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Bai and Wang Nanoscale Research Letters 2011, 6:240

Bai and Wang Nanoscale Research Letters 2011, 6:240 http://www.nanoscalereslett.com/content/6/1/240 NANO EXPRESS Open Access Constructal blade shape in nanofluids Chao Bai, Liqiu Wang* Abstract Blade configuration of nanofluids has been proven to perform much better than dispersed configuration for some heat conduction systems. The analytical analysis and numerical calculation are made for the cylinder–shaped and regular-rectangular-prism–shaped building blocks of the blade-configured heat conduction systems (using nanofluids as the heat conduction media) to find the optimal cross-sectional shape for the nanoparticle blade under the same composing materials, composition ratio, volumetric heat generation rate, and total building block volume. The regular-triangular-prism–shaped blade has been proven to perform better. | Bai and Wang Nanoscale Research Letters 2011 6 240 http www.nanoscalereslett.eom content 6 1 240 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Constructal blade shape in nanofluids Chao Bai Liqiu Wang Abstract Blade configuration of nanofluids has been proven to perform much better than dispersed configuration for some heat conduction systems. The analytical analysis and numerical calculation are made for the cylinder-shaped and regular-rectangular-prism-shaped building blocks of the blade-configured heat conduction systems using nanofluids as the heat conduction media to find the optimal cross-sectional shape for the nanoparticle blade under the same composing materials composition ratio volumetric heat generation rate and total building block volume. The regular-triangular-prism-shaped blade has been proven to perform better than all the other three kinds of blades namely the regular-rectangular-prism-shaped blade the regular-hexagonal-prism-shaped blade and the cylinder-shaped blade. Thus the regular-triangular-prism-shaped blade is selected as the optimally shaped blade for the two kinds of building blocks that are considered in this study. It is also proven that the constructal cylinder-regular-triangular-prism building block performs better than the constructal regular-rectangular-prismregular-triangular-prism building block. Introduction Nanofluids are mixtures of nanoparticles and base fluids which have different thermal conductivities 1-5 . They were identified and proposed as a result of people s persistent pursuit for more and more efficient heat-transfer media. It should be noted that conventional heat transfer fluids have normally very low thermal conductivity thus destroying much exergy during heat transport. At present a great amount of attention is paid to studies on nanofluids with the aim of addressing many unsolved issues 6-10 . Constructal theory is a novel thought for nature and society 11-17 . It tries to explain