Open Access Highly Accessed Open Badges Nano Express

Numerical evaluation of laminar heat transfer enhancement in nanofluid flow in coiled square tubes

Agus Pulung Sasmito12, Jundika Candra Kurnia1* and Arun Sadashiv Mujumdar12

Author affiliations

1 Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576 Singapore

2 Minerals, Metals and Materials Technology Centre, National University of Singapore, 9 Engineering Drive 1, Singapore 117576 Singapore

For all author emails, please log on.

Citation and License

Nanoscale Research Letters 2011, 6:376  doi:10.1186/1556-276X-6-376

Published: 9 May 2011


Convective heat transfer can be enhanced by changing flow geometry and/or by enhancing thermal conductivity of the fluid. This study proposes simultaneous passive heat transfer enhancement by combining the geometry effect utilizing nanofluids inflow in coils. The two nanofluid suspensions examined in this study are: water-Al2O3 and water-CuO. The flow behavior and heat transfer performance of these nanofluid suspensions in various configurations of coiled square tubes, e.g., conical spiral, in-plane spiral, and helical spiral, are investigated and compared with those for water flowing in a straight tube. Laminar flow of a Newtonian nanofluid in coils made of square cross section tubes is simulated using computational fluid dynamics (CFD)approach, where the nanofluid properties are treated as functions of particle volumetric concentration and temperature. The results indicate that addition of small amounts of nanoparticles up to 1% improves significantly the heat transfer performance; however, further addition tends to deteriorate heat transfer performance.