An experimental study of forced convective heat transfer for fully developed Al 2 O 3 –water nanofluid in an annulus tube

• Published in: Heat transfer (Hoboken, N.J. Print) N.J. Print), 2021-09, Vol.50 (6), p.5697-5713
• Main Authors: Ghanbari, Khalil, Golneshan, Ali Akbar, Yazdani, Mohsen, Moghadasi, Hesam, Malekian, Navid
• Format: Article
• Language: English
• Subjects: forced convection; fully developed; heat transfer coefficient; nanofluid; Nusselt number
• ISSN: 2688-4534; 2688-4542
• DOI: 10.1002/htj.22144

Nanofluids have been known as practical materials to ameliorate heat transfer within diverse industrial systems. The current work presents an empirical study on forced convection effects of Al2O3–water nanofluid within an annulus tube. A laminar flow regime has been considered to perform the experiment in high Reynolds number range using several concentrations of nanofluid. Also, the boundary conditions include a constant uniform heat flux applied on the outer shell and an adiabatic condition to the inner tube. Nanofluid particle is visualized with transmission electron microscopy to figure out the nanofluid particles. Additionally, the pressure drop is obtained by measuring the inlet and outlet pressure with respect to the ambient condition. The experimental results showed that adding nanoparticles to the base fluid will increase the heat transfer coefficient (HTC) and average Nusselt number. In addition, by increasing viscosity effects at maximum Reynolds number of 1140 and increasing nanofluid concentration from 1% to 4% (maximum performance at 4%), HTC increases by 18%.