Analysis of natural convection of Cu and TiO2nanofluids inside nonconventional enclosures

Steady-state laminar natural convection of Cu and TiO2 nanofluids inside different enclosures is numerically investigated. Natural convection is concerned due to a temperature difference between the hot and cold surfaces. The Boussinesq approximation is used to form the governing equations and the commercial software package ANSYS FLUENT version 14.0 is used to numerically solve the governing equations. The temperature profiles and flow patterns at different Rayleigh numbers, i.e., 104, 105and 106 are studied and compared for different curved geometries which are 1/8, 2/8 and 3/8 of the height of the enclosure. Heat transfer coefficients are presented for enclosures with different nanofluid concentrations. The nanoparticles enhance the heat transfer. The heat transfer enhancement increases with increasing nanoparticle concentrations. A new curved enclosure is suggested to augment heat transfer