Convegni ATI - Accesso riservato soci CTI

Autore: O. Manca, S. Nardini, D. Ricci, S. Tamburrino

Collana: CA - 66 - Rende 2011

Note:
In this paper a numerical investigation on turbulent forced convection of a water–Al2O3 nanofluid in a triangular channel is accomplished. A constant and uniform heat flux on the external surfaces has been applied and a single-phase model approach has been employed. The analysis has been performed in steady state regime for particle size, suspended in the base fluid, equal to 38 nm. The CFD commercial code Fluent has been employed in order to solve the tri-dimensional numerical model. The geometrical configuration consists in a duct with a triangular shaped cross area. The base fluid is water and nanoparticles are made up of alumina (Al2O3). The duct length and the edge one is 1.0 m and 0.017 m, respectively. In this way, the hydraulic diameter is set equal to 0.01 m. Different nanoparticle volume fractions and a single-phase model have been considered in order to study a steady turbulent flow with Reynolds number values, ranging from 10000 to 60000. Results are presented in terms of temperature and velocity distributions, surface shear stress and heat transfer convective coefficient, Nusselt number and required pumping power profiles. Comparisons with the results, related to the fluid-dynamic and thermal behaviour, are carried out in order to evaluate the enhancement due to the presence of nanoparticles in terms of volumetric concentration. An increase in terms of average convective heat transfer coefficient was observed for increasing nanoparticle concentrations as well as wall shear stress.