Unsteady free convection flow of water-based carbon nanotubes due to non-coaxial rotations of moving disk

Abstract

Nanofluid is one of the significant developments for having an efficient heat transport process. Its implementation in a non-coaxial rotating system has benefited from designing a mixer machine with two stirrer blades, a cooling fan, and jet engines. This study analytically investigates the free convection of unsteady non-coaxial rotating nanofluid flow through a moving disk. The suspension of single-wall or multi-wall carbon nanotubes in water is known as the nanofluid in this study. The fluid motion is affected by the effects of rotation and buoyancy forces. Using suitable dimensionless variables, the dimensional coupled partial differential of momentum and energy equations along with their initial and moving boundary conditions are converted into dimensionless form. The expressions for temperature and velocity profiles are obtained by solving governing equations using Laplace transform method. The validity of obtained solution is confirmed by having a good agreement when comparing present results with the published result. The results show that the insertion of CNTs particles into the rotating water causes the temperature and velocity profiles to increase. The amount of heat transferred by SWCNTs is greater than MWCNTs. Increasing CNTs particles have descended both primary and secondary skin friction but increased Nusselt number. Further analysis with the help of pictorial discussion for the fluid flows and heat transfer under the influences of nanoparticle volume fraction, Grashof number, the amplitude of disk, and time is carried out.

Keywords

• non-coaxial rotation
• nanofluid
• carbon nanotubes
• laplace transform method
• moving disk