Part of #Forced convection of CuO/water nanofluid in Horizontal Annuluses with rotating inner cylinder# :
Publishing year : 2014
Conference : Twenty-second Annual Conference of Mechanical Engineering
Number of pages : 6
Abstract: The specifications of the forced convective heat transfer of CuO / water nanofluid were simulated in conditions of turbulent flow in concentric annulus with rotating inner cylinder. The comparison between predicted and experimental data of Nusselt numbers was found to be in good agreement. The CFX solver is used numerically to solve the governing equations. The uniform wall temperatures are considered as thermal boundary conditions. Solutions for the same axial and rotational velocity and the Nusselt number are obtained for different values of the nanoparticle volume fraction and the Reynolds number. In addition, the effects of change of the external cylinder diameter on heat transfer are also investigated. Simulations show that the increase in inlet / rotating velocity will increase heat transfer. When the inlet velocity increases, it increases the axial velocity near the walls and reduces the rotational velocity at the mid-gap to achieve the conservation of the mass due to the secondary flow in the annulus. On the other hand, the increase of the rotating speed imposes the higher temperature gradients and higher heat transfer rate. Moreover, the increasing rate of Nusselt number is substantially less than the corresponding increase in high aspect ratio.