Thermal performance analysis for moderate Rayleigh numbers of Newtonian hybrid nanofluid-filled U-shaped cavity with various thermal profiles

Abstract

The numerical study of natural convection heat transfer inside a U-shaped enclosure with various thermal profiles by using copper-alumina/water hybrid nanofluid is reported. The study focuses on the effect of constant, linear, quadratic, and sinusoidal with different amplitudes and periods and absolute sinusoidal thermal profiles to the heat transfer efficiency inside the lid. A weighted residual Galerkin triangular finite element method is used alongside the damped Newton-Raphson algorithm to calculate the heat transfer rate of the system in terms of averaged and local Nusselt number. The result from the present model is compared with the previously published experimental and numerical data. The isotherms and streamlines of the fluid flow for each thermal profile are presented with a nanoparticle volume fraction of between 0 and 0.1 for Rayleigh number of 104-106. It is found that the constant heating profile gives the best heat dissipation performance, while the sinusoidal thermal profile performed the worst. The results gained from this paper will be useful in understanding how heat can be transferred effectively as it can be applied to many different industries, including the electronics field.