Buoyancy-driven heat transfer performance, vorticity and fluid flow analysis of hybrid nanofluid within a U-shaped lid with heated corrugated wall

Abstract

The thermal performance of alumina-copper/water hybrid nanofluid in buoyancy-driven heat transfer of a U-shaped cavity with a heated wavy wall is investigated in detail throughout this manuscript. A three-node triangular finite element method is used to solve the system by considering the Galerkin weighted residual algorithm. A Newton–Raphson algorithm with a damping coefficient is used as the convergence criterion. Numerical and experimental comparisons of previously published results are compared with the present calculations to ensure confidence in the present modeling. The physical representation of the modeling is presented through the streamlines, isotherms, and vorticity distribution. To quantify the overall heat transfer performance, the average and local Nusselt numbers are used for various combinations of parameters. It is found that the higher the cold rib dimension, the undulations, and the amplitudes of the heated corrugated walls produce a higher heat transfer rate. The inclusion of a hybrid nanofluid may inhibit the heat transfer rate when the length of the hot wall exceeds the length of the cold wall. As low as 4% and up to 16% thermal performance increase of utilizing hybrid nanofluid is observed compared to pure water in a wavy U-shaped enclosure.