Free convection in a porous horizontal cylindrical annulus with a nanofluid using Buongiorno's model

Natural convection flow in a porous concentric horizontal annulus saturated with a water based nanofluid is numerically investigated. The mathematical model used is of single-phase and is formulated in dimensionless stream function and temperature taking into account the Darcy-Boussinesq approximation and the nanofluid model proposed by Buongiorno. The transformed dimensionless partial differential equations have been solved using a second-order accurate finite-difference technique. The results indicate that inclusion of nanoparticles into pure water changes the flow structure at low values of the Rayleigh number.