Natural convection within water-zno nanofluid-filled hemispherical enclosure with a cubic electronic device

This work qualifies and quantifies the nanofluidic natural convective phenomena occurring in a hemispherical enclosure used for electronics applications. This cavity consists of a disk thermally insulated on its rear face, an active cube centered on the disk which generates a constant heat flux and an isothermal dome. The disc of the cavity remains horizontal while its dome is oriented either upwards or downwards. The considered nanofluid is a mixture of water with metallic ZnO nanoparticles. In order to examine the influence of these nanoparticles on the natural convective heat transfer, three values of the volume fraction considered: 0% (pure water), 1% and 5%. The dimensionless governing system of the problem under consideration is solved by means of the control volume method in combination with the SIMPLE algorithm. The structured mesh is composed of triangular surfacic elements and tetrahedral in the volumic domain. Temperature and velocity distributions are presented for some configurations and convective heat transfer is examined for all processed ones. The natural convective heat transfer is quantified by means of Nusselt-Rayleigh-Prandtl correlations.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

Aerodynamics in the open channel of the Sistan-type wind-mill with vertical axis wind turbine

International Journal of Numerical Methods for Heat and Fluid FlowThe purpose of this paper is to examine the details of the air mass flow and aerodynamical phenoména across a channel containing a large vertical axis wind turbine. The considered model reproduces as closely as possible the real assembly of the Sistan-type wind-mill whose top is open. The technical results of this work could be used for the restoration and operation of this assembly whose historical and architectural values are recognized.L'objectif de cet article est d’examiner les détails d'un écoulement dans un canal contenant une turbine à axe vertical. Les résultats techniques de ce travail pourront être utilisés pour la restauration et la mise en service de ce dispositif dont la valeur historique et architecturale est reconnue