Natural convection of Cu-H2O nanofluid inside hexagonal enclosure fitted with a square cavity with a non-uniformly heated wall(s)

Abstract

Numerical simulations are undertaken to investigate the flow of fluids and heat transfer through a nanofluid inside a hexagonal enclosure fitted with a square cavity and characterized by buoyancy-driven fluid motion. A periodic hot temperature Th and cold temperature Tc respectively, with Th > Tc is maintained on the parallel walls of the cavity on a regular basis. The Galerkin finite element method discretizes the equations in two dimensions. Stabilized solutions are obtained by using an upwind scheme. Based on the developed code, a parametric study of fluid flow and heat transfer inside the cavity is conducted to study the effects of the Rayleigh number. As the Rayleigh number and nanoparticle volume fraction increase from 101to106, the Nusselt number increases as well. Additionally, the bottom-middle and middle locations of the thermally active parts have the highest average Nusselt numbers for the high and low Rayleigh numbers. The novelty and originality of the proposed work lie in the exploration of a unique hexagonal cavity geometry, the parametric study involving varying Rayleigh numbers and nanoparticle volume fractions, and the utilization of numerical simulations with advanced computational techniques. These contributions enhance the understanding of nanofluid behavior and provide valuable insights for optimizing heat transfer systems in various applications.

Keywords

• Heat transfer
• Finite element method
• Rayleigh number
• Hexagonal cavity