Experimental investigation of convective heat transfer of Al 2 O 3 /water nanofluid in circular tube 1 Paper review

Outline  Introduction  Experimental set-up  Data analysis  Experimental results  Conclusion 2

Introduction Choi at the Argonne National Laboratory was the first to employ the particles of nanometer dimension suspended in solution as nanofluid and showed considerable increase in the nanofluid thermal conductivity. Choi at the Argonne National Laboratory was the first to employ the particles of nanometer dimension suspended in solution as nanofluid and showed considerable increase in the nanofluid thermal conductivity. Lee et al. reported that the suspension of 4.0%volume 35 nm CuO particles in ethylene glycol showed20% increase in thermal conductivity. Lee et al. reported that the suspension of 4.0%volume 35 nm CuO particles in ethylene glycol showed20% increase in thermal conductivity. Choi et al. observed 160% enhancement in thermal conductivity ofengine oil with 1.0% volume carbon nanotube. Choi et al. observed 160% enhancement in thermal conductivity ofengine oil with 1.0% volume carbon nanotube. 3

Xuan and Li investigated heat transfer of Cu/water nanofluid under constant wall heat flux in turbulent flow regime and concluded that convective heat transfer enhancement of nanofluid may be related to thermal conductivity increase or random movement and dispersion of nanoparticles in nanofluid. Xuan and Li investigated heat transfer of Cu/water nanofluid under constant wall heat flux in turbulent flow regime and concluded that convective heat transfer enhancement of nanofluid may be related to thermal conductivity increase or random movement and dispersion of nanoparticles in nanofluid. Wen and Ding have studied Al 2 O 3 /water nanofluid heat transfer in laminar flow under constant wall heat flux and reported an increase in nanofluid heat transfer coefficient with Reynolds number and nanoparticles concentration particularly at the entrance region. Wen and Ding have studied Al 2 O 3 /water nanofluid heat transfer in laminar flow under constant wall heat flux and reported an increase in nanofluid heat transfer coefficient with Reynolds number and nanoparticles concentration particularly at the entrance region. The aim of the present paper is to study laminar flow convective heat transfer of Al 2 O 3 /water nanofluid under constant wall temperature and different concentrations of nanoparticles. The aim of the present paper is to study laminar flow convective heat transfer of Al 2 O 3 /water nanofluid under constant wall temperature and different concentrations of nanoparticles. 4

Experimental set-up 5

Experimental results 6

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Conclusion The experimental results indicate that heat transfer coefficient of nanofluids increases with Peclet number as well as nanoparticles concentration. The experimental results indicate that heat transfer coefficient of nanofluids increases with Peclet number as well as nanoparticles concentration. It is concluded that thermal conductivity increase is not the sole reason for heat transfer enhancement in nanofluids. It is concluded that thermal conductivity increase is not the sole reason for heat transfer enhancement in nanofluids. Other factors such as dispersion and chaotic movement of nanoparticles, Brownian motion and particle migration may play role in heat transfer augmentationdue to nanoparticles. Other factors such as dispersion and chaotic movement of nanoparticles, Brownian motion and particle migration may play role in heat transfer augmentationdue to nanoparticles. Particle fluctuations and interactions,especially in high Peclet number may cause the change in flow structure and lead to augmented heat transfer due to the presence of nanoparticles. Particle fluctuations and interactions,especially in high Peclet number may cause the change in flow structure and lead to augmented heat transfer due to the presence of nanoparticles. 13

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