Convective heat transfer analysis in turbulent nanofluid flow through a rectangular channel with staggered obstacles: A numerical simulation

Abstract

This study explores the hydraulic and thermal characteristics of a staggered rectangular baffled channel. The first baffle is inserted in the top channel surface, with subsequent baffles placed on the bottom. Numerical simulations were conducted across a Reynolds number range of 5000 to 50,000. In this study three different baffle inclination angles are examined: Case A involves staggered obstacles perpendicular to the channel wall, while Cases B and C feature obstacles inclined at ±10 ° to the channel surface. Three different types of nanoparticles (SiO2, Al2O3, and CuO) are added to the base fluid (pure water) at a volume fraction of 4 % to formulate the nanofluids utilized in this study. Computational Fluid Dynamics (CFD) simulations were performed using ANSYS Fluent software, to solve the governing equations. The numerical results were validated against experimental data, demonstrating good agreement. The findings reveal that the maximum thermal enhancement factor is 2 at a Reynolds number of 5000 for Case A. Additionally, the heat transfer coefficient experiences a 10.3 % increase for water-CuO nanofluid compared to pure water in Case A. The highest average Nusselt number is observed with pure water, reaching 812 for Case C at a Reynolds number of 50,000.

Keywords

• Turbulent flow
• Staggered obstacles
• Nanofluid
• Thermal enhancement factor (TEF)