Lattice Boltzmann simulation of natural convection heat transfer of SWCNT-nanofluid in an open enclosure

Abstract

The effects of Single Walled Carbon Nanotube and Copper nanoparticles on natural convection heat transfer in an open cavity are investigated numerically. The problem is studied for different volume fractions of nanoparticles (0–1%) and aspect ratio of the cavity (1–4) when Rayleigh number varies from 103 to 105. The volume fraction of added nanoparticles to Water is lower than 1% to make a dilute suspension. Although, results show that adding nanoparticles to the base fluid enhances the heat transfer, make a comparison between SWCNT and Cu-nanoparticles shows that the SWCNT-nanoparticle has better performance to enhance the convection rate. It is found that the aspect ratio of the cavity plays an important role on natural convection. An increase of this parameter leads to heat transfer reduction in the target problem. It is concluded that the Carbon Nanotubes can be applied as a passive way to enhance heat transfer in convection problems.

Keywords

• Lattice Boltzmann Method
• Single Walled Carbon Nanotube (SWCNT)
• Effective thermal conductivity
• Effective viscosity
• Natural convection
• Open-ended cavity