Effects of binary hybrid nanofluid on heat transfer and fluid flow in a triangular-corrugated channel: an experimental and numerical study

Abstract

The flow and heat transfer over a modulated surface in the form of triangular protrusions using MWCNTs-TiO2 nanohybrids were investigated, and its results are detailed in this paper. The nanomaterials were functionalized and prepared at weight concentrations of 0.025%-wt., 0.05%-wt., 0.075%-wt., and 0.1%-wt., then had its morphology elucidated using the high-resolution transmission electron microscopy (HR-TEM), field emission transmission electron microscopy (FE-SEM), and Energy Dispersive X-Ray Analysis (EDX). The mixture's thermophysical properties at 303 K were determined and utilized in the investigation's numerical aspect. A steady-state 2D analysis of flow over a modulated surface was solved in ANSYS-FLUENT with turbulent flow at 5000 ≤ Re ≤ 15,000. The model was validated using the Dittus-Boelter Eq., and its average error was 9.840%. The heat transfer was enhanced by 13.181%, 18.056%, 22.033% and 26.107% for nanoparticles' weight concentrations of 0.025%-wt., 0.05%-wt., 0.075%-wt., and 0.1%-wt., respectively. The water flow and MWCNTs-TiO2 nanohybrids' turbulent kinetic energy, pressure, velocity, turbulence intensity contours, and velocity vectors were determined, and correlations were formed from the results to predict the average Nusselt number for the DW and MWCNTs-TiO2 as a function of the nanoparticles' weight concentrations.