Experimental assessment of heat transfer and pressure drop of nanofluid as a coolant in corrugated channels

Over the last few decades, tremendous consideration is drawn towards corrugation surfaces because of their advantages over the improvement in thermal performance for different engineering applications. An experimental investigation is carried out to compare the effects of combined corrugated walls and turbulent nanofluid flow on thermo-hydraulic performance in corrugated channels over Reynolds number ranges of 10,000–30,000 and constant heat flux of 1 × 104 W m−2. Three shapes, namely semicircle corrugated channel, trapezoidal corrugated channel (TCC), and straight channel, are fabricated and tested with 1% and 2% volume fraction of Al2O3–water nanofluids. Al2O3 nanoparticles suspended in water with two volume fractions (ϕ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\phi$$\end{document}) of 1.0% and 2.0% are successfully prepared and tested. The experimental findings demonstrate that employing corrugated channel (TCC) improves heat transfer levels by up to 63.59%, pressure drop by 1.37 times, and thermal performance by up to 2.22 times compared to straight channels. Furthermore, heat transfer increased as Al2O3’s volume fraction increases due to the thermal conductivity boost. The use of the tested channels and alumina nanofluid at a volume fraction of 2.0% caused an increase in the heat transfer ratio of around 7.9–8.3% compared to the utilization of the same channels with base fluid. New empirical correlations of corrugated channels with alumina nanofluid are also developed and reported for heat transfer applications.