Effects of vertically embedded parallel hot elliptic obstacles inside a fully sinusoidal enclosure filled with SWCNT–water nanofluid

Abstract

Advancements in nanotechnology, particularly the use of nanofluids for heat transfer, have been receiving significant attention for improving the efficacy of heat transfer in systems that employ thermal, electronic, medical, and transportation applications. The thermal performance of a two-dimensional, incompressible flow of single-wall carbon nanotube (SWCNT)–water nanofluid inside a completely sinusoidal enclosure under cold boundary conditions was examined numerically. The impacts of two vertically embedded parallel elliptical hot obstacles have been discussed with respect to thermal radiation. The consequences of flow and thermal control parameters such as the Rayleigh number (104 ≤ RaE ≤ 106), volume fraction of SWCNTs (1.5% ≤ ς ≤ 5.5%), and radiation parameters (0 ≤ Nr ≤ 2) with elliptical obstacles of different sizes were studied through streamlines, isolines, and local and mean Nusselt number plots. To analyze the radiation impact, Rosseland thermal radiation was incorporated into the energy equation. A modified correlation for the thermal conductivity of the SWCNT and base fluid was considered. The Galerkin finite element method was applied to numerically solve the dimensionless equations with appropriate boundary conditions. The mean Nusselt number increased with the increasing size of the vertical semi-major axes of the elliptical obstacles.

Keywords

• Convection
• Heat transfer
• Nanofluid
• Single wall carbon nanotubes
• Sinusoidal enclosure
• Thermal radiation