Convective Heat Transfer Performance of Nanofluid in a Horizontal Annular Duct Considering Nanoparticles Shapes Effect

Abstract

In The present study investigates laminar forced convection heat transfer in a concentric annular space saturated with nanofluids. The inner cylinder is adiabatic while the outer cylinder is uniformly heated. The governing equations with the appropriate boundary conditions are discretized by the finite volume method with second order precision and solved by using the SIMPLER and Thomas algorithms. The effects of some parameters such as the nanoparticles types Ag and CuO, the shapes like blades, platelets, cylinder and bricks, and nanofluid volume fraction on heat transfer are completely studied and discussed. The results show that the Nusselt number, the bulk, and wall temperatures increase with the increase of nanoparticle volume fraction. A linear increase is observed for the average Nusselt number by increasing the volume fraction. Silver nanoparticles Ag give better heat transfer compared with the CuO nanoparticles for the blade shape followed by the elongated shape like platelet and cylinder and in last place brick shape.