000 to 15,000 (b) The maximum enhancements of h and friction factor were increased by 10.73% and 8.73% at 0.02 vol.% loading Perarasu et al [72] Experimental Coiled agitated vessel Turbulent Water (a) h increased with an increase in particle loading ranged from 0.1 to 0.3 vol. % (b) The maximum enhancement of h was 17.59% at 0.3 vol.% particle loading Barzegarian et al [73] Experimental Brazed plate heat exchanger Laminar Water (a) The maximum enhancement of local h at 0.3%, 0.8% and 1.5% particle weight loading were 6.6%, 13.5% and 23.7% respectively (b) The maximum enhancement of overall h at 0.3%, 0.8% and 1.5% particle weight loading were about 2.2%, 4.6% and 8.5 respectively (c) Pressure drop was negligible due to the low particle loading Arulprakasajothi et al [74] Experimental Horizontal tube Laminar Water (a) Nu increased by 10%, 11.2%, 12% and 16.3% at particle volume loading of 0.1%, 0.25%, 0.5% and 0.75% respectively (b) Nu enhancement was higher than that in friction factor Abdolbaq et al [75] Numerical Straight channel Turbulent Water (a) Nu and friction factor increased with particle loading (b) The friction factor and Nu were increased by 2% and 21% respectively at all Res Sajadi and Kazemi …”

Convective Heat Transfer and Friction Factor Characteristics in Internally Threaded Tube with Constant Heat Flux for Al2O3/Water Nanofluid

“…This approach induces secondary recirculation to the axial flow, leading to an increase in tangential and radial turbulent fluctuation and thus reducing a thickness of the boundary layer. Using nanofluid together with twisted taped for heat transfer enhancement was reported in numerous research works such as twisted tape inserts with Al 2 O 3 /water nanofluid [7] and [8], helical twist tape inserts with Al 2 O 3 /water nanofluid [9], twisted tape with alternate axis inserts with CuO/water nanofluid [10], twisted tape inserts with CuO/water nanofluid in corrugated tube [11], dual twisted tape inserts with CuO/water nanofluid in micro-fin tube [12], helical screw tape inserts with Al 2 O 3 /water nanofluids [13], helical screw tape inserts using CuO/water nanofluids [14], and propeller inserts with TiO 2 /water nanofluid [15].…”