Experimental Study of Mixed Convection Laminar Flow of Water-Al_2O_3 Nanofluid in Horizontal Tube with Uniform Wall Heat Flux

摘要

In this work, an experimental investigation was carried out to study a laminar mixed convection flow and heat transfer of Al_2O_3-water nanofluid inside a horizontal tube submitted to a uniform wall heat flux at its outer surface. Measured data were collected for the following ranges of the governing parameters: the Reynolds number between 170 and 630, the Grashof number between 1.5×10~4 and 9.2×10~4 and the Prandtl number between 7 and 7.42. Results have shown that the experimental heat transfer coefficient remains nearly constant with an increase of particle volume concentration from 0 to 2%. However, we have observed a slight decrease of the Nusselt number with an increase of the particle volume fraction from 0 to 2%.